US20090109955A1 - Method and apparatus for improved frame synchronization in a wireless communication network - Google Patents
Method and apparatus for improved frame synchronization in a wireless communication network Download PDFInfo
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- US20090109955A1 US20090109955A1 US12/262,159 US26215908A US2009109955A1 US 20090109955 A1 US20090109955 A1 US 20090109955A1 US 26215908 A US26215908 A US 26215908A US 2009109955 A1 US2009109955 A1 US 2009109955A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/69—Spread spectrum techniques
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W52/00—Power management, e.g. TPC [Transmission Power Control], power saving or power classes
- H04W52/02—Power saving arrangements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W92/00—Interfaces specially adapted for wireless communication networks
- H04W92/04—Interfaces between hierarchically different network devices
- H04W92/10—Interfaces between hierarchically different network devices between terminal device and access point, i.e. wireless air interface
Definitions
- This disclosure relates generally to wireless communication systems and, more particularly, to wireless data transmission in a wireless communication system.
- devices with a physical (PHY) layer supporting either single carrier or Orthogonal Frequency Division Multiplexing (OFDM) modulation modes may be used for millimeter wave communications, such as in a network adhering to the details as specified by the Institute of Electrical and Electronic Engineers (IEEE) in its 802.15.3c standard.
- the PHY layer may be configured for millimeter wave communications in the spectrum of 57 gigahertz (GHz) to 66 GHz and specifically, depending on the region, the PHY layer may be configured for communication in the range of 57 GHz to 64 GHz in the United States and 59 GHz to 66 GHz in Japan.
- GHz gigahertz
- both modes further support a common mode.
- the common mode is a single-carrier base-rate mode employed by both OFDM and single-carrier transceivers to facilitate co-existence and interoperability between different devices and different networks.
- the common mode may be employed to provide beacons, transmit control and command information, and used as a base rate for data packets.
- a single-carrier transceiver in an 802.15.3c network typically employs at least one code generator to provide spreading of the form first introduced by Marcel J. E. Golay (referred to as Golay codes), to some or all fields of a transmitted data frame and to perform matched-filtering of a received Golay-coded signal.
- Golay codes are sets of finite sequences of equal length such that a number of pairs of identical elements with any given separation in one sequence is equal to the number of pairs of unlike elements having the same separation in the other sequences.
- GMSK Continuous Phase Modulated
- BT bandwidth time product
- GMSK pulse shapes For example, ⁇ /2-binary phase shift key (BPSK) modulation (or ⁇ /2-differential BPSK) with a linearized GMSK pulse may be implemented, such as shown in I. Lakkis, J. Su, & S. Kato, “A Simple Coherent GMSK Demodulator”, IEEE Personal, Indoor and Mobile Radio Communications (PIMRC) 2001, which is incorporated by reference herein, for the common mode.
- BPSK phase shift key
- PIMRC Personal, Indoor and Mobile Radio Communications
- WPANs millimeter-wave wireless personal area networks
- IEEE802.15.3c IEEE802.15.3c
- a method of communication is provided. More specifically, a packet is generated and such packet has a header that comprises location information of the packet with respect to a beacon. Thereafter, the packet is transmitted, wherein the packet and the beacon are transmitted within a superframe.
- a communication apparatus comprises means for generating a packet having a header that comprises location information of the packet with respect to a beacon and means for transmitting the packet, wherein the packet and the beacon are transmitted within a superframe.
- an apparatus for communications comprises a processing system configured to generate a packet having a header that comprises location information of the packet with respect to a beacon and transmit the packet, wherein the packet and the beacon are transmitted within a superframe.
- a computer-program product for wireless communications comprises a machine-readable medium encoded with instructions executable to generate a packet having a header that comprises location information of the packet with respect to a beacon and transmit the packet, wherein the packet and the beacon are transmitted within a superframe.
- a method of communication is provided. More specifically, a packet is received and such packet has a header that comprises location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe. Thereafter, the location information is used to determine a location within the superframe.
- a communication apparatus comprises means for receiving a packet having a header that comprises location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe and means for using the location information to determine a location within the superframe.
- an apparatus for communications comprises a processing system configured to receive a packet having a header that comprises location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe and use the location information to determine a location within the superframe.
- a computer-program product for wireless communications comprises a machine-readable medium encoded with instructions executable to receive a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe and use the location information to determine a location within the superframe.
- a method for wireless communication is provided. More specifically, a packet is generated and such packet comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion. Thereafter, the packet is transmitted.
- a communication apparatus comprises means for generating a packet that comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion and means for transmitting the packet.
- a communication apparatus comprises a processing system configured to generate a packet that comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion and transmit the packet.
- a computer-program product for communications comprises a machine-readable medium encoded with instructions executable to generate a packet that comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion and transmit the packet.
- a method of communication is provided. More specifically, a payload of a packet is divided into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes and information is inserted between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation. Thereafter, the packet is transmitted.
- an apparatus for communication comprises means for dividing a payload of a packet into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes, means for inserting information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation and means for transmitting the packet.
- an apparatus for wireless communications comprises a processing system configured to divide a payload of a packet into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes, insert information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation and transmit the packet.
- a computer-program product for communication comprises a machine-readable medium encoded with instructions executable to divide a payload of a packet into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes, insert information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation and transmit the packet.
- FIG. 1 is a diagram of a wireless network configured in accordance with an aspect of the disclosure
- FIG. 2 is a diagram of a superframe timing configured in accordance with an aspect of the disclosure that is used in the wireless network of FIG. 1 ;
- FIG. 3 is a diagram of a superframe structure configured in accordance with an aspect of the disclosure that is used in the wireless network of FIG. 1 ;
- FIG. 4 is a diagram of a frame/packet structure configured in accordance with an aspect of the disclosure that is used in the superframe structure of FIG. 3 ;
- FIG. 5 is a diagram of an improved frame/packet structure that supports signaling for multiple header rates in accordance with an aspect of the disclosure
- FIG. 6 is a diagram of multiple start frame delimiters that may be used in accordance with an aspect of the disclosure.
- FIG. 7 is a diagram of an improved frame/packet structure that supports signaling for superframe timing detection in accordance with an aspect of the disclosure
- FIG. 8 is a flow chart illustrating a process for determining superframe timing information in accordance with an aspect of the disclosure
- FIG. 9 is a diagram of an improved frame/packet structure that supports improved carrier estimation in accordance with an aspect of the disclosure.
- FIG. 10 is a diagram of a plurality of data blocks that may be used with reduced spectral lines in accordance with an aspect of the disclosure
- FIG. 11 is a circuit diagram of a scrambler configured in accordance with an aspect of the disclosure.
- FIG. 12 is a diagram of an improved frame/packet structure configured for longer data blocks in accordance with an aspect of the disclosure
- FIG. 13 is a circuit diagram of a Golay circuitry configured in accordance with an aspect of the disclosure.
- FIG. 14 is a block diagram of a start frame delimiter generator apparatus configured in accordance with an aspect of the disclosure.
- FIG. 15 is a block diagram of a timestamp generator apparatus configured in accordance with an aspect of the disclosure.
- FIG. 16 is a block diagram of a channel estimation sequence generator apparatus configured in accordance with an aspect of the disclosure.
- FIG. 1 is a network formed in a manner that is compatible with the IEEE 802.15.3c Personal Area Networks (PAN) standard and herein referred to as a piconet.
- the network 100 is a wireless ad hoc data communication system that allows a number of independent data devices such as a plurality of data devices (DEVs) 120 to communicate with each other.
- DEVs data devices
- Networks with functionality similar to the network 100 are also referred to as a basic service set (BSS), or independent basic service (IBSS) if the communication is between a pair of devices.
- BSS basic service set
- IBSS independent basic service
- Each DEV of the plurality of DEVs 120 is a device that implements a MAC and PHY interface to the wireless medium of the network 100 .
- a device with functionality similar to the devices in the plurality of DEVs 120 may be referred to as an access terminal, a user terminal, a mobile station, a subscriber station, a station, a wireless device, a terminal, a node, or some other suitable terminology.
- the various concepts described throughout this disclosure are intended to apply to all suitable wireless nodes regardless of their specific nomenclature.
- PNC PicoNet Coordinator
- FIG. 1 a PNC 110 .
- the PNC includes the same device functionality of the plurality of other devices, but provides coordination for the network.
- the PNC 110 provides services such as basic timing for the network 100 using a beacon; and management of any Quality of Service (QoS) requirements, power-save modes, and network access control.
- QoS Quality of Service
- a device with similar functionality as described for the PNC 110 in other systems may be referred to as an access point, a base station, a base transceiver station, a station, a terminal, a node, an access terminal acting as an access point, or some other suitable terminology.
- the PNC 110 coordinates the communication between the various devices in the network 100 using a structure referred as a superframe. Each superframe is bounded based on time by beacon periods.
- the PNC 110 may also be coupled to a system controller 130 to communicate with other networks or other PNCs.
- FIG. 2 illustrates a superframe 200 used for piconet timing in the network 100 .
- a superframe is a basic time division structure containing a beacon period, a channel time allocation period and, optionally, a contention access period.
- the length of a superframe is also known as the beacon interval (BI).
- BI beacon interval
- BP beacon period
- BP beacon period
- a Contention Access Period (CAP) 220 is used to communicate commands and data either between the PNC 110 and a DEV in the plurality of DEVs 120 in the network 100 , or between any of the DEVs in the plurality of DEVs 120 in the network 100 .
- the access method for the CAP 220 can be based on a slotted aloha or a carrier sense multiple access with collision avoidance (CSMA/CA) protocol.
- the CAP 220 may not be included by the PNC 110 in each superframe.
- a Channel Time Allocation Period (CTAP) 220 which is based on a Time Division Multiple Access (TDMA) protocol, is provided by the PNC 110 to allocate time for the plurality of DEVs 120 to use the channels in the network 100 .
- CTAP is divided into one or more time periods, referred to as Channel Time Allocations (CTAs), that are allocated by the PNC 110 to pairs of devices; one pair of devices per CTA.
- CTAs Channel Time Allocations
- FIG. 3 illustrates, as viewed from a data perspective, a superframe structure 300 as employed by the network 100 .
- the superframe structure 300 begins with a beacon period 302 in which a piconet controller such as the PNC 110 broadcasts various control parameters, including a beacon frame number 310 and a superframe duration 312 . This information is sent via one or more beacon packets (not shown).
- the transmission of a series of data packets 360 follows the beacon period 302 .
- These data packets may be transmitted by the PNC 110 or different devices that are members of the piconet.
- Each beacon period, such as the beacon period 302 , or any data packet, such as the data packet 360 is typically followed by a guard time (GT) 330 .
- GT guard time
- FIG. 4 is an example of a frame structure 400 that may be used for a single carrier, OFDM or common mode frame.
- frame may also be referred to as a “packet”, and these two terms should be considered synonymous.
- the frame structure 400 includes a preamble 402 , a header 440 , and a packet payload 480 .
- the common mode uses Golay codes for all three fields, i.e. for the preamble 402 , the header 440 and the packet payload 480 .
- the common-mode signal uses Golay spreading codes with chip-level ⁇ /2-BPSK modulation to spread the data therein.
- the header 440 which is a physical layer convergence protocol (PLCP) conforming header
- the packet payload 480 which is a physical layer service data unit (PSDU)
- PSDU physical layer service data unit
- Golay codes employed in the preamble may be selected from length-128 or length-256 Golay codes.
- Golay codes used for data spreading may comprise length-64 or length-128 Golay codes.
- the preamble 402 includes a packet sync sequence field 410 , a start frame delimiter (SFD) field 420 , and a channel-estimation sequence field 430 .
- the preamble 402 may be shortened when higher data rates are used.
- the default preamble length may be set to 36 Golay codes for the common mode, which is associated with a data rate on the order of 50 Mbps.
- the preamble 402 may be shortened to 16 Golay codes, and for data rates around 3 Gbps, the preamble 402 may be further shortened to 8 Golay codes.
- the preamble 402 may also be switched to a shorter preamble based upon either an implicit or explicit request from a device.
- the packet sync sequence field 410 is a repetition of ones spread by one of the length-128 complementary Golay codes (a i 128 , b i 128 ) as represented by codes 412 - 1 to 412 - n in FIG. 4 .
- the SFD field 420 comprises a specific code such as ⁇ 1 ⁇ that is spread by one of the length-128 complementary Golay codes (a i 128 , b i 128 ), as represented by a code 422 in FIG. 4 .
- the CES field 430 may be spread using a pair of length-256 complementary Golay codes (a i 256 , b i 256 ), as represented by codes 432 and 436 , and may further comprise at least one cyclic prefix, as represented by 434 - 1 and 438 - 1 , such as a i CP or b i CP , which are length-128 Golay codes, where CP is the Cyclic Prefix or Postfix.
- a cyclic postfix for each of the codes 432 and 436 such as a i CP or b i CP , respectively, as represented by 434 - 2 and 438 - 2 , respectively, are length-128 Golay codes.
- the header 440 employs approximately a rate one-half Reed Solomon (RS) coding, whereas the packet payload 480 employs a rate-0.937 RS coding, RS(255,239).
- the header 440 and the packet payload 480 may be binary or complex-valued, and spread using length-64 complementary Golay codes a i 64 and/or b i 64 .
- the header 440 should be transmitted in a more robust manner than the packet payload 480 to minimize packet error rate due to header error rate.
- the header 440 can be provided with 4 dB to 6 dB higher coding gain than the data portion in the packet payload 480 .
- the header rate may also be adapted in response to changes in the data rate.
- the header rate may be 400 Mbps.
- the header rate may be 800 Mbps, and for a range of data rates up to 6 Gbps, the header rate may be set at 1.5 Gbps.
- a constant proportion of header rate may be maintained to a range of data rates.
- the header rate may be adjusted to maintain a constant ratio of header rate to data-rate range. It is important to communicate the change in header rate to each device in the plurality of DEVs 120 in the network 100 .
- the current frame structure 400 in FIG. 4 used by all modes i.e., single carrier, OFDM and common modes), do not include an ability to do this.
- FIG. 5 illustrates an improved frame structure 500 that supports signaling for multiple header rates and multi PHY modes in accordance with an aspect of the disclosure.
- the frame structure 500 includes a preamble 502 , a header 540 , and a packet payload 580 .
- the header 540 , and packet payload 580 portions are configured in a similar fashion to the header 440 and the packet payload 480 .
- the preamble 502 includes a packet sync sequence field 510 , a start frame delimiter (SFD) code block 520 , and a channel-estimation sequence field 530 .
- SFD start frame delimiter
- the SFD code block 520 comprises three codes SFD 1 522 , SFD 2 524 , and SFD 3 526 .
- a default header rate may be set to corresponds to an SFD code block 620 a , denoted by [ ⁇ 1 +1 +1], where the sign corresponds to the sign of the Golay code transmitted.
- the SFD code block 520 is an SFD code block 620 a , denoted by [ ⁇ 1 +1 ⁇ 1].
- the SFD code block 520 is an SFD code block 620 c , denoted by [ ⁇ 1 ⁇ 1 +1], and for a 1.5 Gbps header rate, the SFD code block 520 is an SFD code block 620 d , denoted by [ ⁇ 1 ⁇ 1 ⁇ 1].
- a set of different SFD code blocks may be constructed using a complementary Golay codes, as indicated by a plurality of SFD code blocks 620 e to 620 h in FIG. 6 .
- the SFD patterns may also be used to provide other information, including differentiating between a single carrier and OFDM packets or differentiating between a beacon packet and a data packet.
- the SFD may be used to indicate a special type of packet used for beamforming.
- the SFD pattern 620 a in FIG. 6 is assigned to beacon packets
- the SFD patterns 620 b , 620 c , and 620 d are assigned to single carrier data packets to differentiate between header rates of 400 Mbps, 800 Mbps, and 1.5 Gbps respectively
- the SFD patterns 620 e , 620 f , 620 g are assigned to OFDM data packets to differentiate between rates of 900 Mbps, 1.5 Gbps, and 3 Gbps respectively
- the SFD pattern 620 h is assigned to beamforming training packets. Any device in the plurality of DEVs 120 that is performing preamble detection will search for these SFD patterns.
- the codes a in the packet sync sequence field 510 may be scrambled by a cover code, such that each code a is multiplied by ⁇ +1 ⁇ or ⁇ 1. ⁇ This may be done to reduce spectral lines that would otherwise result from code repetition in the packet sync sequence field 510 .
- the SFD code block 520 can be encoded with the complementary code b, as illustrated and discussed previously in FIG. 5 and FIG. 6 . Thus, various combinations of a and b may be employed in the SFD code block 520 .
- beacon packets will be sent by the PNC 110 to set the superframe duration, the CAP end time, the time allocations and to communicate management information for the piconet.
- beacon packet number one is transmitted at time zero and the remaining beacon packets contain information about the time offset from the beginning of the superframe.
- any beacon packet to be sent during the beacon period 302 is transmitted using a common-mode signal so that it can be understood by all devices. Further, no device can transmit until it has synchronized itself with the network. Thus, all devices in the plurality of DEVs 120 must attempt to determine whether an existing network exists by detecting the beacon and locating the beginning of a superframe.
- Each device in the wireless network 100 upon start-up, searches for the superframe start time by locking to the beacon period 302 . Because the same Golay code is used for spreading the preambles for both beacon packets and data packets, whether each received segment is a beacon packet or a data packet is determined by decoding the header 440 . However, this can be a problem for low-power devices, especially when long superframes (e.g., 65 ms long) are employed, since the device has to try to decode every packet for up to 20 ms before finding the beacon period. Furthermore, some data packets may employ the same spreading and protection for the header 440 as the beacon 302 , and thus will pass the CRC.
- FIG. 7 illustrates an improved frame structure 700 that supports time stamping and superframe timing information communication.
- the frame structure 700 includes a preamble 702 , a header 740 , and a packet payload 780 .
- the preamble 702 and packet payload 780 portions are configured in a similar fashion to the preamble 402 and the packet payload 480 of the frame structure 400 of FIG. 4 .
- the frame structure 700 further includes a time stamp 742 in the header 740 that provides improved communication of the timing information of the superframe being transmitted.
- the time stamp 742 may be configured to include information to allow any device, once the device has received and decoded the time stamp 742 , to determine one or more of the following pieces of information in the following list, which is presented as examples and is not to be limiting: location information of the transmitted frame within the superframe, the superframe length, the start of the superframe, the end of the superframe, the location of the beacon and a location of the CAP. Collectively, the list of information is referred to herein as the superframe timing information.
- the time stamp 742 can thus assist the device to locate the beacon period.
- the time stamp 742 will be positioned as the first field in the header field 740 so the device can avoid having to decode the entire header and, instead, only decode the portion of the header 740 it needs to determined the superframe timing information it needs.
- Some packets are transmitted without a header (for example, some beamforming packets may be transmitted without headers and payloads), and in this case then the SFD code block 520 may be configured to identify these packets so that the receiving device would know that these packets contain no timing information.
- the SFD code block 520 can use different sets of SFD patterns that are assigned to single carrier and OFDM modes in order for a receiving device to differentiate between single carrier and OFDM packets.
- the time stamp 742 can be compressed to reduce overhead if needed.
- an eight-bit time stamp may be used from which the location of the beacon can be computed, but with less resolution.
- the device may go into a sleep mode to save power and awaken just before the beacon period to detect, for example, the header rate.
- a device in the plurality of DEVs 120 needs to determine the header rate, it can acquire that information by timing the power-up or awakening at a sufficient time before the beacon period.
- FIG. 8 illustrates a superframe timing information acquisition process 800 that may be performed by a device in the plurality of DEVs 120 to acquire superframe timing information in one aspect of the disclosure.
- DEV will initialize and prepare to perform wireless communication with the network 100 .
- the DEV will try to detect the preamble of a beacon frame or data frame. Assuming the detection is successful, the DEV will decode the header, or at least timestamp portion of the header in step 806 . Then, in step 808 , the DEV can determine superframe timing information from the decoded timestamp.
- the DEV may decide to enter into a low-power or sleep mode until the next beacon period to acquire the full information about the superframe being transmitted by the PNC 110 .
- the DEV may put itself to sleep for a predetermined period, such as a period of time sufficient for the current superframe to end.
- the DEV can enter into the sleep mode for more than one beacon period, and periodically awaken to acquire superframe timing information.
- the DEV can still maintain timing synchronization because of its use of the timestamp.
- DEV can attempt to join the network 100 without having to wait for the beacon and CAP phase.
- the DEV may detect whether a particular channel in the network 100 is busy without having to wait to detect a beacon. In this aspect, once the DEV detects a timestamp, it will assume that channel is busy and the move to next channel.
- the timestamp facilitates beacon and superframe timing detection because DEV does not have to decode every packet to determine if a particular packet is a beacon packet. At the most, the DEV just has to decode one timestamp successfully. Thus, the DEV does not have to decode completely the header and possibly data to determine if the packet is a beacon packet or not.
- the timestamp can also be used to improve acquisition of signal and joining of the network by the plurality of DEVs 120 .
- a DEV 120 - 2 is far enough away from the PNC 110 not to have good detection of the beacon transmitted by the PNC 110 .
- the DEV 120 - 1 is closer to the PNC 110 but also close to the DEV 120 - 2 and can reliably detect the beacon from the PNC 110 . Because all devices will include timestamp information in their transmissions and the DEV 120 - 2 can hear the transmissions from DEV 120 - 1 , the DEV 120 - 2 will have a better idea of the beacon location and can alter its operation to improve its chances of receiving the beacon.
- the DEV 120 - 2 can lower its preamble detection threshold during the expected time of beacon transmission from the PNC 110 , which is a function of Signal-to-Noise Ratio (SNR) or Signal-to-Noise/Interference Ratio (SNIR), because it is more certain that a detection will not be a false positive.
- SNR Signal-to-Noise Ratio
- SNIR Signal-to-Noise/Interference Ratio
- preambles for different piconets operating in the same frequency band may employ cover sequences that provide for orthogonality in time and/or frequency.
- a first piconet controller PNC 1 uses a first Golay code a 1281 of length 128, a second piconet controller PNC 2 uses a 1282 , and a third piconet controller PNC 3 uses a 1283 .
- the preamble is formed from 8 repetitions of each Golay code multiplied by an orthogonal covering code, such as shown in the following case:
- PNC1 transmits: +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 +a 1 (cover code[1 1 1 1])
- PNC2 transmits: +a 2 ⁇ a 2 +a 2 ⁇ a 2 +a 2 ⁇ a 2 +a 2 ⁇ a 2 (cover code[1 ⁇ 1 1 ⁇ 1])
- PNC3 transmits: +a 3 +a 3 ⁇ a 3 ⁇ a 3 +a 3 +a 3 ⁇ a 3 ⁇ a 3 (cover code([1 1 ⁇ 1 ⁇ 1])
- periodic orthogonality means that if a first covering code is repeated, such as:
- non-binary cover codes may be provided.
- These codes may be used to multiply a particular Golay code (e.g., a(1)) as follows [a 1 .cover1(1) a 1 .cover1(2) a 1 .cover1(3) a 1 .cover1(4)].
- the Fast Fourier Transform (FFT) of this sequence is nonzero for every fourth subcarrier. If a 1 is of length 128 and the FFT length is 512 (numbered 0:511), then cover1 produces non-zero subcarriers 0, 4, 8, . . . . With cover2, only subcarriers 1, 5, 9, . . are nonzero.
- Cover3 produces non-zero subcarriers 2, 6, 10 . . . , and cover4 produces subcarriers 3, 7, 11, . . . .
- beacons with almost omni-directional antenna patterns are first transmitted.
- Directional beacons i.e., beacons transmitted with some antenna gain in some direction(s)
- a combination of Golay-code length and number of repetitions is adapted to different antenna gains.
- the beacons are transmitted using the common mode with a default preamble comprising 32 repetitions of a length-128 Golay code.
- the beacons employ a shortened preamble of 16 repetitions of the same Golay code.
- the beacons use a shortened preamble of 8 repetitions of the Golay code.
- the beacons employ a shortened preamble of 4 repetitions of the Golay code.
- header and/or data spreading factors may be scaled relative to the antenna gain.
- FIG. 9 illustrates a frame structure 900 in accordance with an aspect of the disclosure.
- the frame structure 900 includes a preamble 902 , a header 940 , and a packet payload 980 .
- the preamble 902 and packet payload 980 portions are configured in a similar fashion to the preamble 902 and the packet payload 480 of the frame structure 900 of FIG. 9 .
- the data portion of the frame which may include the header 940 and includes the packet payload 980 is partitioned into a plurality of blocks 950 - 1 to 950 - n , and each block 950 - 1 to 950 - n is further partitioned into sub-blocks, such as sub-blocks 952 - 1 to 952 - n .
- Each sub-block 952 - 1 to 952 - n is preceded by a known Golay sequence of length L, such as known Golay sequences 954 - 1 to 954 - n , which should be typically longer than the multipath delay spread.
- the last data portion 956 - n is followed by a known Golay sequence 954 -[n+1].
- all known Golay sequences within a particular data block are identical.
- the known Golay sequences functions as a cyclic prefix if a frequency domain equalizer is used. Furthermore, it can be used for timing, frequency, and channel tracking.
- Each data block 950 - 1 to 950 - n is followed by a pilot channel estimation sequence (PCES) 960 having a complementary set of Golay codes 964 - 1 and 968 - 1 each having a CP 962 - 1 and 966 - 2 , respectively.
- the PCES 960 can be used to reacquire the channel if needed, and the repetition period for the PCES 960 can be changed to reduce overhead.
- the PCES period can, for example, be encoded in the header 940 .
- each data block uses a different known Golay sequence, such as shown in FIG. 10 .
- a pair of Golay codes (aL,bL) may be employed, wherein aL and bL denotes a pair of complementary Golay sequences of length L, or a shorter length K ⁇ L protected by its own short cyclic prefix.
- a Golay code-length of 16 may be used with the last 4 samples repeated in the beginning.
- Each data block may use aL, ⁇ aL, bL, or ⁇ bL.
- a scrambler 1100 such as shown in FIG. 11 , may be used for selecting Golay codes aL, ⁇ aL, bL, and ⁇ bL.
- the scrambler 1100 may be implemented as a feedback-shift register. The scrambler 1100 may be used to choose the Golay codes for each data block.
- each data block employs one of the four Golay-code options aL, ⁇ aL, bL, and ⁇ bL for a portion of the data block, and the codes are changed for each portion.
- different block portions 1250 - 1 to 1250 - 5 of a data block 1202 use different Golay codes (e.g., Golay code 1254 - 1 - 1 for block portion 2 1250 - 1 versus Golay code 1254 - 1 - 2 for block portion 2 1250 - 2 ).
- a known sequence can be used both before and after equalization.
- techniques for using a known sequence before and after equalization for timing, frequency and channel tracking are well known in the art.
- aspects of the disclosure may provide for further uses of known Golay sequences.
- After equalization there is a noisy estimate of the known transmitted Golay sequence.
- the residual multipath can be estimated and used for time-domain equalization with a very simple short equalizer (e.g., a two-taps equalizer).
- FIG. 13 is a block diagram of a Golay-code circuitry 1300 that may be employed as a Golay code generator or matched filter in some aspects of the disclosure.
- the Golay-code circuitry 1300 comprises a sequence of delay elements 1302 - 1 to 1302 -M, a sequence of adaptable seed vector insertion elements 1330 - 1 to 1330 -M, a first set of combiners 1310 - 1 to 1310 -M, and a second set of combiners 1320 - 1 to 1320 -M configured for combining delayed signals with signals multiplied by the seed vector.
- the following set of three sequences may be used for the preamble for spatial and frequency reuse to minimize interference between piconets operating in the same frequency band.
- the Delay vectors are denoted by D1, D2, and D3, and corresponding seed vectors are denoted by W1, W2, and W3.
- the first sequence employs Golay code a, and the second and third sequences are type-b sequences.
- the binary sequences (s1, s2, and s3) are provided in hexadecimal format. These sequences are optimized to have minimum sidelobe levels and minimum cross-correlation.
- Common mode data sequences may employ the following set of Golay complementary codes.
- the Golay sequences a and b are of length 64.
- Each symbol carriers 2 bits per symbol. For example, when the 2 bits are “00,” a is transmitted. When the bits are “01,” ⁇ a is transmitted. When the bits correspond to “10,” b is transmitted; and for the bit combination “11”, ⁇ b is transmitted.
- Three pairs of complementary Golay codes are employed for frequency reuse, wherein one pair is used per piconet. These pairs are provided selected to have low cross-correlation between each other and with the preamble. These codes can be used as well as the known sequences before each sub-burst
- the following length-16 and length-8 codes may be used as spreading codes and/or as the known cyclic prefix before each sub-burst.
- sequences of length 128 shown in hexadecimal and generated from the following delay and seed vectors may be provided as the cyclic prefix or for the PCES field.
- the following sequences of length-256 and 512 may be used in the Pilot Channel Estimation Sequences (PCES). These sequences have low cross-correlation with each other and with the preamble.
- PCES Pilot Channel Estimation Sequences
- FIG. 14 illustrates a start frame delimiter generation apparatus 1400 that may be used in various aspects of the disclosure, with a timestamp generation module 1402 for generating a packet that includes a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion; and a packet transmission module 1404 for transmitting the packet.
- a timestamp generation module 1402 for generating a packet that includes a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion
- a packet transmission module 1404 for transmitting the packet.
- FIG. 15 illustrates a timestamp generation apparatus 1500 that may be used in various aspects of the disclosure, with a timestamp generation module 1502 for generating a packet having a header that includes location information of the packet with respect to a beacon; and a timestamp transmission module 1504 for transmitting the packet, wherein the packet and the beacon are transmitted within a superframe.
- a timestamp generation module 1502 for generating a packet having a header that includes location information of the packet with respect to a beacon
- a timestamp transmission module 1504 for transmitting the packet, wherein the packet and the beacon are transmitted within a superframe.
- FIG. 16 illustrates a channel estimation sequence generation apparatus 1600 that may be used in various aspects of the disclosure, with a data block generator module 1602 for dividing a payload of a packet into a plurality of data blocks, wherein each data block includes Golay codes and data portions, and every data portion is between two Golay codes; a channel estimation sequence generation and insertion module 1604 for inserting information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation; and a packet transmission module 1606 for transmitting the packet.
- a data block generator module 1602 for dividing a payload of a packet into a plurality of data blocks, wherein each data block includes Golay codes and data portions, and every data portion is between two Golay codes
- a channel estimation sequence generation and insertion module 1604 for inserting information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation
- a packet transmission module 1606 for transmitting the packet.
- Various aspects described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques.
- article of manufacture as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media.
- computer readable media may include, but are not limited to, magnetic storage devices, optical disks, digital versatile disk, smart cards, and flash memory devices.
- the various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented within or performed by an integrated circuit (“IC”), an access terminal, or an access point.
- the IC may comprise a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute codes or instructions that reside within the IC, outside of the IC, or both.
- a general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine.
- a processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
Abstract
A wireless network uses an improved frame structure to increase timing acquisition capabilities as well as reduction of spectral lines. In one aspect, the frame packet can be used to communicate the different modes of operation under which the packet was created.
Description
- This application claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application Ser. No. 60/984,296, filed Oct. 31, 2007, entitled “Frame Format for UWB System Employing Common Mode Signaling and Beamforming.”
- I. Field of the Disclosure
- This disclosure relates generally to wireless communication systems and, more particularly, to wireless data transmission in a wireless communication system.
- II. Description of the Related Art
- In one aspect of the related art, devices with a physical (PHY) layer supporting either single carrier or Orthogonal Frequency Division Multiplexing (OFDM) modulation modes may be used for millimeter wave communications, such as in a network adhering to the details as specified by the Institute of Electrical and Electronic Engineers (IEEE) in its 802.15.3c standard. In this example, the PHY layer may be configured for millimeter wave communications in the spectrum of 57 gigahertz (GHz) to 66 GHz and specifically, depending on the region, the PHY layer may be configured for communication in the range of 57 GHz to 64 GHz in the United States and 59 GHz to 66 GHz in Japan.
- To allow interoperability between devices or networks that support either OFDM or single-carrier modes, both modes further support a common mode. Specifically, the common mode is a single-carrier base-rate mode employed by both OFDM and single-carrier transceivers to facilitate co-existence and interoperability between different devices and different networks. The common mode may be employed to provide beacons, transmit control and command information, and used as a base rate for data packets.
- A single-carrier transceiver in an 802.15.3c network typically employs at least one code generator to provide spreading of the form first introduced by Marcel J. E. Golay (referred to as Golay codes), to some or all fields of a transmitted data frame and to perform matched-filtering of a received Golay-coded signal. Complementary Golay codes are sets of finite sequences of equal length such that a number of pairs of identical elements with any given separation in one sequence is equal to the number of pairs of unlike elements having the same separation in the other sequences. S. Z. Budisin, “Efficient Pulse Compressor for Golay Complementary Sequences,” Electronic Letters, 27, no. 3, pp. 219-220, Jan. 31, 1991, which is hereby incorporated by reference, shows a transmitter for generating Golay complementary codes as well as a Golay matched filter.
- For low-power devices, it is advantageous for the common mode to employ a Continuous Phase Modulated (CPM) signal having a constant envelope so that power amplifiers can be operated at maximum output power without affecting the spectrum of the filtered signal. Gaussian Minimum Shift Keying (GMSK) is a form of continuous phase modulation having compact spectral occupancy by choosing a suitable bandwidth time product (BT) parameter in a Gaussian filter. The constant envelope makes GMSK compatible with nonlinear power amplifier operation without the concomitant spectral regrowth associated with non-constant envelope signals.
- Various techniques may be implemented to produce GMSK pulse shapes. For example, π/2-binary phase shift key (BPSK) modulation (or π/2-differential BPSK) with a linearized GMSK pulse may be implemented, such as shown in I. Lakkis, J. Su, & S. Kato, “A Simple Coherent GMSK Demodulator”, IEEE Personal, Indoor and Mobile Radio Communications (PIMRC) 2001, which is incorporated by reference herein, for the common mode.
- Aspects disclosed herein may be advantageous to systems employing millimeter-wave wireless personal area networks (WPANs) such as defined by the IEEE802.15.3c protocol. However, the disclosure is not intended to be limited to such systems, as other applications may benefit from similar advantages.
- According to an aspect of the disclosure, a method of communication is provided. More specifically, a packet is generated and such packet has a header that comprises location information of the packet with respect to a beacon. Thereafter, the packet is transmitted, wherein the packet and the beacon are transmitted within a superframe.
- According to another aspect of the disclosure, a communication apparatus comprises means for generating a packet having a header that comprises location information of the packet with respect to a beacon and means for transmitting the packet, wherein the packet and the beacon are transmitted within a superframe.
- According to another aspect of the disclosure, an apparatus for communications comprises a processing system configured to generate a packet having a header that comprises location information of the packet with respect to a beacon and transmit the packet, wherein the packet and the beacon are transmitted within a superframe.
- According to another aspect of the disclosure, a computer-program product for wireless communications comprises a machine-readable medium encoded with instructions executable to generate a packet having a header that comprises location information of the packet with respect to a beacon and transmit the packet, wherein the packet and the beacon are transmitted within a superframe.
- According to another aspect of the disclosure, a method of communication is provided. More specifically, a packet is received and such packet has a header that comprises location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe. Thereafter, the location information is used to determine a location within the superframe.
- According to another aspect of the disclosure, a communication apparatus comprises means for receiving a packet having a header that comprises location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe and means for using the location information to determine a location within the superframe.
- According to another aspect of the disclosure, an apparatus for communications comprises a processing system configured to receive a packet having a header that comprises location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe and use the location information to determine a location within the superframe.
- According to another aspect of the disclosure, a computer-program product for wireless communications comprises a machine-readable medium encoded with instructions executable to receive a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe and use the location information to determine a location within the superframe.
- According to another aspect of the disclosure, a method for wireless communication is provided. More specifically, a packet is generated and such packet comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion. Thereafter, the packet is transmitted.
- According to another aspect of the disclosure, a communication apparatus comprises means for generating a packet that comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion and means for transmitting the packet.
- According to another aspect of the disclosure, a communication apparatus comprises a processing system configured to generate a packet that comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion and transmit the packet.
- According to another aspect of the disclosure, a computer-program product for communications comprises a machine-readable medium encoded with instructions executable to generate a packet that comprises a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion and transmit the packet.
- According to another aspect of the disclosure, a method of communication is provided. More specifically, a payload of a packet is divided into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes and information is inserted between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation. Thereafter, the packet is transmitted.
- According to another aspect of the disclosure, an apparatus for communication, comprises means for dividing a payload of a packet into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes, means for inserting information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation and means for transmitting the packet.
- According to another aspect of the disclosure, an apparatus for wireless communications comprises a processing system configured to divide a payload of a packet into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes, insert information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation and transmit the packet.
- According to another aspect of the disclosure, a computer-program product for communication comprises a machine-readable medium encoded with instructions executable to divide a payload of a packet into a plurality of data blocks, wherein each data block comprises Golay codes and data portions, and every data portion is between two Golay codes, insert information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation and transmit the packet.
- Although particular aspects are described herein, many variations and permutations of these aspects fall within the scope of the disclosure. Whereas some benefits and advantages of the preferred aspects are mentioned, the scope of the disclosure is not intended to be limited to particular benefits, uses, or objectives. Rather, aspects of the disclosure are intended to be broadly applicable to different wireless technologies, system configurations, networks, and transmission protocols, some of which are illustrated by way of example in the figures and in the following Detailed Description. The detailed description and drawings are merely illustrative of the disclosure rather than limiting, the scope of the disclosure being defined by the appended claims and equivalents thereof.
- Aspects according to the disclosure are understood with reference to the following figures.
-
FIG. 1 is a diagram of a wireless network configured in accordance with an aspect of the disclosure; -
FIG. 2 is a diagram of a superframe timing configured in accordance with an aspect of the disclosure that is used in the wireless network ofFIG. 1 ; -
FIG. 3 is a diagram of a superframe structure configured in accordance with an aspect of the disclosure that is used in the wireless network ofFIG. 1 ; -
FIG. 4 is a diagram of a frame/packet structure configured in accordance with an aspect of the disclosure that is used in the superframe structure ofFIG. 3 ; -
FIG. 5 is a diagram of an improved frame/packet structure that supports signaling for multiple header rates in accordance with an aspect of the disclosure; -
FIG. 6 is a diagram of multiple start frame delimiters that may be used in accordance with an aspect of the disclosure; -
FIG. 7 is a diagram of an improved frame/packet structure that supports signaling for superframe timing detection in accordance with an aspect of the disclosure; -
FIG. 8 is a flow chart illustrating a process for determining superframe timing information in accordance with an aspect of the disclosure; -
FIG. 9 is a diagram of an improved frame/packet structure that supports improved carrier estimation in accordance with an aspect of the disclosure; -
FIG. 10 is a diagram of a plurality of data blocks that may be used with reduced spectral lines in accordance with an aspect of the disclosure; -
FIG. 11 is a circuit diagram of a scrambler configured in accordance with an aspect of the disclosure; -
FIG. 12 is a diagram of an improved frame/packet structure configured for longer data blocks in accordance with an aspect of the disclosure; -
FIG. 13 is a circuit diagram of a Golay circuitry configured in accordance with an aspect of the disclosure; -
FIG. 14 is a block diagram of a start frame delimiter generator apparatus configured in accordance with an aspect of the disclosure; -
FIG. 15 is a block diagram of a timestamp generator apparatus configured in accordance with an aspect of the disclosure; and, -
FIG. 16 is a block diagram of a channel estimation sequence generator apparatus configured in accordance with an aspect of the disclosure. - In accordance with common practice the various features illustrated in the drawings may be simplified for clarity. Thus, the drawings may not depict all of the components of a given apparatus (e.g., device) or method. In addition, like reference numerals may be used to denote like features throughout the specification and figures.
- Various aspects of the disclosure are described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein are merely representative. Based on the teachings herein one skilled in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein.
- In the following description, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosure. It should be understood, however, that the particular aspects shown and described herein are not intended to limit the disclosure to any particular form, but rather, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure as defined by the claims.
- Several aspects of a
wireless network 100 will now be presented with reference toFIG. 1 , which is a network formed in a manner that is compatible with the IEEE 802.15.3c Personal Area Networks (PAN) standard and herein referred to as a piconet. Thenetwork 100 is a wireless ad hoc data communication system that allows a number of independent data devices such as a plurality of data devices (DEVs) 120 to communicate with each other. Networks with functionality similar to thenetwork 100 are also referred to as a basic service set (BSS), or independent basic service (IBSS) if the communication is between a pair of devices. - Each DEV of the plurality of
DEVs 120 is a device that implements a MAC and PHY interface to the wireless medium of thenetwork 100. A device with functionality similar to the devices in the plurality ofDEVs 120 may be referred to as an access terminal, a user terminal, a mobile station, a subscriber station, a station, a wireless device, a terminal, a node, or some other suitable terminology. The various concepts described throughout this disclosure are intended to apply to all suitable wireless nodes regardless of their specific nomenclature. - Under IEEE 802.15.3c, one DEV will assume the role of a coordinator of the piconet. This coordinating DEV is referred to as a PicoNet Coordinator (PNC) and is illustrated in
FIG. 1 as aPNC 110. Thus, the PNC includes the same device functionality of the plurality of other devices, but provides coordination for the network. For example, thePNC 110 provides services such as basic timing for thenetwork 100 using a beacon; and management of any Quality of Service (QoS) requirements, power-save modes, and network access control. A device with similar functionality as described for thePNC 110 in other systems may be referred to as an access point, a base station, a base transceiver station, a station, a terminal, a node, an access terminal acting as an access point, or some other suitable terminology. ThePNC 110 coordinates the communication between the various devices in thenetwork 100 using a structure referred as a superframe. Each superframe is bounded based on time by beacon periods. - The
PNC 110 may also be coupled to asystem controller 130 to communicate with other networks or other PNCs. -
FIG. 2 illustrates asuperframe 200 used for piconet timing in thenetwork 100. In general, a superframe is a basic time division structure containing a beacon period, a channel time allocation period and, optionally, a contention access period. The length of a superframe is also known as the beacon interval (BI). In thesuperframe 200, a beacon period (BP) 210 is provided during which a PNC such as thePNC 110 sends beacon frames, as further described herein. - A Contention Access Period (CAP) 220, is used to communicate commands and data either between the
PNC 110 and a DEV in the plurality ofDEVs 120 in thenetwork 100, or between any of the DEVs in the plurality ofDEVs 120 in thenetwork 100. The access method for theCAP 220 can be based on a slotted aloha or a carrier sense multiple access with collision avoidance (CSMA/CA) protocol. TheCAP 220 may not be included by thePNC 110 in each superframe. - A Channel Time Allocation Period (CTAP) 220, which is based on a Time Division Multiple Access (TDMA) protocol, is provided by the
PNC 110 to allocate time for the plurality ofDEVs 120 to use the channels in thenetwork 100. Specifically, the CTAP is divided into one or more time periods, referred to as Channel Time Allocations (CTAs), that are allocated by thePNC 110 to pairs of devices; one pair of devices per CTA. Thus, the access mechanism for CTAs is TDMA-based. -
FIG. 3 illustrates, as viewed from a data perspective, asuperframe structure 300 as employed by thenetwork 100. Thesuperframe structure 300 begins with abeacon period 302 in which a piconet controller such as thePNC 110 broadcasts various control parameters, including abeacon frame number 310 and asuperframe duration 312. This information is sent via one or more beacon packets (not shown). The transmission of a series of data packets 360 follows thebeacon period 302. These data packets may be transmitted by thePNC 110 or different devices that are members of the piconet. Each beacon period, such as thebeacon period 302, or any data packet, such as the data packet 360, is typically followed by a guard time (GT) 330. -
FIG. 4 is an example of aframe structure 400 that may be used for a single carrier, OFDM or common mode frame. As used herein, the term “frame” may also be referred to as a “packet”, and these two terms should be considered synonymous. - The
frame structure 400 includes apreamble 402, a header 440, and a packet payload 480. The common mode uses Golay codes for all three fields, i.e. for thepreamble 402, the header 440 and the packet payload 480. The common-mode signal uses Golay spreading codes with chip-level π/2-BPSK modulation to spread the data therein. The header 440, which is a physical layer convergence protocol (PLCP) conforming header, and the packet payload 480, which is a physical layer service data unit (PSDU), includes symbols spread with a Golay code pair of length-64. Various frame parameters, including, by way of example, but without limitation, the number of Golay-code repetitions and the Golay-code lengths, may be adapted in accordance with various aspects of theframe structure 400. In one aspect, Golay codes employed in the preamble may be selected from length-128 or length-256 Golay codes. Golay codes used for data spreading may comprise length-64 or length-128 Golay codes. - Referring back to
FIG. 4 , thepreamble 402 includes a packetsync sequence field 410, a start frame delimiter (SFD) field 420, and a channel-estimation sequence field 430. Thepreamble 402 may be shortened when higher data rates are used. For example, the default preamble length may be set to 36 Golay codes for the common mode, which is associated with a data rate on the order of 50 Mbps. For a data rate in the order of 1.5 Gbps data rate, thepreamble 402 may be shortened to 16 Golay codes, and for data rates around 3 Gbps, thepreamble 402 may be further shortened to 8 Golay codes. Thepreamble 402 may also be switched to a shorter preamble based upon either an implicit or explicit request from a device. - The packet
sync sequence field 410 is a repetition of ones spread by one of the length-128 complementary Golay codes (ai 128, bi 128) as represented by codes 412-1 to 412-n inFIG. 4 . The SFD field 420 comprises a specific code such as {−1} that is spread by one of the length-128 complementary Golay codes (ai 128, bi 128), as represented by a code 422 inFIG. 4 . TheCES field 430 may be spread using a pair of length-256 complementary Golay codes (ai 256, bi 256), as represented by codes 432 and 436, and may further comprise at least one cyclic prefix, as represented by 434-1 and 438-1, such as ai CP or bi CP, which are length-128 Golay codes, where CP is the Cyclic Prefix or Postfix. A cyclic postfix for each of the codes 432 and 436, such as ai CP or bi CP, respectively, as represented by 434-2 and 438-2, respectively, are length-128 Golay codes. - In one aspect, the header 440 employs approximately a rate one-half Reed Solomon (RS) coding, whereas the packet payload 480 employs a rate-0.937 RS coding, RS(255,239). The header 440 and the packet payload 480 may be binary or complex-valued, and spread using length-64 complementary Golay codes ai 64 and/or bi 64. Preferably, the header 440 should be transmitted in a more robust manner than the packet payload 480 to minimize packet error rate due to header error rate. For example, the header 440 can be provided with 4 dB to 6 dB higher coding gain than the data portion in the packet payload 480. The header rate may also be adapted in response to changes in the data rate. For example, for a range of data rates up to 1.5 Gbps, the header rate may be 400 Mbps. For data rates of 3 Gbps, the header rate may be 800 Mbps, and for a range of data rates up to 6 Gbps, the header rate may be set at 1.5 Gbps. A constant proportion of header rate may be maintained to a range of data rates. Thus, as the data rate is varied from one range to another, the header rate may be adjusted to maintain a constant ratio of header rate to data-rate range. It is important to communicate the change in header rate to each device in the plurality of
DEVs 120 in thenetwork 100. However, thecurrent frame structure 400 inFIG. 4 used by all modes (i.e., single carrier, OFDM and common modes), do not include an ability to do this. -
FIG. 5 illustrates animproved frame structure 500 that supports signaling for multiple header rates and multi PHY modes in accordance with an aspect of the disclosure. In this aspect, there may be up to four different header rates, each of which corresponds to a particular data rate or a range of data rates. Alternative aspects may provide for different numbers of header and data rates. Theframe structure 500 includes apreamble 502, aheader 540, and apacket payload 580. Theheader 540, andpacket payload 580 portions are configured in a similar fashion to the header 440 and the packet payload 480. Thepreamble 502 includes a packetsync sequence field 510, a start frame delimiter (SFD)code block 520, and a channel-estimation sequence field 530. - In the aspect illustrated in
FIG. 5 , theSFD code block 520 comprises threecodes SFD 1 522,SFD 2 524, andSFD 3 526. Further referring toFIG. 6 , in one aspect, a default header rate may be set to corresponds to anSFD code block 620 a, denoted by [−1 +1 +1], where the sign corresponds to the sign of the Golay code transmitted. For a first header rate (e.g., 400 Mbps), theSFD code block 520 is anSFD code block 620 a, denoted by [−1 +1 −1]. For a header rate of 800 Mbps, theSFD code block 520 is anSFD code block 620 c, denoted by [−1 −1 +1], and for a 1.5 Gbps header rate, theSFD code block 520 is anSFD code block 620 d, denoted by [−1 −1 −1]. In another aspect, a set of different SFD code blocks may be constructed using a complementary Golay codes, as indicated by a plurality of SFD code blocks 620 e to 620 h inFIG. 6 . In addition to just providing the header rate, the SFD patterns may also be used to provide other information, including differentiating between a single carrier and OFDM packets or differentiating between a beacon packet and a data packet. Furthermore, the SFD may be used to indicate a special type of packet used for beamforming. For example, theSFD pattern 620 a inFIG. 6 is assigned to beacon packets, theSFD patterns SFD patterns SFD pattern 620 h is assigned to beamforming training packets. Any device in the plurality ofDEVs 120 that is performing preamble detection will search for these SFD patterns. - In an aspect of the disclosure, the codes a in the packet
sync sequence field 510 may be scrambled by a cover code, such that each code a is multiplied by {+1} or {−1.} This may be done to reduce spectral lines that would otherwise result from code repetition in the packetsync sequence field 510. Furthermore, theSFD code block 520 can be encoded with the complementary code b, as illustrated and discussed previously inFIG. 5 andFIG. 6 . Thus, various combinations of a and b may be employed in theSFD code block 520. - As previously discussed, during the
beacon period 302, which is located at the beginning (i.e., time zero) of each superframe, one or more beacon packets will be sent by thePNC 110 to set the superframe duration, the CAP end time, the time allocations and to communicate management information for the piconet. When more than one beacon packet is transmitted by the PNC, beacon packet number one is transmitted at time zero and the remaining beacon packets contain information about the time offset from the beginning of the superframe. As beacon packets are critical for the proper functioning of all devices in thenetwork 100, any beacon packet to be sent during thebeacon period 302 is transmitted using a common-mode signal so that it can be understood by all devices. Further, no device can transmit until it has synchronized itself with the network. Thus, all devices in the plurality ofDEVs 120 must attempt to determine whether an existing network exists by detecting the beacon and locating the beginning of a superframe. - Each device in the
wireless network 100, upon start-up, searches for the superframe start time by locking to thebeacon period 302. Because the same Golay code is used for spreading the preambles for both beacon packets and data packets, whether each received segment is a beacon packet or a data packet is determined by decoding the header 440. However, this can be a problem for low-power devices, especially when long superframes (e.g., 65 ms long) are employed, since the device has to try to decode every packet for up to 20 ms before finding the beacon period. Furthermore, some data packets may employ the same spreading and protection for the header 440 as thebeacon 302, and thus will pass the CRC. -
FIG. 7 illustrates animproved frame structure 700 that supports time stamping and superframe timing information communication. In one aspect, theframe structure 700 includes apreamble 702, aheader 740, and apacket payload 780. Thepreamble 702 andpacket payload 780 portions are configured in a similar fashion to thepreamble 402 and the packet payload 480 of theframe structure 400 ofFIG. 4 . Theframe structure 700 further includes atime stamp 742 in theheader 740 that provides improved communication of the timing information of the superframe being transmitted. Thetime stamp 742 may be configured to include information to allow any device, once the device has received and decoded thetime stamp 742, to determine one or more of the following pieces of information in the following list, which is presented as examples and is not to be limiting: location information of the transmitted frame within the superframe, the superframe length, the start of the superframe, the end of the superframe, the location of the beacon and a location of the CAP. Collectively, the list of information is referred to herein as the superframe timing information. Thus, when a device in the plurality ofDEVs 120 desires to locate superframe timing information, it can capture any frame and, upon decoding the time stamp in the frame, will be able to determine superframe timing information. Thetime stamp 742 can thus assist the device to locate the beacon period. Preferably, thetime stamp 742 will be positioned as the first field in theheader field 740 so the device can avoid having to decode the entire header and, instead, only decode the portion of theheader 740 it needs to determined the superframe timing information it needs. - Some packets are transmitted without a header (for example, some beamforming packets may be transmitted without headers and payloads), and in this case then the
SFD code block 520 may be configured to identify these packets so that the receiving device would know that these packets contain no timing information. - In one aspect of the disclosure, in cases where the same preamble may be used by devices supporting both single carrier and OFDM modes. Thus, the
SFD code block 520 can use different sets of SFD patterns that are assigned to single carrier and OFDM modes in order for a receiving device to differentiate between single carrier and OFDM packets. - In an aspect of the disclosure, the
time stamp 742 can be compressed to reduce overhead if needed. For example, an eight-bit time stamp may be used from which the location of the beacon can be computed, but with less resolution. - Once the device locates the beacon, it may go into a sleep mode to save power and awaken just before the beacon period to detect, for example, the header rate. Thus, when a device in the plurality of
DEVs 120 needs to determine the header rate, it can acquire that information by timing the power-up or awakening at a sufficient time before the beacon period. -
FIG. 8 illustrates a superframe timinginformation acquisition process 800 that may be performed by a device in the plurality ofDEVs 120 to acquire superframe timing information in one aspect of the disclosure. Instep 802, DEV will initialize and prepare to perform wireless communication with thenetwork 100. Instep 804, the DEV will try to detect the preamble of a beacon frame or data frame. Assuming the detection is successful, the DEV will decode the header, or at least timestamp portion of the header instep 806. Then, instep 808, the DEV can determine superframe timing information from the decoded timestamp. - Once the superframe timing information has been determined by the DEV, it will have the option of using it in
step 810. In one aspect of the disclosure, as discussed previously herein, the DEV may decide to enter into a low-power or sleep mode until the next beacon period to acquire the full information about the superframe being transmitted by thePNC 110. For example, the DEV may put itself to sleep for a predetermined period, such as a period of time sufficient for the current superframe to end. As another example, the DEV can enter into the sleep mode for more than one beacon period, and periodically awaken to acquire superframe timing information. Although there may be certain requirements for a device such as the DEV to operate within guidelines so as not to miss more than a predetermined number of beacons for concerns of losing synchronization, the DEV in this scenario can still maintain timing synchronization because of its use of the timestamp. - In another aspect, if DEV detects the timestamp and finds that the superframe is in the CAP phase, then the DEV can attempt to join the
network 100 without having to wait for the beacon and CAP phase. - In another aspect, the DEV may detect whether a particular channel in the
network 100 is busy without having to wait to detect a beacon. In this aspect, once the DEV detects a timestamp, it will assume that channel is busy and the move to next channel. - As already discussed above, the timestamp facilitates beacon and superframe timing detection because DEV does not have to decode every packet to determine if a particular packet is a beacon packet. At the most, the DEV just has to decode one timestamp successfully. Thus, the DEV does not have to decode completely the header and possibly data to determine if the packet is a beacon packet or not.
- The timestamp can also be used to improve acquisition of signal and joining of the network by the plurality of
DEVs 120. For example, assume a DEV 120-2 is far enough away from thePNC 110 not to have good detection of the beacon transmitted by thePNC 110. However, also assume the DEV 120-1 is closer to thePNC 110 but also close to the DEV 120-2 and can reliably detect the beacon from thePNC 110. Because all devices will include timestamp information in their transmissions and the DEV 120-2 can hear the transmissions from DEV 120-1, the DEV 120-2 will have a better idea of the beacon location and can alter its operation to improve its chances of receiving the beacon. For example, the DEV 120-2 can lower its preamble detection threshold during the expected time of beacon transmission from thePNC 110, which is a function of Signal-to-Noise Ratio (SNR) or Signal-to-Noise/Interference Ratio (SNIR), because it is more certain that a detection will not be a false positive. - In some aspects of the disclosure, preambles for different piconets operating in the same frequency band may employ cover sequences that provide for orthogonality in time and/or frequency. In one aspect, a first piconet controller PNC1 uses a first Golay code a1281 of length 128, a second piconet controller PNC2 uses a1282, and a third piconet controller PNC3 uses a1283. The preamble is formed from 8 repetitions of each Golay code multiplied by an orthogonal covering code, such as shown in the following case:
-
PNC1 transmits: +a1+a1+a1+a1+a1+a1+a1+a1(cover code[1 1 1 1 1]) -
PNC2 transmits: +a2−a2+a2−a2+a2−a2+a2−a2(cover code[1 −1 1 −1]) -
PNC3 transmits: +a3+a3−a3−a3+a3+a3−a3−a3(cover code([1 1 −1 −1]) - Thus, even though the system is asynchronous, there is still orthogonality at any time shift.
- In this case, these are the only three binary codes that are periodically orthogonal. For example, periodic orthogonality means that if a first covering code is repeated, such as:
-
1 −1 1 −1 1 −1 1 −1 1 −1 . . . , - and it is matched-filtered to a second, orthogonal covering code, the result is zero everywhere except at the leading and trailing edges of the repeated code.
- In some aspects of the disclosure, non-binary cover codes may be provided.
- For example, complex covering codes of
length 4 are shown as follows: -
cover1=ifft([1 0 0 0])=[1 1 1 1] -
cover2=ifft([0 1 0 0])=[1 j −1 −j] -
cover3=ifft([0 0 1 0])=[1 −1 −1] -
cover4=ifft([0 0 0 1])=[1−j −1 j] - These codes may be used to multiply a particular Golay code (e.g., a(1)) as follows [a1.cover1(1) a1.cover1(2) a1.cover1(3) a1.cover1(4)]. The Fast Fourier Transform (FFT) of this sequence is nonzero for every fourth subcarrier. If a1 is of length 128 and the FFT length is 512 (numbered 0:511), then cover1 produces
non-zero subcarriers 0, 4, 8, . . . . With cover2, onlysubcarriers non-zero subcarriers 2, 6, 10 . . . , and cover4 producessubcarriers - During the beacon period, beacons with almost omni-directional antenna patterns (Quasi-omni beacons) are first transmitted. Directional beacons (i.e., beacons transmitted with some antenna gain in some direction(s)) may be transmitted during the beacon period or in the CTAP between two devices.
- In one embodiment of the disclosure, a combination of Golay-code length and number of repetitions is adapted to different antenna gains. For example, for an antenna gain of 0-3 dB, the beacons are transmitted using the common mode with a default preamble comprising 32 repetitions of a length-128 Golay code. For antenna gains of 3-6 dB, the beacons employ a shortened preamble of 16 repetitions of the same Golay code. For antenna gains of 6-9 dB, the beacons use a shortened preamble of 8 repetitions of the Golay code. For antenna gains of 9 dB and above, the beacons employ a shortened preamble of 4 repetitions of the Golay code. Furthermore, in some embodiments, header and/or data spreading factors may be scaled relative to the antenna gain.
-
FIG. 9 illustrates aframe structure 900 in accordance with an aspect of the disclosure. In one aspect, theframe structure 900 includes apreamble 902, aheader 940, and apacket payload 980. Thepreamble 902 andpacket payload 980 portions are configured in a similar fashion to thepreamble 902 and the packet payload 480 of theframe structure 900 ofFIG. 9 . The data portion of the frame, which may include theheader 940 and includes thepacket payload 980 is partitioned into a plurality of blocks 950-1 to 950-n, and each block 950-1 to 950-n is further partitioned into sub-blocks, such as sub-blocks 952-1 to 952-n. Each sub-block 952-1 to 952-n is preceded by a known Golay sequence of length L, such as known Golay sequences 954-1 to 954-n, which should be typically longer than the multipath delay spread. Further, the last data portion 956-n is followed by a known Golay sequence 954-[n+1]. In one aspect, all known Golay sequences within a particular data block are identical. The known Golay sequences functions as a cyclic prefix if a frequency domain equalizer is used. Furthermore, it can be used for timing, frequency, and channel tracking. Each data block 950-1 to 950-n is followed by a pilot channel estimation sequence (PCES) 960 having a complementary set of Golay codes 964-1 and 968-1 each having a CP 962-1 and 966-2, respectively. ThePCES 960 can be used to reacquire the channel if needed, and the repetition period for thePCES 960 can be changed to reduce overhead. The PCES period can, for example, be encoded in theheader 940. - In order for the known Golay sequences 954-1 to 954-n to be used as a CP in a frequency-domain equalizer (or in other equalizer types), the same L-length Golay sequence (aL) needs to be used. However, a repetition of the known Golay sequence introduces spectral lines. In order to mitigate spectral lines, each data block uses a different known Golay sequence, such as shown in
FIG. 10 . For example, a pair of Golay codes (aL,bL) may be employed, wherein aL and bL denotes a pair of complementary Golay sequences of length L, or a shorter length K<L protected by its own short cyclic prefix. For example, for L=20, a Golay code-length of 16 may be used with the last 4 samples repeated in the beginning. Each data block may use aL, −aL, bL, or −bL. Ascrambler 1100, such as shown inFIG. 11 , may be used for selecting Golay codes aL, −aL, bL, and −bL. In one aspect, thescrambler 1100 may be implemented as a feedback-shift register. Thescrambler 1100 may be used to choose the Golay codes for each data block. - In another embodiment of the disclosure, longer data blocks may be employed, and a
frame structure 1200 shown inFIG. 12 may be employed. In this example, each data block employs one of the four Golay-code options aL, −aL, bL, and −bL for a portion of the data block, and the codes are changed for each portion. For example, different block portions 1250-1 to 1250-5 of adata block 1202 use different Golay codes (e.g., Golay code 1254-1-1 forblock portion 2 1250-1 versus Golay code 1254-1-2 forblock portion 2 1250-2). - A known sequence can be used both before and after equalization. For example, techniques for using a known sequence before and after equalization for timing, frequency and channel tracking are well known in the art. However, aspects of the disclosure may provide for further uses of known Golay sequences. After equalization, there is a noisy estimate of the known transmitted Golay sequence. By correlating the estimated noisy version with the original clean version of the Golay sequence, the residual multipath can be estimated and used for time-domain equalization with a very simple short equalizer (e.g., a two-taps equalizer).
-
FIG. 13 is a block diagram of a Golay-code circuitry 1300 that may be employed as a Golay code generator or matched filter in some aspects of the disclosure. The Golay-code circuitry 1300 comprises a sequence of delay elements 1302-1 to 1302-M, a sequence of adaptable seed vector insertion elements 1330-1 to 1330-M, a first set of combiners 1310-1 to 1310-M, and a second set of combiners 1320-1 to 1320-M configured for combining delayed signals with signals multiplied by the seed vector. - In one aspect of the disclosure, the following set of three sequences may be used for the preamble for spatial and frequency reuse to minimize interference between piconets operating in the same frequency band.
-
a or b ab 0 1 1 Delay and Seed Vectors D1 64 16 2 32 8 1 4 D2 64 16 2 32 8 1 4 D3 64 16 2 32 8 1 4 W1 1 1 −1 1 −1 1 1 W2 −1 1 −1 1 −1 1 −1 W3 1 1 −1 −1 −1 −1 1 Sequences in Hexadecimal s1 3663FAAFFA50369CC99CFAAF05AF369C s2 C99C055005AFC963C99CFAAF05AF369C s3 6C39A0F55FF5933993C6A0F5A00A9339 - The Delay vectors are denoted by D1, D2, and D3, and corresponding seed vectors are denoted by W1, W2, and W3. The first sequence employs Golay code a, and the second and third sequences are type-b sequences. The binary sequences (s1, s2, and s3) are provided in hexadecimal format. These sequences are optimized to have minimum sidelobe levels and minimum cross-correlation.
- Common mode data sequences may employ the following set of Golay complementary codes.
-
Delay and Seed Vectors D1 16 32 4 8 2 1 D2 16 32 4 8 2 1 D3 16 32 4 8 2 1 W1 −1 1 −1 1 1 1 W2 −1 −1 −1 1 −1 1 W3 1 1 −1 1 −1 1 Sequences in Hexadecimal a1 2DEE2DEE22E1DD1E b1 78BB78BB77B4884B a2 E122E12211D2EE2D b2 B477B4774487BB78 a3 E1221EDDEE2DEE2D b3 B4774B88BB78BB78 - The Golay sequences a and b are of length 64. Each
symbol carriers 2 bits per symbol. For example, when the 2 bits are “00,” a is transmitted. When the bits are “01,”−a is transmitted. When the bits correspond to “10,” b is transmitted; and for the bit combination “11”, −b is transmitted. - Three pairs of complementary Golay codes are employed for frequency reuse, wherein one pair is used per piconet. These pairs are provided selected to have low cross-correlation between each other and with the preamble. These codes can be used as well as the known sequences before each sub-burst
- In one aspect of the disclosure, the following length-16 and length-8 codes may be used as spreading codes and/or as the known cyclic prefix before each sub-burst.
-
Delay and Seed Vectors For length 16 sequences D1 4 2 8 1 D2 4 8 2 1 D3 4 2 8 1 W1 1 1 −1 1 W2 1 1 −1 1 W3 −1 1 −1 1 Length 16 Sequences in Hexadecimal a1 56CF b1 039A a2 1EDD b2 4B88 a3 A63F b3 F36A Delay and Seed Vectors For length 8 sequences D1 4 2 1 D2 2 1 4 D3 2 4 1 W1 1 1 1 W2 1 1 1 W3 −1 1 1 Length 8 Sequences in Hexadecimal a1 DE b1 8B a2 BE b2 4E a3 AC b3 F9 - In various aspects of the disclosure, the following sequences of length 128 shown in hexadecimal and generated from the following delay and seed vectors may be provided as the cyclic prefix or for the PCES field.
-
Delay and Seed Vectors D1 64 32 16 4 2 8 1 D2 64 32 16 4 2 8 1 D3 64 32 16 4 2 8 1 W1 1 1 1 1 1 1 1 W2 1 −1 −1 −1 1 −1 1 W3 −1 −1 1 1 −1 −1 1 Sequences in Hexadecimal a1 593F5630593FA9CFA6C0A9CF593FA9CF b1 0C6A03650C6AFC9AF395FC9A0C6AFC9A a2 56CFA63FA930A63FA93059C0A930A63F b2 039AF36AFC65F36AFC650C95FC65F36A a3 950C9A036AF39A03950C9A03950C65FC b3 C059CF563FA6CF56C059CF56C05930A9 - In one aspect of the disclosure, the following sequences of length-256 and 512 may be used in the Pilot Channel Estimation Sequences (PCES). These sequences have low cross-correlation with each other and with the preamble.
-
Delay and Seed Vectors for length-256 sequences D1 128 64 32 16 4 2 8 1 D2 128 64 32 16 4 2 8 1 D3 128 64 32 16 4 2 8 1 W1 −1 1 1 1 1 1 1 1 W2 −1 −1 −1 1 1 1 1 1 W3 1 1 −1 1 −1 −1 1 1 Length-256 Sequences in Hexadecimal a1 593F5630593FA9CF593F5630A6C05630593F5630593FA9CFA6C0A9CF593FA9CF b1 0C6A03650C6AFC9A0C6A0365F39503650C6A03650C6AFC9AF395FC9A0C6AFC9A a2 593F5630A6C05630A6C0A9CFA6C05630593F5630A6C05630593F5630593FA9CF b2 0C6A0365F3950365F395FC9AF39503650C6A0365F39503650C6A03650C6AFC9A a3 9AFC95F3650395F39AFC95F39AFC6A0C65036A0C9AFC6A0C9AFC95F39AFC6A0C b3 CFA9C0A63056C0A6CFA9C0A6CFA93F5930563F59CFA93F59CFA9C0A6CFA93F59 -
Delay and Seed Vectors for length-512 sequences D1 256 128 64 32 16 4 2 8 1 D2 256 128 64 32 16 4 2 8 1 D3 256 128 64 32 16 4 2 8 1 W1 1 1 1 1 1 1 1 1 1 W2 −1 1 1 1 −1 −1 −1 1 1 W3 −1 −1 −1 1 −1 1 1 −1 1 Length-512 Sequences in Hexadecimal a1 593F5630593FA9CF593F5630A6C05630593F5630593FA9CFA6C0A9CF593FA 9CFA6C0A9CFA6C05630A6C0A9CF593FA9CF593F5630593FA9CFA6C0A9C F593FA9CF b1 0C6A03650C6AFC9A0C6A0365F39503650C6A03650C6AFC9AF395FC9A0C6 AFC9AF395FC9AF3950365F395FC9A0C6AFC9A0C6A03650C6AFC9AF395FC 9A0C6AFC9A a2 9AFC6A0C9AFC95F39AFC6A0C65036A0C9AFC6A0C9AFC95F3650395F39A FC95F39AFC6A0C9AFC95F39AFC6A0C65036A0C650395F365036A0C9AFC6 A0C65036A0C b2 CFA93F59CFA9C0A6CFA93F5930563F59CFA93F59CFA9C0A63056C0A6CFA 9C0A6CFA93F59CFA9C0A6CFA93F5930563F593056C0A630563F59CFA93F5 930563F59 a3 A63F56CFA63FA93059C0A930A63FA93059C0A93059C056CF59C0A930A63F A930A63F56CFA63FA93059C0A930A63FA930A63F56CFA63FA930A63F56C F59C056CF b3 F36A039AF36AFC650C95FC65F36AFC650C95FC650C95039A0C95FC65F36A FC65F36A039AF36AFC650C95FC65F36AFC65F36A039AF36AFC65F36A039 A0C95039A -
FIG. 14 illustrates a start framedelimiter generation apparatus 1400 that may be used in various aspects of the disclosure, with atimestamp generation module 1402 for generating a packet that includes a first portion and a second portion separated by a delimiter, wherein the delimiter is further used to signal a characteristic of the second portion; and apacket transmission module 1404 for transmitting the packet. -
FIG. 15 illustrates atimestamp generation apparatus 1500 that may be used in various aspects of the disclosure, with atimestamp generation module 1502 for generating a packet having a header that includes location information of the packet with respect to a beacon; and atimestamp transmission module 1504 for transmitting the packet, wherein the packet and the beacon are transmitted within a superframe. -
FIG. 16 illustrates a channel estimationsequence generation apparatus 1600 that may be used in various aspects of the disclosure, with a datablock generator module 1602 for dividing a payload of a packet into a plurality of data blocks, wherein each data block includes Golay codes and data portions, and every data portion is between two Golay codes; a channel estimation sequence generation andinsertion module 1604 for inserting information between data blocks of the plurality of data blocks, said information enabling at least one of time, channel and frequency estimation; and apacket transmission module 1606 for transmitting the packet. - Various aspects described herein may be implemented as a method, apparatus, or article of manufacture using standard programming and/or engineering techniques. The term “article of manufacture” as used herein is intended to encompass a computer program accessible from any computer-readable device, carrier, or media. For example, computer readable media may include, but are not limited to, magnetic storage devices, optical disks, digital versatile disk, smart cards, and flash memory devices.
- The disclosure is not intended to be limited to the preferred aspects. Furthermore, those skilled in the art should recognize that the method and apparatus aspects described herein may be implemented in a variety of ways, including implementations in hardware, software, firmware, or various combinations thereof. Examples of such hardware may include ASICs, Field Programmable Gate Arrays, general-purpose processors, DSPs, and/or other circuitry. Software and/or firmware implementations of the disclosure may be implemented via any combination of programming languages, including Java, C, C++, Matlab™, Verilog, VHDL, and/or processor specific machine and assembly languages.
- Those of skill would further appreciate that the various illustrative logical blocks, modules, processors, means, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which may be designed using source coding or some other technique), various forms of program or design code incorporating instructions (which may be referred to herein, for convenience, as “software” or a “software module”), or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.
- The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented within or performed by an integrated circuit (“IC”), an access terminal, or an access point. The IC may comprise a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, electrical components, optical components, mechanical components, or any combination thereof designed to perform the functions described herein, and may execute codes or instructions that reside within the IC, outside of the IC, or both. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
- The method and system aspects described herein merely illustrate particular aspects of the disclosure. It should be appreciated that those skilled in the art will be able to devise various arrangements, which, although not explicitly described or shown herein, embody the principles of the disclosure and are included within its scope. Furthermore, all examples and conditional language recited herein are intended to be only for pedagogical purposes to aid the reader in understanding the principles of the disclosure. This disclosure and its associated references are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and aspects of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future, i.e., any elements developed that perform the same function, regardless of structure.
- It should be appreciated by those skilled in the art that the block diagrams herein represent conceptual views of illustrative circuitry, algorithms, and functional steps embodying principles of the disclosure. Similarly, it should be appreciated that any flow charts, flow diagrams, signal diagrams, system diagrams, codes, and the like represent various processes that may be substantially represented in computer-readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.
Claims (48)
1. A method of communication, comprising:
generating a packet having a header that comprises location information of the packet with respect to a beacon; and
transmitting the packet, wherein the packet and the beacon are transmitted within a superframe.
2. The method of claim 1 , wherein the location information indicates a time offset to a location within the superframe.
3. The method of claim 1 , wherein the location information comprises a time offset to an end of the superframe.
4. The method of claim 1 , wherein the location information comprises a time offset to a start of the superframe.
5. The method of claim 1 , wherein the location information comprises duration information for the superframe.
6. The method of claim 1 , wherein the packet and the beacon are transmitted by a single device.
7. The method of claim 6 , wherein the single device is a PNC.
8. The method of claim 1 , wherein the packet is generated and transmitted by a first device and the beacon is transmitted by a second device.
9. The method of claim 8 , wherein the second device is configured as a PNC.
10. A communication apparatus, comprising:
means for generating a packet having a header that comprises location information of the packet with respect to a beacon; and
means for transmitting the packet, wherein the packet and the beacon are transmitted within a superframe.
11. The communication apparatus of claim 10 , wherein the location information indicates a time offset to a location within the superframe
12. The communication apparatus of claim 10 , wherein the location information comprises a time offset to an end of the superframe.
13. The communication apparatus of claim 10 , wherein the location information comprises a time offset to a start of the superframe.
14. The communication apparatus of claim 10 , wherein the location information comprises duration information for the superframe.
15. The communication apparatus of claim 10 , wherein the packet and beacon are transmitted by the apparatus.
16. The communication apparatus of claim 15 , wherein the apparatus is a PNC.
17. The communication apparatus of claim 10 , wherein packet is generated and transmitted by the apparatus and the beacon is transmitted by a second apparatus.
18. The communication apparatus of claim 17 , wherein the second apparatus is configured as a PNC.
19. An apparatus for communications comprising:
a processing system configured to:
generate a packet having a header that comprises location information of the packet with respect to a beacon; and
transmit the packet, wherein the packet and the beacon are transmitted within a superframe.
20. The apparatus of claim 19 , wherein the location information indicates a time offset to a location within the superframe
21. The apparatus of claim 19 , wherein the location information comprises a time offset to an end of the superframe.
22. The apparatus of claim 19 , wherein the location information comprises a time offset to a start of the superframe.
23. The apparatus of claim 19 , wherein the location information comprises duration information for the superframe.
24. The apparatus of claim 19 , wherein the packet and beacon are transmitted by the apparatus.
25. The apparatus of claim 24 , wherein the apparatus is a PNC.
26. The apparatus of claim 19 , wherein packet is generated and transmitted by the apparatus and the beacon is transmitted by a second apparatus.
27. The apparatus of claim 26 , wherein the second apparatus is configured as a PNC.
28. A computer-program product for wireless communications comprising:
a machine-readable medium encoded with instructions executable to:
generate a packet having a header that comprises location information of the packet with respect to a beacon; and
transmit the packet, wherein the packet and the beacon are transmitted within a superframe.
29. A piconet coordinator comprising:
an antenna;
a packet generator configured to generate a packet having a header that comprises location information of the packet with respect to a beacon being transmitted; and
a transmitter configured to transmit, via the antenna, the packet, wherein the packet and the beacon are transmitted within a superframe.
30. A method of communication, comprising:
receiving a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe; and
using the location information to determine a location within the superframe.
31. The method of claim 30 , wherein the location comprises one of an end of the superframe, a start of another superframe, a start of another beacon and a location of a CAP.
32. The method of claim 30 , further comprising entering into a power-saving mode based on the determination.
33. The method of claim 30 , further comprising entering into a power saving mode for a time period until the location is reached.
34. The method of claim 30 , further comprising entering into a power saving mode for a time period that was calculated based on the location information.
35. The method of claim 34 , wherein the time period ends before a next beacon period begins.
36. A communication apparatus, comprising:
means for receiving a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe; and
means for determining a location within the superframe.
37. The communication apparatus of claim 36 , wherein the location comprises one of an end of the superframe, a start of another superframe, a start of another beacon and a location of a CAP.
38. The communication apparatus of claim 36 , further comprising means for entering into a power-saving mode based on the determination.
39. The communication apparatus of claim 36 , further comprising means for entering into a power saving mode for a time period until the location is reached.
40. The communication apparatus of claim 39 , wherein the predetermined time period ends before a next beacon period begins.
41. An apparatus for communications comprising:
a processing system configured to:
receive a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe; and
determine a location within the superframe
42. The apparatus of claim 41 , wherein the location comprises at least one of an end of the superframe, a start of another superframe, a start of another beacon and a location of a CAP.
43. The apparatus of claim 41 , further comprising entering into a power-saving mode based on the determination.
44. The apparatus of claim 41 , further comprising entering into a power saving mode for a time period until the location is reached.
45. The apparatus of claim 41 , further comprising entering into a power saving mode for a predetermined time period.
46. The apparatus of claim 45 , wherein the predetermined time period ends before a next beacon period begins.
47. A computer-program product for wireless communications comprising:
a machine-readable medium encoded with instructions executable to:
receive a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe; and
determine a location within the superframe.
48. A wireless device (DEV) comprising:
a receiver configured to receive a packet having a header that comprises a location information of the packet with respect to a beacon, wherein the packet and the beacon are transmitted within a superframe; and
a location determination module that uses the location information to determine a location within the superframe.
Priority Applications (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/262,159 US20090109955A1 (en) | 2007-10-31 | 2008-10-30 | Method and apparatus for improved frame synchronization in a wireless communication network |
JP2010532300A JP5280456B2 (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
PCT/US2008/082117 WO2009059226A2 (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
KR1020127008176A KR20120043143A (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
TW097142248A TW200929961A (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
CN200880114343A CN101842997A (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
EP08843942.7A EP2223435B1 (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
KR1020107012020A KR101358900B1 (en) | 2007-10-31 | 2008-10-31 | Method and apparatus for improved frame synchronization in a wireless communication network |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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US98429607P | 2007-10-31 | 2007-10-31 | |
US12/262,159 US20090109955A1 (en) | 2007-10-31 | 2008-10-30 | Method and apparatus for improved frame synchronization in a wireless communication network |
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Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090109945A1 (en) * | 2007-10-31 | 2009-04-30 | Qualcomm Incorporated | Method and apparatus for improved data demodulation in a wireless communication network |
US20100111229A1 (en) * | 2008-08-08 | 2010-05-06 | Assaf Kasher | Method and apparatus of generating packet preamble |
US20100157907A1 (en) * | 2007-10-31 | 2010-06-24 | Qualcomm Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
US20100226344A1 (en) * | 2008-03-12 | 2010-09-09 | Saishankar Nandagopalan | Method and System for Scheduling Multiple Concurrent Transmissions During a Contention Access Period in a Wireless Communications Network |
US20100290451A1 (en) * | 2003-10-24 | 2010-11-18 | Broadcom Corporation | Synchronized UWB piconets for SOP (Simultaneously Operating Piconet) performance |
US20100309832A1 (en) * | 2009-06-03 | 2010-12-09 | Kennan Laudel | Partial dmm reception to reduce standby power |
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US20110243267A1 (en) * | 2010-03-31 | 2011-10-06 | Korea Electronics Technology Institute | Magnetic field communication method for managing node with low power consumption |
US20120207181A1 (en) * | 2008-05-15 | 2012-08-16 | Hongyuan Zhang | Efficient physical layer preamble format |
US9961653B2 (en) | 2011-08-19 | 2018-05-01 | Qualcomm Incorporated | Beacons for wireless communication |
US20210037491A1 (en) * | 2009-08-31 | 2021-02-04 | Texas Instruments Incorporated | Short and long training fields |
US11057252B2 (en) * | 2016-08-10 | 2021-07-06 | Huawei Technologies Co., Ltd. | Common synchronization signal for sliced OFDM transmission |
Families Citing this family (66)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8149811B2 (en) | 2007-07-18 | 2012-04-03 | Marvell World Trade Ltd. | Wireless network with simultaneous uplink transmission of independent data from multiple client stations |
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US7916081B2 (en) | 2007-12-19 | 2011-03-29 | Qualcomm Incorporated | Beamforming in MIMO systems |
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US8982889B2 (en) | 2008-07-18 | 2015-03-17 | Marvell World Trade Ltd. | Preamble designs for sub-1GHz frequency bands |
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US8184052B1 (en) | 2008-09-24 | 2012-05-22 | Marvell International Ltd. | Digital beamforming scheme for phased-array antennas |
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US8335167B1 (en) | 2009-02-02 | 2012-12-18 | Marvell International Ltd. | Refining beamforming techniques for phased-array antennas |
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KR101721615B1 (en) | 2009-04-17 | 2017-03-30 | 마벨 월드 트레이드 리미티드 | Segmented beamforming |
WO2010143167A2 (en) | 2009-06-12 | 2010-12-16 | Coppergate Communications Ltd. | Network-specific powerline transmissions |
US9077594B2 (en) | 2009-07-23 | 2015-07-07 | Marvell International Ltd. | Coexistence of a normal-rate physical layer and a low-rate physical layer in a wireless network |
US8265050B2 (en) * | 2009-08-07 | 2012-09-11 | Time Warner Cable, Inc. | System and method for sharing a payload among mobile devices in a wireless network |
US20110064161A1 (en) * | 2009-09-14 | 2011-03-17 | Electronics And Telecommunications Research Institute | Frequency selective transmission apparatus |
US9219576B2 (en) | 2009-09-18 | 2015-12-22 | Marvell World Trade Ltd. | Short packet for use in beamforming |
US20110075603A1 (en) * | 2009-09-30 | 2011-03-31 | Alaa Muqattash | Medium allocation in a distributed network |
US8891592B1 (en) | 2009-10-16 | 2014-11-18 | Marvell International Ltd. | Control physical layer (PHY) data unit |
KR101046991B1 (en) | 2009-12-10 | 2011-07-07 | 대구대학교 산학협력단 | How to Improve Time Synchronization Performance of Superframe Structure |
US8933131B2 (en) | 2010-01-12 | 2015-01-13 | The Procter & Gamble Company | Intermediates and surfactants useful in household cleaning and personal care compositions, and methods of making the same |
JP5388127B2 (en) * | 2010-01-15 | 2014-01-15 | 独立行政法人情報通信研究機構 | Wireless communication method and system, wireless communication apparatus, and program |
US9021341B1 (en) | 2010-06-16 | 2015-04-28 | Marvell International Ltd. | LDPC coding in a communication system |
US9178651B2 (en) | 2010-09-29 | 2015-11-03 | Marvell World Trade Ltd. | Stream parsing in a communication system |
US8804617B2 (en) * | 2010-12-21 | 2014-08-12 | Industrial Technology Research Institute | Wireless transmission method, base station, relay station and mobile station using the same |
EP2668736B1 (en) | 2011-01-28 | 2018-04-25 | Marvell World Trade Ltd. | Physical layer frame format for long range wlan |
EP3327965B1 (en) | 2011-02-04 | 2019-09-25 | Marvell World Trade Ltd. | Control mode phy for wlan |
US9178745B2 (en) | 2011-02-04 | 2015-11-03 | Marvell World Trade Ltd. | Control mode PHY for WLAN |
EP2674002B1 (en) | 2011-02-08 | 2018-06-06 | Marvell World Trade Ltd. | Wlan channel allocation |
US9642171B2 (en) * | 2011-07-10 | 2017-05-02 | Qualcomm Incorporated | Systems and methods for low-overhead wireless beacons having compressed network identifiers |
US9253808B2 (en) | 2011-07-10 | 2016-02-02 | Qualcomm Incorporated | Systems and methods for low-overhead wireless beacons having next full beacon indications |
US9232473B2 (en) | 2011-07-10 | 2016-01-05 | Qualcomm Incorporated | Systems and methods for low-overhead wireless beacon timing |
US9167609B2 (en) * | 2011-07-10 | 2015-10-20 | Qualcomm Incorporated | Systems and methods for low-overhead wireless beacon timing |
CN103765973B (en) | 2011-08-29 | 2017-11-10 | 马维尔国际贸易有限公司 | Normal speed physical layer and low rate physical layer coexisting in the wireless network |
WO2013104999A2 (en) | 2012-01-13 | 2013-07-18 | Marvell World Trade Ltd. | Data unit format for single user beamforming in long-range wireless local area networks (wlans) |
KR20200024960A (en) | 2012-02-07 | 2020-03-09 | 마벨 월드 트레이드 리미티드 | Pilot sequence design for long range wlan |
US9420524B1 (en) | 2013-01-15 | 2016-08-16 | Marvell International Ltd. | Adaptive multimodal provisioning for wireless sensors |
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US8842571B1 (en) | 2013-02-22 | 2014-09-23 | Marvell International Ltd. | Method and apparatus for determining a time of arrival of a data unit |
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EP3061219B1 (en) | 2013-10-25 | 2020-04-08 | Marvell World Trade Ltd. | Range extension mode for wifi |
US10194006B2 (en) | 2013-10-25 | 2019-01-29 | Marvell World Trade Ltd. | Physical layer frame format for WLAN |
US10218822B2 (en) | 2013-10-25 | 2019-02-26 | Marvell World Trade Ltd. | Physical layer frame format for WLAN |
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US11855818B1 (en) | 2014-04-30 | 2023-12-26 | Marvell Asia Pte Ltd | Adaptive orthogonal frequency division multiplexing (OFDM) numerology in a wireless communication network |
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US10021695B2 (en) | 2015-04-14 | 2018-07-10 | Qualcomm Incorporated | Apparatus and method for generating and transmitting data frames |
US10382598B1 (en) | 2015-05-01 | 2019-08-13 | Marvell International Ltd. | Physical layer frame format for WLAN |
US10181966B1 (en) | 2015-05-01 | 2019-01-15 | Marvell International Ltd. | WiFi classification by pilot sequences |
US10038518B1 (en) | 2015-06-11 | 2018-07-31 | Marvell International Ltd. | Signaling phy preamble formats |
US10148412B1 (en) | 2015-06-25 | 2018-12-04 | Marvell International Ltd. | Methods and apparatus for clock drift mitigation |
KR102515968B1 (en) * | 2015-07-09 | 2023-03-31 | 한국전자통신연구원 | Method and apparatus for close proximity communications |
US9942060B2 (en) * | 2015-08-01 | 2018-04-10 | Intel IP Corporation | Techniques for performing multiple-input and multiple-output training using a beam refinement packet |
US10079709B2 (en) | 2015-08-14 | 2018-09-18 | Marvell World Trade Ltd. | Physical layer data unit format for a wireless communication network |
WO2017069924A1 (en) * | 2015-10-19 | 2017-04-27 | Thomson Licensing | Method and apparatus for providing time synchronization in a digital television system |
CN106406131B (en) * | 2015-12-04 | 2018-08-21 | 苏州新亚科技有限公司 | A kind of communication means of heat pump intelligence control system |
US10333669B2 (en) * | 2016-03-02 | 2019-06-25 | Qualcomm Incorporated | Apparatus and method for transmitting single channel, bonded channel, and MIMO OFDM frames with fields to facilitate AGC, timing, and channel estimation |
WO2017151932A1 (en) | 2016-03-02 | 2017-09-08 | Marvell Semiconductor, Inc. | Multiple traffic class data aggregation in a wireless local area network |
CN107889273B (en) | 2016-09-30 | 2023-12-29 | 北京三星通信技术研究有限公司 | Random access method and corresponding equipment |
US10728853B2 (en) | 2016-10-06 | 2020-07-28 | Huawei Technologies Co., Ltd. | Wake up radio frame with spectrum spreading based single carrier |
CN111226466B (en) | 2017-05-26 | 2023-05-05 | 马维尔亚洲私人有限公司 | Wake-up radio (WUR) preamble design |
US10856222B2 (en) * | 2017-09-11 | 2020-12-01 | Qualcomm Incorporated | Preambles for wake-up receivers |
WO2019079069A1 (en) | 2017-10-19 | 2019-04-25 | Marvell World Trade Ltd. | Wakeup radio (wur) packet multi-format design |
WO2019194855A1 (en) | 2018-04-03 | 2019-10-10 | Marvell World Trade Ltd. | Wakeup radio (wur) packet preamble design |
FR3086828A1 (en) * | 2018-10-01 | 2020-04-03 | Institut National Des Sciences Appliquees De Rennes | WIRELESS TRANSMISSION METHOD AND ASSOCIATED DEVICE |
FR3135371A1 (en) * | 2022-05-04 | 2023-11-10 | Uwinloc | METHOD FOR ENCODING AND DECODING A UWB MESSAGE USING MODULATION GENERATING A TIME SHIFT OF THE DATA BITS |
Citations (21)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6441810B1 (en) * | 1995-10-31 | 2002-08-27 | Lsi Logic Corporation | Telemetry encoding technique for smart stylus |
US20030099223A1 (en) * | 2001-11-28 | 2003-05-29 | Chang Li Fung | Acquisition matched filter for W-CDMA systems providing frequency offset robustness |
US20030156574A1 (en) * | 2000-05-23 | 2003-08-21 | Bernhard Raaf | Method for synchronizing a receiver with a transmitter |
US20030231607A1 (en) * | 2002-05-30 | 2003-12-18 | Scanlon Williamgiles | Wireless network medium access control protocol |
US20050013391A1 (en) * | 2003-07-17 | 2005-01-20 | Jan Boer | Signal quality estimation in a wireless communication system |
US20050059420A1 (en) * | 2003-09-16 | 2005-03-17 | Juha Salokannel | Method and system for power-based control of an ad hoc wireless communications network |
US20050066121A1 (en) * | 2003-09-24 | 2005-03-24 | Keeler Stanton M. | Multi-level caching in data storage devices |
US20050068934A1 (en) * | 2003-02-03 | 2005-03-31 | Kazuyuki Sakoda | Radio communication system, radio communication device, radio communication method, and computer program |
US20050088998A1 (en) * | 2003-09-30 | 2005-04-28 | Douglas Bretton L. | Method and apparatus for cell identification in wireless data networks |
US20050099939A1 (en) * | 2003-08-14 | 2005-05-12 | Samsung Electronics Co., Ltd. | Apparatus and method for transmitting/receiving pilot signals in an OFDM communication system |
US6922406B2 (en) * | 2000-10-03 | 2005-07-26 | Mitsubishi Denki Kabushiki Kaisha | Method of synchronizing base stations |
US20050163236A1 (en) * | 2004-01-27 | 2005-07-28 | Hammerschmidt Joachim S. | Transmission method and apparatus in a multiple antenna communication system |
US20050169292A1 (en) * | 2004-02-03 | 2005-08-04 | Sharp Laboratories Of America, Inc. | Method for beacon rebroadcast in centrally controlled wireless systems |
US20050169233A1 (en) * | 2004-06-30 | 2005-08-04 | Sharp Laboratories Of America, Inc. | System clock synchronization in an ad hoc and infrastructure wireless networks |
US20050182975A1 (en) * | 2004-01-20 | 2005-08-18 | Microsoft Corporation | Power management for a network |
WO2006051456A1 (en) * | 2004-11-09 | 2006-05-18 | Koninklijke Philips Electronics N.V. | Protecting a dsp algorithm |
US20070248072A1 (en) * | 2006-04-21 | 2007-10-25 | Samsung Electronics Co., Ltd. | Wireless network system and method of transmitting/receiving data in wireless network |
US20080049851A1 (en) * | 2006-08-22 | 2008-02-28 | Motorola, Inc. | Resource allocation including a dc sub-carrier in a wireless communication system |
US20090109945A1 (en) * | 2007-10-31 | 2009-04-30 | Qualcomm Incorporated | Method and apparatus for improved data demodulation in a wireless communication network |
US7706376B2 (en) * | 2005-12-30 | 2010-04-27 | Intel Corporation | System and method for communicating with mobile stations over an extended range in a wireless local area network |
US20100157907A1 (en) * | 2007-10-31 | 2010-06-24 | Qualcomm Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4847869A (en) * | 1987-12-04 | 1989-07-11 | Motorla, Inc. | Rapid reference acquisition and phase error compensation for radio transmission of data |
US6038549A (en) | 1997-12-22 | 2000-03-14 | Motorola Inc | Portable 1-way wireless financial messaging unit |
JP2000261462A (en) | 1999-03-11 | 2000-09-22 | Seiko Epson Corp | Radio packet communication system |
JP2002164944A (en) | 2000-11-27 | 2002-06-07 | Oki Electric Ind Co Ltd | Digital demodulator |
JP2004343509A (en) | 2003-05-16 | 2004-12-02 | Sony Corp | System, apparatus, and method for radio communication, and computer program |
WO2005112354A1 (en) | 2004-05-13 | 2005-11-24 | Koninklijke Philips Electronics N.V. | Superframe protocol packet data unit format having multirate packet aggregation for wireless systems |
US20060067280A1 (en) * | 2004-09-29 | 2006-03-30 | Howard John S | Wireless medium access control protocol with micro-scheduling |
CN100566216C (en) | 2004-10-18 | 2009-12-02 | 索尼株式会社 | Wireless communication system and radio communication device |
JP4735145B2 (en) | 2004-10-18 | 2011-07-27 | ソニー株式会社 | Wireless communication system, wireless communication device, and computer program |
CN1674483A (en) | 2005-04-01 | 2005-09-28 | 东南大学 | Iterative detecting method for space hour block code block transmission |
JP4779560B2 (en) | 2005-10-12 | 2011-09-28 | ソニー株式会社 | Wireless communication system, wireless communication apparatus, wireless communication method, and computer program |
US8418040B2 (en) | 2005-11-16 | 2013-04-09 | Qualcomm Incorporated | Method and apparatus for single carrier and OFDM sub-block transmission |
US8429502B2 (en) * | 2005-11-16 | 2013-04-23 | Qualcomm Incorporated | Frame format for millimeter-wave systems |
US7801107B2 (en) | 2006-05-25 | 2010-09-21 | Mitsubishi Electric Research Laboratories, Inc. | Method for transmitting a communications packet in a wireless communications network |
EP2263407B1 (en) | 2008-03-04 | 2016-05-11 | Koninklijke Philips N.V. | Signaling of transmission settings in multi-user systems |
CN103812816B (en) | 2008-05-15 | 2017-04-26 | 马维尔国际贸易有限公司 | Efficient physical layer preamble format |
-
2008
- 2008-10-30 US US12/262,153 patent/US8576821B2/en active Active
- 2008-10-30 US US12/262,159 patent/US20090109955A1/en not_active Abandoned
- 2008-10-30 US US12/262,155 patent/US9001815B2/en not_active Expired - Fee Related
- 2008-10-31 KR KR1020107012023A patent/KR101125349B1/en active IP Right Grant
- 2008-10-31 KR KR1020107012026A patent/KR101161077B1/en active IP Right Grant
- 2008-10-31 TW TW097142247A patent/TW200926696A/en unknown
- 2008-10-31 CN CN200880114343A patent/CN101842997A/en active Pending
- 2008-10-31 JP JP2010532303A patent/JP5290309B2/en not_active Expired - Fee Related
- 2008-10-31 TW TW097142248A patent/TW200929961A/en unknown
- 2008-10-31 JP JP2010532302A patent/JP5180314B2/en not_active Expired - Fee Related
- 2008-10-31 WO PCT/US2008/082123 patent/WO2009059232A1/en active Application Filing
- 2008-10-31 KR KR1020127008176A patent/KR20120043143A/en not_active Application Discontinuation
- 2008-10-31 EP EP08843942.7A patent/EP2223435B1/en not_active Not-in-force
- 2008-10-31 JP JP2010532300A patent/JP5280456B2/en not_active Expired - Fee Related
- 2008-10-31 WO PCT/US2008/082117 patent/WO2009059226A2/en active Application Filing
- 2008-10-31 CN CN200880114341.4A patent/CN101843164B/en active Active
- 2008-10-31 KR KR1020107012020A patent/KR101358900B1/en not_active IP Right Cessation
- 2008-10-31 TW TW097142224A patent/TW200929929A/en unknown
- 2008-10-31 EP EP08844870A patent/EP2220908A1/en not_active Withdrawn
- 2008-10-31 EP EP08844708.1A patent/EP2220907B1/en not_active Not-in-force
- 2008-10-31 WO PCT/US2008/082120 patent/WO2009059229A1/en active Application Filing
Patent Citations (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6441810B1 (en) * | 1995-10-31 | 2002-08-27 | Lsi Logic Corporation | Telemetry encoding technique for smart stylus |
US20030156574A1 (en) * | 2000-05-23 | 2003-08-21 | Bernhard Raaf | Method for synchronizing a receiver with a transmitter |
US6922406B2 (en) * | 2000-10-03 | 2005-07-26 | Mitsubishi Denki Kabushiki Kaisha | Method of synchronizing base stations |
US20030099223A1 (en) * | 2001-11-28 | 2003-05-29 | Chang Li Fung | Acquisition matched filter for W-CDMA systems providing frequency offset robustness |
US20030231607A1 (en) * | 2002-05-30 | 2003-12-18 | Scanlon Williamgiles | Wireless network medium access control protocol |
US20050068934A1 (en) * | 2003-02-03 | 2005-03-31 | Kazuyuki Sakoda | Radio communication system, radio communication device, radio communication method, and computer program |
US20050013391A1 (en) * | 2003-07-17 | 2005-01-20 | Jan Boer | Signal quality estimation in a wireless communication system |
US20050099939A1 (en) * | 2003-08-14 | 2005-05-12 | Samsung Electronics Co., Ltd. | Apparatus and method for transmitting/receiving pilot signals in an OFDM communication system |
US20050059420A1 (en) * | 2003-09-16 | 2005-03-17 | Juha Salokannel | Method and system for power-based control of an ad hoc wireless communications network |
US20050066121A1 (en) * | 2003-09-24 | 2005-03-24 | Keeler Stanton M. | Multi-level caching in data storage devices |
US20050088998A1 (en) * | 2003-09-30 | 2005-04-28 | Douglas Bretton L. | Method and apparatus for cell identification in wireless data networks |
US20050182975A1 (en) * | 2004-01-20 | 2005-08-18 | Microsoft Corporation | Power management for a network |
US20050163236A1 (en) * | 2004-01-27 | 2005-07-28 | Hammerschmidt Joachim S. | Transmission method and apparatus in a multiple antenna communication system |
US20050169292A1 (en) * | 2004-02-03 | 2005-08-04 | Sharp Laboratories Of America, Inc. | Method for beacon rebroadcast in centrally controlled wireless systems |
US20050169233A1 (en) * | 2004-06-30 | 2005-08-04 | Sharp Laboratories Of America, Inc. | System clock synchronization in an ad hoc and infrastructure wireless networks |
WO2006051456A1 (en) * | 2004-11-09 | 2006-05-18 | Koninklijke Philips Electronics N.V. | Protecting a dsp algorithm |
US7706376B2 (en) * | 2005-12-30 | 2010-04-27 | Intel Corporation | System and method for communicating with mobile stations over an extended range in a wireless local area network |
US20070248072A1 (en) * | 2006-04-21 | 2007-10-25 | Samsung Electronics Co., Ltd. | Wireless network system and method of transmitting/receiving data in wireless network |
US20080049851A1 (en) * | 2006-08-22 | 2008-02-28 | Motorola, Inc. | Resource allocation including a dc sub-carrier in a wireless communication system |
US20090109945A1 (en) * | 2007-10-31 | 2009-04-30 | Qualcomm Incorporated | Method and apparatus for improved data demodulation in a wireless communication network |
US20090109952A1 (en) * | 2007-10-31 | 2009-04-30 | Qualcomm Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
US20100157907A1 (en) * | 2007-10-31 | 2010-06-24 | Qualcomm Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
Non-Patent Citations (2)
Title |
---|
Harada et al., "CoMPA PHY proposal", IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs), IEEE 802.15-07-0693-03-003c, 7 May 2007 * |
IEEE Std 802.15.3-2003, "IEEE Standard for Information technology-Telecommunications and information exchange between systems-Local and metropolitan area networks-Specific requirements Part 15.3: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for High Rate Wireless Personal Area Networks (WPANs)", 29 September 2003 * |
Cited By (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100290451A1 (en) * | 2003-10-24 | 2010-11-18 | Broadcom Corporation | Synchronized UWB piconets for SOP (Simultaneously Operating Piconet) performance |
US8170484B2 (en) * | 2003-10-24 | 2012-05-01 | Broadcom Corporation | Synchronized UWB piconets for SOP (simultaneously operating piconet) performance |
US9001815B2 (en) | 2007-10-31 | 2015-04-07 | Qualcomm, Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
US20090109952A1 (en) * | 2007-10-31 | 2009-04-30 | Qualcomm Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
US8576821B2 (en) | 2007-10-31 | 2013-11-05 | Qualcomm Incorporated | Method and apparatus for improved data demodulation in a wireless communication network |
US9008066B2 (en) | 2007-10-31 | 2015-04-14 | Qualcomm, Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
US20090109945A1 (en) * | 2007-10-31 | 2009-04-30 | Qualcomm Incorporated | Method and apparatus for improved data demodulation in a wireless communication network |
US20100157907A1 (en) * | 2007-10-31 | 2010-06-24 | Qualcomm Incorporated | Method and apparatus for signaling transmission characteristics in a wireless communication network |
US20100226344A1 (en) * | 2008-03-12 | 2010-09-09 | Saishankar Nandagopalan | Method and System for Scheduling Multiple Concurrent Transmissions During a Contention Access Period in a Wireless Communications Network |
US9930686B2 (en) | 2008-03-12 | 2018-03-27 | Avago Technologies General Ip (Singapore) Pte. Ltd. | Method and system for scheduling multiple concurrent transmissions during a contention access period in a wireless communications network |
US9019985B2 (en) * | 2008-03-12 | 2015-04-28 | Broadcom Corporation | Method and system for scheduling multiple concurrent transmissions during a contention access period in a wireless communications network |
US8885669B2 (en) * | 2008-05-15 | 2014-11-11 | Marvell World Trade Ltd. | Method and apparatus for processing a preamble of a packet |
US8989287B2 (en) | 2008-05-15 | 2015-03-24 | Marvell World Trade Ltd. | Apparatus for generating spreading sequences and determining correlation |
US20120207181A1 (en) * | 2008-05-15 | 2012-08-16 | Hongyuan Zhang | Efficient physical layer preamble format |
US8929397B2 (en) | 2008-05-15 | 2015-01-06 | Marvell World Trade Ltd. | Efficient physical layer preamble format |
US20100111229A1 (en) * | 2008-08-08 | 2010-05-06 | Assaf Kasher | Method and apparatus of generating packet preamble |
US20100309832A1 (en) * | 2009-06-03 | 2010-12-09 | Kennan Laudel | Partial dmm reception to reduce standby power |
US8743762B2 (en) * | 2009-06-03 | 2014-06-03 | Intel Corporation | Partial DMM reception to reduce standby power |
US20100322321A1 (en) * | 2009-06-23 | 2010-12-23 | Assaf Kasher | Apparatus and methods using an efficient golay correlator running at 1.5 the sampling rate in wireless communication systems |
US8908792B2 (en) * | 2009-06-23 | 2014-12-09 | Intel Corporation | Apparatus and methods using an efficient Golay correlator running at 1.5 the sampling rate in wireless communication systems |
US20210037491A1 (en) * | 2009-08-31 | 2021-02-04 | Texas Instruments Incorporated | Short and long training fields |
US11706725B2 (en) * | 2009-08-31 | 2023-07-18 | Texas Instruments Incorporated | Short and long training fields |
US20110188445A1 (en) * | 2010-01-29 | 2011-08-04 | Elster Solutions, Llc | Clearing redundant data in wireless mesh network |
US20110188444A1 (en) * | 2010-01-29 | 2011-08-04 | Elster Solutions, Llc | High priority data reads for acquisition of real-time data in wireless mesh network |
US20110188452A1 (en) * | 2010-01-29 | 2011-08-04 | Elster Solutions, Llc | Mesh infrastructure utilizing alternative communication paths |
US20110188516A1 (en) * | 2010-01-29 | 2011-08-04 | Elster Solutions, Llc | Wireless communications providing interoperability between devices capable of communicating at different data rates |
US8855102B2 (en) * | 2010-01-29 | 2014-10-07 | Elster Solutions, Llc | Wireless communications providing interoperability between devices capable of communicating at different data rates |
US8792409B2 (en) | 2010-01-29 | 2014-07-29 | Elster Solutions, Llc | Clearing redundant data in wireless mesh network |
US8488503B2 (en) * | 2010-03-31 | 2013-07-16 | Korea Electronics Technology Institute | Magnetic field communication method for managing node with low power consumption |
US20110243267A1 (en) * | 2010-03-31 | 2011-10-06 | Korea Electronics Technology Institute | Magnetic field communication method for managing node with low power consumption |
US9961653B2 (en) | 2011-08-19 | 2018-05-01 | Qualcomm Incorporated | Beacons for wireless communication |
US11057252B2 (en) * | 2016-08-10 | 2021-07-06 | Huawei Technologies Co., Ltd. | Common synchronization signal for sliced OFDM transmission |
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