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Publication numberCN1281001 C
Publication typeGrant
Application numberCN 02801557
PCT numberPCT/IB2002/001534
Publication date18 Oct 2006
Filing date2 May 2002
Priority date10 May 2001
Also published asCN1462515A, EP1393465A1, US6978151, US20020168993, WO2002091623A1
Publication number02801557.6, CN 02801557, CN 1281001 C, CN 1281001C, CN-C-1281001, CN02801557, CN02801557.6, CN1281001 C, CN1281001C, PCT/2002/1534, PCT/IB/2/001534, PCT/IB/2/01534, PCT/IB/2002/001534, PCT/IB/2002/01534, PCT/IB2/001534, PCT/IB2/01534, PCT/IB2001534, PCT/IB2002/001534, PCT/IB2002/01534, PCT/IB2002001534, PCT/IB200201534, PCT/IB201534
InventorsS蔡, A索姆罗
Applicant皇家菲利浦电子有限公司
Export CitationBiBTeX, EndNote, RefMan
External Links: SIPO, Espacenet
Updating path loss estimation for power control and link adaption in IEEE 802. 11hwlan
CN 1281001 C
Abstract  translated from Chinese
一种用于确定位于无线局域网(WLAN)的基本服务设备(BSS)的覆盖范围以内的多个基站之间的发送功率等级的方法和设备。 A method for determining a plurality of base stations in a wireless local area network (WLAN) Basic Service Equipment (BSS) within the coverage of the method and apparatus between the transmission power level. 接收基站测量接收到的来自发送基站的信号功率,然后根据接收到的信号功率与从输入信号中提取的发送功率等级之间的差额计算路径损耗估算值。 Receiving base station measures the received signal power from the transmission base station, then the loss estimate value based on the difference between the received signal power extracted from the input signal power level between the transmission route is calculated. 按照预定的标准更新经过计算的路径损耗。 After updating the calculated path loss in accordance with predetermined criteria. 根据经过更新的路径损耗信息,调节接收基站的发送功率等级和/或发送速率。 After the path loss based on the updated information, the base station adjusting the transmit power level of the received and / or transmission rate.
Claims(7)  translated from Chinese
1.一种用于确定位于无线局域网内的基本服务设备的覆盖范围以内的多个站之间的发送功率等级的方法,其中,每个站具有发送帧的装置和接收帧的装置,该方法包括如下步骤:从发送站向接收站发送第一帧;在所述接收站测量所述接收到的第一帧的接收功率级;在所述接收站从所述接收到的第一帧中提取发送功率级;根据所述测量的接收信号功率和从所述第一帧中提取的发送功率级之间的差计算路径损耗信息;将所述计算的路径损耗信息与先前存储的计算的路径损耗信息之间的差与一个阈值相比较;根据所述计算的路径损耗信息的差是否超过所述阈值,有区别地更新路径损耗信息;在存储器介质中将所述计算的路径损耗信息存储预定的时间周期;以及根据所述计算的路径损耗信息的差,在所述接收站调节从所述接收站发送的未来帧的发送功率级和/或发送速率。 1. A method for determining transmission power level of the method is located in a plurality of stations the coverage of basic services devices within a wireless LAN between, wherein each station apparatus and the reception apparatus having a transmission frame of a frame, the method comprising the steps of: transmitting a first frame from a transmitting station to a receiving station; measuring at said receiving station receives the received power level of the first frame; extracting at said receiving station receives from the first frame to the transmission power level; difference calculating path loss information according to the measured received signal power extracted from the first frame between the transmission power level; the calculated path loss information and previously stored path loss calculation the difference is compared with a threshold value between the information; based on the path loss information of the calculated difference exceeds the threshold value, a difference update path loss information; memory medium in the path loss information calculated in the predetermined stored time period; and a path loss difference based on the calculated information, in adjusting the transmit power level of the receiving station and / or transmission rate of the next frame transmitted from the receiving station.
2.如权利要求1所述的方法,还包括以下步骤,由所述接收站响应在其中接收到的所述计算的路径损耗信息,计算新的发送功率级和/或发送速率,其中所述调节步骤是根据所述计算的新的发送功率级和/或发送速率进行的。 2. The method of 1, wherein the preceding claims, further comprising the steps of, by the receiving station in response to the path in which the calculation of the loss of the received information to calculate the new transmit power level and / or transmission rate, adjustment step is based on the new transmission power level and / or transmission rate of the calculation carried out.
3.如权利要求1所述的方法,其中,如果所述计算的路径损耗信息的差不超过所述阈值,则根据所述计算的路径损耗信息和先前计算的路径损耗信息的比例权数,更新所述路径损耗信息。 3. The method of claim 1, wherein, if the difference between the calculated path loss information does not exceed the threshold value, then the previously calculated path loss information and the loss ratio of the number of right information according to the calculated route, updating the path loss information.
4.如权利要求1所述的方法,其中,所述调节发送功率级和/或发送速率的步骤是根据所述计算的路径损耗信息的差是否超过所述阈值进行的。 4. The method of claim 1, wherein the step of adjusting the transmit power level and / or transmission rate is the difference between the loss of information exceeds the threshold value based on the calculated route.
5.一种具有功率测量电路的设备,用于确定位于无线局域网内的基本服务设备的覆盖范围以内的多个站之间的发送功率级,该设备包括:用于接收输入信号的装置;用于对所述输入信号进行解调的装置;用于测量其中接收到的所述输入信号的接收信号功率的装置;用于存储计算的路径损耗信息用于随后检索的装置;用于根据所述测量的接收信号功率与从输入信号中提取的发送功率级之间的差,计算所述路径损耗信息的装置;用于将所述计算的路径损耗信息与先前存储的计算的路径损耗信息之间的差与一个阈值相比较的装置;用于根据所述计算的路径损耗信息的差是否超过所述阈值,有区别地更新路径损耗信息的装置;以及用于根据所述计算的路径损耗信息的差,调节所述设备的发送功率级和/或发送速率的装置。 5. An apparatus having a power measurement circuit for determining a plurality of stations at a transmission power level the coverage of basic service equipment within a wireless LAN between, the apparatus comprising: means for receiving an input signal; with in demodulating the input signal; means for measuring the received signal power apparatus wherein said received input signal; calculated path loss information for storing for subsequent retrieval means; for according to the the measured difference between the received signal power extracted from the input signal between the transmission power level, the computing device path loss information; between the calculated path loss information and previously stored path loss information is used to calculate The difference comparing with a threshold value; means for loss difference information exceeds the threshold value, differentiated pathloss updating means based on the path information in the calculation; and based on the path loss information for the calculation of the difference, adjusting the transmission power level of the device and / or transmission rate means.
6.如权利要求5所述的设备,还包括用于对表示所述存储的路径损耗信息的信号进行调制的装置。 6. The apparatus according to claim 5, further comprising means for indicating said stored path loss signal information modulates the apparatus.
7.如权利要求5所述的设备,还包括用于根据所述计算的路径损耗信息确定新的发送功率级和/或发送速率的装置。 7. The apparatus of claim 5, further comprising means for calculating the path loss information according to the determination of the new transmission power level and / or transmission rate of the apparatus.
Description  translated from Chinese
用于IEEE802.11h WLAN中的功率控制和链接匹配的更新路径损耗估算 For updating the path IEEE802.11h WLAN power control and link matching loss estimate

本申请要求2001年5月10日提交的,序列号为60/290141的美国临时申请的优先权,在这里将其教导引用为参考。 This application claims the May 10, 2001 submission, the serial number for the priority of US provisional application 60/290141, where the teachings incorporated by reference.

技术领域 FIELD

本发明涉及通信系统。 The present invention relates to a communication system. 更具体讲,本发明涉及用于对在IEEE802.11无线局域网(WLAN)中的无线基站之间的路径损耗进行估算并且用这个值更准确地调节每个基站的发送功率等级和/或发送速率的系统和方法。 More particularly, the present invention relates to a radio base station for pathloss IEEE802.11 wireless local area network (WLAN) in between the estimate and adjusting the transmit power level for each base station and / or transmission rate value more accurately with this The system and method.

背景技术 BACKGROUND

一般来说,有两种不同的无线局域网络(WLAN):基于基础设施的和特定类型的。 In general, there are two different wireless local area network (WLAN): based on a particular type of infrastructure and of. 在前一种网络中,通信典型地只发生在称为基站(STAi)的无线节点与接入点(point,AP)之间,而在后一种网络中,通信发生在无线节点之间。 In the former network, communication typically occurs only between the known base station (STAi) wireless node and an access point (point, AP), and in the latter network, communication occurs between wireless nodes. AP包括基站的功能,因此也是一种STA。 The AP includes a base station function, and therefore is also a STA. 在相同的无线电覆盖范围当中的基站和AP称为基本服务设备(BSS)。 In which the same radio coverage of the base station and the AP is called the Basic Service Set (BSS).

IEEE 802.11标准对无线局域网(WLAN)规定了介质访问控制(MAC)层和物理(PHY)层特性。 IEEE 802.11 standard for wireless local area network (WLAN) provides a MAC (MAC) and physical layer (PHY) layer characteristics. 在1999年版,International StandardISO/IEC 8802-11,“信息技术——电信和系统之间的信息交换”,PartII中确定了IEEE 802.11标准,这里将其全文引用为参考。 In the 1999 edition, International StandardISO / IEC 8802-11, "Information technology - Telecommunications and information exchange between systems", PartII identified the IEEE 802.11 standard, reference herein in its entirety by reference.

目前,IEEE 802.11不提供用于给在BSS当中的无线基站之间提供动态发送功率控制(TCP)的任何机制。 Currently, IEEE 802.11 to provide any mechanism for the dynamic transmission power control (TCP) between the radio base station BSS which does not provide. 典型地,每个802.11 STA在其整个寿命中,对所有的帧发送使用一个固定的功率发送等级。 Typically, each 802.11 STA throughout its lifetime, for all the frames transmitted using a fixed transmission power level. 但是,新标准802.11h力图实现动态发送功率控制(TPC)。 However, the new standard 802.11h trying to achieve dynamic transmit power control (TPC). 因此,本发明提供一种改进的TPC机制,该机制可以不太复杂地在建议的802.11h MAC实现固件中实现。 Accordingly, the present invention provides an improved TPC mechanism that can be in a less complex realization of the proposed 802.11h MAC implemented in firmware.

发明内容 SUMMARY

本发明涉及利用通信接收器对路径损耗进行估算,从而在无线局域网(WLAN)中确定准确的发送功率控制(TPC)或者调节发送速率的系统和方法。 The present invention relates to a communication receiver to estimate the path loss to determine the accurate transmission power control (TPC) in a wireless local area network (WLAN) or adjusting the transmission rate of the system and method.

按照本发明的一个方面,提供了一种用于在无线局域网(WLAN)中,确定在位于基本服务设备(BSS)覆盖的区域当中的多个基站之间的发送功率等级和/或发送速率的方法。 According to one aspect of the present invention, there is provided a method for wireless local area network (WLAN), and determines the transmission power level is located substantially in the service equipment (BSS) area covered by the base station among a plurality of and / or transmission rate Methods. 该方法包括如下步骤:测量总的接收到的输入帧的信号功率;根据所测量的接收到的信号功率和从输入帧中提取的发送功率等级之间的差额,计算路径损耗并且按照所述计算的路径损耗调节接收基站的发送功率等级和/或发送速率。 The method comprising the steps of: measuring the total received signal power of the input frame; loss based on the difference between the received signal power measured and extracted from the input frame between the transmission power level is calculated in accordance with the calculated path and The path loss adjusting transmit power level of the receiving base station and / or transmission rate.

本发明的另一方面提供了一种用于在无线局域网(WLAN)中,确定位于基本服务设备(BSS)覆盖的区域中的多个基站之间的发送功率等级和/或发送速率的方法,其中每个基站具有用于发送信号的装置和用于接收信号的装置。 Another aspect the present invention provides a method for wireless local area network (WLAN), the transmission power level determination device located Basic Service (BSS) coverage area between a plurality of base stations and / or transmission rate of the method, wherein each base station has means for transmitting a signal and means for receiving signals. 该方法包括如下步骤:从发送基站向接收基站发送第一帧;由接收基站测量所述接收到的第一帧的接收功率等级;由接收基站从接收到的第一帧中提取发送功率等级;根据测量的接收到的信号功率和从第一帧中提取的发送功率等级之间的差额计算路径损耗;并且根据所计算的在其中接收到的路径损耗信息,调节由接收基站发送的未来帧的发送功率等级和/或发送速率。 The method comprises the steps of: transmitting a first frame from a transmitting station to a receiving station; by the receiving base station measures the received power level of the received first frame; extracted by the receiving base station transmit power level from the first frame received; According to the difference between the received signal power extracted from the first frame and the calculated transmit power level between the measured path loss; and based on the path loss information received in which the calculated, adjusted by the receiving base station transmits the next frame transmit power level and / or transmission rate. 根据与计算的路径损耗信息以及一个或多个以前计算的路径损耗信息成比例的权重,确定路径损耗信息。 In accordance with the calculated path loss information and one or more previously calculated path loss is proportional to the weight information, determine a path loss information.

本发明的另一方面提供一种具有功率电路的设备,用于在无线局域网(WLAN)中确定位于基本服务设备(BSS)覆盖的区域当中的多个基站之间的发送功率等级。 Another aspect the present invention provides an apparatus having a power circuit for determining a transmit power level a plurality of base stations located in the Basic Service Set (BSS) which is between the area covered in a wireless local area network (WLAN) in. 该设备包括:一个接收器电路,用于对输入信号进行解调;一个功率测量电路,用于测量在其中接收的输入信号的接收信号功率;一个处理器,与功率测量电路连接,用于根据接收的信号功率与从输入帧中提取的发送功率等级之间的差额,计算路径损耗信息;一个存储器,与处理器连接,用于将计算的路径损耗信息存储预定的时间周期,用于后续检索;以及,一个与处理器连接的发送器电路。 The apparatus comprising: a receiver circuit for demodulating an input signal; a power measurement circuit for measuring received signal power in which the received input signal; a processor, connected to the power measurement circuit, according the difference between the received signal power extracted from the input frame between the transmission power level, calculating the path loss information; a memory connected to the processor, for calculating the path loss information is stored for a predetermined time period, for subsequent retrieval ; and, a processor connected to the transmitter circuit.

根据以下对如附图所示的优选实施例的更详细描述,将会清楚本发明的前述以及其它特征和优点,在附图中,参考字符代表所有各个附图中相同的部分。 From the following more detailed description as illustrated in the accompanying drawings a preferred embodiment, will be apparent from the foregoing and other features and advantages of the present invention, in the drawings, reference characters represent all the various drawings the same parts.

附图说明 Brief Description

图1为示出了要对其应用本发明的实施例的无线通信系统结构的简化框图;图2示出了按照本发明的实施例的,在特定基本服务设备(BSS)当中的接入点和每个基站的简化框图;图3示出了包括对SERVICE域进行修改的802.11帧的格式,它可以用于在按照本发明的实施例的基站之间发送信息;图4为示出了按照本发明的实施例的,有选择地调节功率等级的操作步骤的流程图;图5为示出了按照本发明的实施例的,更新每个帧接收的路径损耗的操作步骤的流程图;以及图6为示出了按照本发明的实施例的,在帧发送之前更新路径损耗的操作步骤的流程图。 Figure 1 is a simplified block diagram illustrating the configuration of a wireless communication system to its embodiment of the present invention is applied; FIG. 2 shows an embodiment according to the present invention, in particular Basic Service (BSS) of which the access point A simplified block diagram of each base station and; Figure 3 shows a modification includes SERVICE field format of 802.11, it can be used in the transmission between the base station according to an embodiment of the present invention, an information; FIG. 4 is a diagram showing the follow embodiments of the present invention, for selectively adjusting the power level flowchart of the procedure; FIG. 5 is a flowchart illustrating an embodiment according to the present invention, each frame received update path loss procedure; and Figure 6 is a diagram showing a flowchart according to an embodiment of the present invention, prior to updating the path loss of frame transmission operation steps.

具体实施方式 DETAILED DESCRIPTION

在以下的描述中,为了透彻地理解本发明,提出了一些特定细节,如具体结构、接口和技术等等,目的在于解释,而不是限制。 In the following description, for a thorough understanding of the present invention, made a number of specific details, such as particular structures, interfaces, and techniques, etc., the purpose is to explain, rather than limiting. 但是,本领域技术人员应该明白,可以在脱离这些特定细节的其它实施例中实施本发明。 However, the skilled artisan will appreciate that the present invention may be embodied in that depart from these specific details other embodiments.

图1示出了要对其应用本发明实施例的典型网络。 Figure 1 shows a typical embodiment of the network to its application of the present invention. 如图1所示,接入点(AP)2通过无线链接与多个基站(STAi)耦合,这些基站通过多个无线信道相互通信并且与AP通信。 As shown, an access point (AP) 2 via wireless links with a plurality of base stations (STAi) coupling 1, the base stations communicate with each other through a plurality of radio channels and communicate with the AP. 本发明的关键原理是提供一种装置,由帧接收基站更新和估算发送基站与接收基站之间的路径损耗。 The key principles of the present invention is to provide an apparatus, a base station receives the path loss estimate and update the base transmission station and the receiving base station by the frame. 被更新的路径损耗用于通过以正好合适的功率等级和合适的发送速率发送帧来节省电池功率、避免对其它系统的干扰、调节无线电覆盖范围并且调节发送速率,但不限于此。 Path loss to be updated by just the right power level and transmission rate of a transmission frame appropriate to conserve battery power, to avoid interference with other systems, the radio coverage adjustment and adjusts the transmission rate, but is not limited thereto. 根据不同的调制和信道编码方案,IEEE 802.11的物理层(PHY)定义了多个发送速率,以便发送器能够在特定的时间,根据接收器和发送器本身之间的无线信道条件,选择多个速率中的一个速率。 Depending on the modulation and channel coding schemes, IEEE 802.11 physical layer (PHY) defines a plurality of transmission rates, so that the transmitter can be at a specific time, the receiver according to channel conditions between itself and the transmitter, selecting a plurality of rate in a rate. 特征为,发送速率越低,发送越可靠。 Characterized by lower transmission rate, the more reliable delivery. 应该注意,图1所示的网络很小,用于说明。 It should be noted, small network shown in Figure 1, for illustrative purposes. 实际上,大多数网络包括大量的基站。 In fact, most of the network includes a large number of base stations.

参照图2,图1的WLAN中的AP和每个STA可以包括具有如图2的框图所示结构的系统。 Referring to Figure 2, WLAN of Figure 1 and each STA in the AP may include a system block diagram of the structure shown in FIG. 2. AP以及STA可以包括接收器12、解调器14、功率测量电路16、存储器18、控制处理器20、计时器22、调制器24以及发送器26。 AP and STA may include a receiver 12, a demodulator 14, a power measurement circuit 16, a memory 18, control processor 20, timer 22, a modulator 24 and a transmitter 26. 图2的示范性系统10只用于说明。 Figure 2 is an exemplary system 10 for illustration. 虽然本说明可以引用通常在描述具体移动基站中所使用的术语,但是本说明以及概念同样应用于其它处理系统,包括与图2所示结构不一样的系统。 While the present description can be referenced in the description of the specific term is commonly used in the mobile station, but the present description and concepts equally apply to other processing systems, including the structure shown in Figure 2 is not the same system.

在运行当中,接收器12和发送器26与天线(没有示出)耦合,分别通过解调器14和调制器24将接收到的信号转换为对应的数字数据以及发送理想数据。 In operation, the receiver 12 and transmitter 26 and antenna (not shown) coupled, respectively, through the demodulator 14 and the modulator 24 converts the received signal into corresponding digital data and transmitting the desired data. 功率测量电路16在处理器20的控制下工作,通过从发送功率等级(以dBm为单位)中减去接收到的信号的强度来确定路径损耗,其中,发送功率等级是从其接收到的帧中转换过来的。 Power measurement circuit 16 under control of processor 20 to work through (in dBm) is subtracted intensity of the received signal from the transmission power level to determine the path loss, wherein the transmit power level from the received frame is conversion over. 对关于其它基站的路径损耗进行估算并且存储在与处理器20连接的存储器18中,用于后续检索。 To other stations on the path loss estimate and stored in the processor 20 connected to memory 18 for subsequent retrieval. 对关于相同的BSS中的其它基站的经过估算的路径损耗进行更新,随后用于计算发送功率等级。 About the same for other base stations in the BSS through a path loss estimate is updated, and then used to calculate the transmit power level. 计时器22用于删除过时的存储在存储器18中的路径损耗估算值。 The timer 22 is used to delete obsolete path stored in the memory 18 in the loss estimates. 在本实施例中,由于无线信道的特性随时间变化以及WLAN STA的潜在的可移动性,使路径损耗趋于改变,因此对路径损耗进行更新。 In the present embodiment, since the wireless channel characteristics change over time as well as WLAN STA potential mobility, so that the path loss tends to change, so the path loss update.

图3表示PHY协议数据单元(PPDU)帧的格式,该格式用于传送基站之间的发送功率等级信息。 Figure 3 shows the format of PHY protocol data unit (PPDU) frame, the format for transmitting power level information transfer between base stations. 如图3最下面部分所示,在802.11a/hPPDU帧的SERVICE域中发送发送功率等级(由TXPWR_LEVEL表示)。 The lowermost portion shown in FIG. 3, in the SERVICE field 802.11a / hPPDU frame transmits transmission power level (indicated by TXPWR_LEVEL). 将802.11a的SERVICE域做少许修改,使其包括四位TXPWR_LEVEL域。 The 802.11a's do a little modification SERVICE domain to include four TXPWR_LEVEL domain. 在图3的中间部分可以见到802.11a的原始SERVICE域格式。 In the middle portion of Figure 3 can be seen the original SERVICE domain 802.11a format. 将TXPWR_LEVEL域定义为1到16,其中,每个值代表一个特定的功率发送等级。 The TXPWR_LEVEL domain is defined as 1-16, where each value represents a particular transmit power levels. TXPWR_LEVEL用于通过从其中减去接收到的信号强度来确定路径损耗。 TXPWR_LEVEL for by subtracting from the received signal strength to determine the path loss. 在通过接收帧得到路径损耗之后,接收STA可以为其将来向另一个STA的发送巧妙地确定PHY速率以及发送功率。 Obtaining path loss by receiving frame after receiving STA can determine their future subtly PHY rate to another STA transmit and transmit power. 这样,直到STA做出判断,才独自确定发送功率等级和速率。 Thus, until the STA judge before alone determines the transmission power levels and rates. 应该注意:发送功率应该不超过由AP通过信标帧指定的最大发送功率;遵守802.11h的AP应该周期性地通过信标帧广播这个最大发送功率。 It should be noted: transmit power should not exceed by AP beacon frame specified by the maximum transmit power; 802.11h the AP should abide by the beacon frames periodically broadcast the maximum transmission power. 因此,可以避免接收错误的TXPWR_LEVEL,错误的TXPWR_LEVEL会引起对系统性能的反作用。 Therefore, to avoid receiving the wrong TXPWR_LEVEL, wrong TXPWR_LEVEL cause side effects on system performance. 可以用扩展的纠错码进行错误检测码操作。 Can be extended error correction code error detection code operation.

以下将说明按照本发明的更新路径损耗从而确定发送功率等级的操作步骤的原理。 Will be described below in accordance with the present invention, the update path loss to determine the transmission power level of the operation principle of the step.

参照图4,本发明的处理过程包括如下步骤:在步骤100中,基站STA 2接收帧。 Referring to Figure 4, the process of the invention comprises the following steps: In step 100, the base station STA 2 receives the frame. 在步骤110中,STA 2测量接收到的帧的功率等级。 In step 110, STA 2 measures the reception power level of the frame. 测量功率等级是已知的,可以按照不同方法进行的技术。 Measuring the power level is known, the method can be carried out according to different techniques. 在步骤120中,STA 2计算路径损耗并且更新路径损耗信息,路径损耗为发送功率等级与接收功率等级之间的差额。 In step 120, STA 2 calculated path loss and the path loss information is updated, the path loss as the difference between the transmission power level and the received power level between. 通过对新的和旧的路径损耗值给出不同的权将路径损耗PL更新,如下式:PL=a1*PL_new+a2*PL,(a1+a2=1,a1≥0,a2≥0),式中,PL_new表示根据新接收的帧估算的路径损耗。 Through the new and the old path loss values are given different weights to the path loss PL update the following equation: PL = a1 * PL_new + a2 * PL, (a1 + a2 = 1, a1≥0, a2≥0), wherein, PL_new represents the newly received frame according to the estimated path loss. 然后,被更新的路径损耗被用来确定需要的发送器功率,从而获得在BSS以内的理想的载波噪音比(carrier-to-noise ratio)。 Then, the updated path loss is used to determine the required transmitter power, so as to obtain within the BSS ideal carrier to noise ratio (carrier-to-noise ratio). 在步骤130中,STA 2根据在步骤120中确定的调节等级调节发送功率等级和/或发送速率。 In step 130, STA 2 determined in step 120 based on the levels of adjustment to adjust the transmit power levels and / or transmission rate.

虽然在图1中示出了有限数量的STA用于说明,但是应该理解,WLAN能够支持数量很大的STA之间的通信。 Although FIG. 1 shows a limited number of STA for illustration, it should be understood, WLAN can support communications between a large number of STA. 因此,在该图中的STA的数量不是对本发明的范围强加限制。 Therefore, the number of STA in the figure is not to impose a limit on the scope of the invention. 在这种情况下,每个STA始终监视着在BSS当中的其它STA之间以及与AP之间的路径损耗,然后,当每个发送基站向另一个基站或者AP发送帧时,可以使用路径损耗估算值调节发送功率等级。 In this case, each STA always monitors the path loss and the AP and between the BSS among other STA, then, when each of the transmitting base station to another base station or AP transmits a frame, the path loss can be used Estimates adjust transmit power levels. 对于非802.11e WLAN,仅当STA必须向其AP发送帧时,STA才需要始终监视与AP的路径损耗。 For non-802.11e WLAN, only when the STA can transmit frames to its AP, STA and the AP only needs to always monitor the path loss. 这里,发送基站可能要始终监视与经由挑选的数量的STA的路径损耗以便降低复杂程度。 Here, the transmission station may want to keep track of the path chosen by the loss of a number of STA in order to reduce the complexity. 此外,为了防止使用过时的和陈旧的路径损耗信息,本发明可以采用路径损耗信息寿命。 In addition, in order to prevent the use of outdated and obsolete path loss information, the present invention may be employed path loss information life. 为此,每当STA 2通过接收来自STA 1的帧来更新与STA 1的路径损耗估算值时,STA 2都会用图2的计时器22为每个被更新的路径损耗估算值设置一个计时器。 For this reason, whenever STA path 2 is updated by receiving a frame from the STA and STA 1 loss estimate, STA 2 will use the timer 22 of Figure 2 the loss estimate value set a timer for each path is updated . 这里,当STA 2要发送帧时,STA 2会将最近被更新的帧时间与当前时间进行比较。 Here, when the transmission frame to STA 2, STA 2 will recently updated frame time and the current time is compared.

图5示出了更新每个帧接收的路径损耗的原理。 Figure 5 shows a path for each frame received update loss principle. 在步骤200中,当在步骤200中接收来自另一个基站的帧时,计算新的路径损耗估算值。 In step 200, when receiving a frame from another base station in step 200, calculates a new path loss estimates. 在步骤210中,存储本次对路径损耗进行更新的时间,供以后使用。 In step 210, the storage of this path loss update time, for later use. 此后,在步骤220中,将新的路径损耗估算值与以前存储的路径损耗估算值进行比较,从而确定它们之间的差异是否小于某个路径损耗阈值。 Thereafter, in step 220, the new path loss estimates and previously stored path loss estimates are compared to determine the difference between them is smaller than a path loss threshold. 如果是,则在步骤240中,接收基站将根据特定的条件(PL=al*PL_new+a2*PL,其中a1+a2=1,a1≥0,a2≥0)计算路径损耗,并且将重新设置标志PL_var=0。 If so, then in step 240, the base station receiver according to specific conditions (PL = al * PL_new + a2 * PL, wherein a1 + a2 = 1, a1≥0, a2≥0) calculated path loss, and the reset Flag PL_var = 0. 反之,则在步骤230中,接收基站将擦除旧的路径损耗信息,存储新的信息,并且设置标志PL_var=1,该标志表示改变了路径损耗信息。 On the contrary, in step 230, the base station receives the path loss will erase the old information, storing the new information, and sets the flag PL_var = 1, the flag indicates that the changed path loss information. 此后,只要路径损耗的寿命不超过某个寿命阈值,并且仅当PL_var=0时,STA 2将使用被存储的从STA 1接收的路径损耗信息。 Thereafter, as long as the life of the path loss does not exceed a certain threshold lifetime, and only when PL_var = 0 时, STA 2 will be used to store the path loss information from STA 1 receives. 这种方法同样可以用于更新AP与STA之间的路径损耗信息。 This method can also be used to update the path loss between the AP and STA information.

图6示出了发送基站使用路径损耗信息的操作步骤。 Figure 6 shows a transmitting base station using the path loss procedure information. 为了在步骤300中向另一个基站发送帧,在步骤310中确定是否存在用于这个其它基站的路径损耗估算值。 In order to send a frame to another base station in step 300, it is determined in step 310 whether there are other base stations for the path loss estimate. 如果没有,在步骤320中,通过交换Request-to-Send(RTS)/Clear-to-Send(CTS)帧,可以进行新的路径损耗估算。 If not, in step 320, through the exchange Request-to-Send (RTS) / Clear-to-Send (CTS) frame, can be a new path loss estimates. CTS/RTS帧可以在不中断服务的情况下测量路径损耗。 CTS / RTS frame path loss can be measured without interruption of services. 发送基站可以通过向假设的接收STA发送RTS帧并且接收来自所述接收STA的对应CTS帧来测量路径损耗。 Transmitted by the base station transmits an RTS frame to be assumed from the receiving STA and the receiving STA receives a CTS frame to measure the corresponding path loss. 注意,CTS帧还应该在其SERVICE域中包括发送功率等级,以便使RTS帧的发送者能够估算路径损耗。 Note, CTS frames should also include in its transmission power level SERVICE field, so that the sender of RTS frames can be estimated path loss. 或者,在步骤320中,发送基站可以为了其帧发送而使用由在BSS当中的AP通过信标帧通告的最大功率等级。 Alternatively, in step 320, the base station may send its frame transmission order used by the AP in the BSS among advertised by a beacon frame the maximum power level. 如果在步骤310中存在用于其它基站的路径损耗估算值,则在步骤330中确定路径损耗估算值的时间与当前时间的差异是否小于寿命阈值,以及是否PL_var=0。 If there is a path for other base stations in step 310 the loss estimate, it is determined that the path loss estimates of time difference between the current time is less than the lifetime threshold value, and whether PL_var = 0 in step 330. 如果是,则发送基站使用在步骤310中找到的路径损耗估算值。 If so, the base station transmits using the path found in step 310 the loss estimate. 在步骤330中,如果该差异不小于预先设置的阈值或者PL_var=1,则在步骤340中,通过RTS/CTS进行新的路径损耗估算,或者该基站可以使用由在BSS当中的AP通过信标帧通告的最大功率等级或者使用过时的或已经改变的(如果PL_var=1)路径损耗估算值。 In step 330, if the difference is less than the threshold value set in advance or PL_var = 1, then in step 340, through the RTS / CTS new path loss estimates, or the base station may be used by the BSS in which the AP through the beacon frame advertised maximum power level or use outdated or has changed (if PL_var = 1) path loss estimate.

尽管已经示出并且描述了本发明的优选实施例,但是本领域的技术人员应该明白,在不脱离本发明的真实范围的情况下,可以对其进行各种改变和修改,并且可以用等同物对其要素进行替代。 While there have been shown and described preferred embodiments of the present invention, those skilled in the art should understand that, without departing from the true scope of the present invention the case may be various changes and modifications, and equivalents may be used be substituted for elements thereof. 此外,可以在不脱离中心范围的情况下进行许多修改,以适应特定情况以及本发明的思路。 In addition, many modifications may be without departing from the central scope, in order to adapt a particular situation and the idea of the invention. 因此,意图在于不是将本发明限制于按照预期为实现本发明的最佳方式而披露的特定实施例,而是本发明包括属于所附权利要求范围以内的所有实施例。 Accordingly, it is intended that the present invention is not limited to the specific way in accordance with the present invention is expected to be the best implementation and disclosed embodiments, but the present invention includes all embodiments falling within the scope of the appended claims.

Classifications
International ClassificationH04B7/26, H04B7/005, H04J11/00, H04L1/00, H04L12/28
Cooperative ClassificationH04B17/318, H04W52/10, H04W52/228, H04W52/367, H04W52/146, H04W52/26, H04W52/24, H04W52/50
European ClassificationH04W52/24, H04W52/10
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