CN1997237B - Mobile communication terminal and mobile communication base station apparatus supporting switching - Google Patents
Mobile communication terminal and mobile communication base station apparatus supporting switching Download PDFInfo
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- CN1997237B CN1997237B CN200710007939.0A CN200710007939A CN1997237B CN 1997237 B CN1997237 B CN 1997237B CN 200710007939 A CN200710007939 A CN 200710007939A CN 1997237 B CN1997237 B CN 1997237B
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- 238000010295 mobile communication Methods 0.000 title claims description 13
- 238000000034 method Methods 0.000 claims abstract description 45
- 230000005540 biological transmission Effects 0.000 claims abstract description 35
- 230000001413 cellular effect Effects 0.000 description 5
- 238000004891 communication Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/08—Reselecting an access point
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
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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
- H04W52/04—TPC
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- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
A hand-over method in an orthogonal frequency division multiple access system and an apparatus therefor are provided. Before a call channel is transmited to a new target cell, a user equipment transmits a preamble having preliminarily set symbol intervals and a power increase and decrease level to a target cell. The target cells decide an up-link transmission timing control value and a transmission power control value according to the received preamble. The target cell transmits a result to the user equipment. The user equipment transmits a call channel adjusted according to the transmission timing control value and the transmission power control value to the target cell. Thereby the subcarrier allocating to users can be received in protecting intervals during handoff.
Description
The application is to be the divisional application of the application for a patent for invention that December 26, application number in 2003 are 200310124731.9, denomination of invention is " changing method of cellular ofdma system and equipment " applying date.
Technical field
The present invention relates to a kind of changing method and equipment in OFDMA (OFDM, orthogonal frequency divisionmultiple access) system.More particularly, the present invention relates in a kind of OFDMA system for obtaining equipment and the method from orthogonality between the subcarrier frequency of mobile terminal arrival community between transfer period.
Background technology
OFDM (OFDM, orthogonal frequency division multiplexing) is a kind of multi-carrier modulation method having outstanding performance aspect multipath and mobile reception environment.
OFDM modulator approach is carried out serial parallel conversion to data flow, is loading parallel data, and send them with preset frequency on spaced multiple subcarriers.Therefore,, because transmitted signal is divided into multiple channels, it is longer than the code-element period of the single carrier method of equivalent data rates that code-element period becomes, and therefore has good multipath characteristics.In addition, because subcarrier has orthogonality, can prevent that each subcarrier from quoting the channel frequency except the frequency of this subcarrier, therefore, subcarrier likely superposes in frequency spectrum.
But in multi-path environment, the transmission of code element can be delayed, therefore can be by next symbol interference.In order to prevent inter symbol interference, the symbol interval being sent out comprises the guard interval (guard interval) before effective symbol interval (valid symbolinterval) and effective code element interval.Therefore,, in the time that the delay of code element transmission is shorter than the delay of guard interval, there will not be inter symbol interference, and guaranteed the orthogonality between subcarrier.
Due to this advantage, OFDM modulation technique except broadcast technology also for mobile communication.OFDMA system based on OFDM is a kind of multiple-user access method, and wherein adjacent community is used identical frequency band, and subcarrier is assigned to each user.In order to keep communication quality and to guarantee mobility, OFDMA system is supported selective call handoff functionality (intercall handover function).
Fig. 1 is illustrated in the handoff procedure in mobile communication system.
Switching is the process that changes community and call path, to keep call path in the time that the current original position community 20 belonging to of terminal 10 moves to adjacent Target cell 30 at mobile terminal 10.
In cdma system, traditional changing method adopts make-before-break (make-before-break) method, for after setting up the calling channel of Yu Xin community, interrupts the calling channel with original position community.In Wireless LAN system, traditional changing method also adopts break-before-make (break-before-make) method, for after being switched to Xin community, sets up new calling channel.
But, when carry out switching according to the handoff procedure that is applied to traditional C DMA system in OFDMA cellular system time, in the up link from mobile terminal to community, guarantee that the orthogonality between user but becomes problem.As mentioned above, will in guard interval, receive subcarrier, to guarantee to receive in OFDMA system the orthogonality of subcarrier, wherein guard interval represents that predetermined time postpones.Therefore, need to control the transmit timing from terminal to community.
But, in the prior art, mobile terminal in switching state by controlling transmit timing by choosing at random the control channel applying in original position community, but, Target cell after handoff procedure but lacks the information about mobile terminal, therefore, can produce in the early stage suitable transmit timing control and initial power and arrange the difficulty of aspect.
Therefore, the changing method that the changing method of traditional cdma cellular formula system is applied to OFDMA cellular system can not ensure intercarrier orthogonality, and can consume the too much hand-off process time.
Summary of the invention
Advantage of the present invention is to provide a kind of for controlling switching device and the method for timing, while switching, can guarantee the up link orthogonality between user, and set up suitable initial transmission power in the cellular system with box lunch application OFDMA.
In one aspect of the invention, in a kind of mobile communication system, comprise for the method that user terminal is switched to Target cell from original position community: switch controller command execution is switched; User terminal sends to be had predetermined symbol interval and increased power/falls low-level preamble (preamble) to Target cell; Target cell determines that according to the preamble receiving up link sends timing controlled value and transmission power control value; Target cell sends and comprises the radio link control command that sends timing controlled value and transmission power control value to user terminal; And user terminal sends calling channel to Target cell, calling channel is controlled by sending timing controlled value and transmission power control value.
The predetermined symbol interval of preamble and increased power/reduction level are shared by user terminal and Target cell.
Determine and send timing controlled value and transmission power control value, make Target cell can within predetermined time, receive the calling channel of user terminal and another user's calling channel.
In another aspect of the present invention, a kind ofly support the mobile communication terminal switching to comprise: preamble generator, for generation of thering is the low-level preamble of predetermined symbol interval and increased power/fall; Transmitter, for before being established to the calling channel of Target cell, sends preamble to Target cell; Receiver, for according to preamble reception result, receives radio link control command from Target cell; And terminal control unit, for control transmission timing and the transmitted power of calling channel according to the radio link control command receiving.
In another aspect of the present invention, a kind of mobile communication base station equipment of supporting switching comprises: receiver, for after command execution is switched, before setting up channel call, receives preamble from user terminal; Base station controller, sends timing controlled value and power control value for the up link of determining user terminal according to the measurement result of preamble; And transmitter, for sending the radio link control command that comprises up link transmission timing controlled value and power control value to user terminal.
Brief description of the drawings
Accompanying drawing is included in and forms a part for specification, for embodiments of the invention are described, and is used for explaining principle of the present invention together with specification:
Fig. 1 is illustrated in the handoff procedure in mobile communication system;
Fig. 2 illustrates according to the flow chart of the changing method of the preferred embodiments of the present invention;
Fig. 3 illustrates for according to the transmitted signal of the changing method of the preferred embodiments of the present invention;
Fig. 4 illustrates according to the flow chart of signal stream between the terminal of the preferred embodiments of the present invention, Target cell, original position community and switch controller; With
Fig. 5 A and 5B illustrate for according to the block diagram of the terminal of the changing method of the preferred embodiments of the present invention and base station.
Embodiment
In the following detailed description, realize best mode of the present invention by explanation by the inventor is desired simply, only illustrate and described the preferred embodiments of the present invention.As by what realize, can, completely without departing from the invention, carry out various apparent amendments to the present invention.Therefore, it is illustrative that in fact drawing and description are considered to, instead of restrictive.
Describe according to the switching device of the preferred embodiments of the present invention and method referring now to accompanying drawing.
Fig. 2 illustrates for according to the outline flowchart of the changing method of the preferred embodiment of the present invention.
In the time that mobile terminal moves to Target cell from original position community, in step S10, in the time meeting switching condition, MSC (mobile switching centre, mobile switching center) or MTSO (MTSO, mobile telephone switching office) in the switch controller command execution that provides switch.
In the time that switch controller sends switching command to mobile terminal via Target cell, in step S20, mobile terminal, according to predetermined symbol interval and increased power/reduction level, sends preamble by the public time slot of uplink data frames.
Switching preamble based on from receiving in the mobile terminal of switching state, in step S30, Target cell is identified for the transmission timing controlled value of mobile terminal and suitable initial transmission power value, and use downlink channel to send control command, to the transmission timing of mobile terminal and the radio link of initial transmission power are set.
Receiving when switching the radio link control command of preamble, in step S40, mobile terminal extracts timing controlled value and power control value within radio link control command, and controls and send timing and transmitted power.
After step S40 finishes, in step S50, mobile terminal sends and has switched report to switch controller via Target cell.
When the transmission timing in up link with initial power is controlled to and when finishing switching, in step S60, mobile terminal is via Target cell and new calling channel executive communication.
According to the method described above, before finishing switching, mobile terminal uses preamble to be provided for determining the transmission timing of up link and the information of initial power to base station.
Fig. 3 illustrates for according to the preamble of the changing method of the preferred embodiments of the present invention.
In the time receiving switching command, mobile terminal 100, before sending call information, uses public time slot 300 to send and has the preamble 310 of predetermined power level to the base station 200 of Target cell.Because timing information and the power level information of preamble are shared by base station 200 and mobile terminal 100, the timing information of the preamble of base station 200 actual receptions and power level information and predetermined timing information and power level information, to produce timing controlled value and power control value.Determine timing controlled value and power control value according to the pre-stored value of the look-up table corresponding to preamble information, or utilize by the value of actual reception and the value of storage and predetermined equation calculates.Can utilize by more preset preamble information and the actual value receiving and determine that any method of timing controlled value and power control value obtains these values.
In the time that timing controlled value and power control value are determined, radio link information 400 is sent to mobile terminal 100 via downlink control channel.
Fig. 4 illustrates according to the flow chart of signal stream between the terminal of the preferred embodiments of the present invention, Target cell, original position community and switch controller.
Comprise user terminal, original position community, Target cell and switch controller for the mobile communication system of carrying out switching.
In the time that user terminal is positioned at original position community, in step S100, the calling channel that is set to original position community is called out, and in step S110, the switching threshold information via broadcast channel from switch controller reception of neighboring cell.
In step S120, based on the information relevant to switching receiving via broadcast channel, the downlink channel quality of each user terminal report neighbor cell and original position community is to original position community, and original position community sends downlink channel quality to switch controller.
In step S130, switch controller is used the downlink channel quality information of the original position community of being reported by user terminal and neighbor cell to carry out to switch and is arranged, and is the best community of user terminal selecting.
In step S131, switch controller is to selecting the Target cell request as best community to be used for the radio resources allocation of switching, and in step S132, in the time completing radio resources allocation, Target cell reports that user terminal in switching state is to switch controller.
In the time receiving radio resources allocation for switching from Target cell and complete response, in step S140, switch controller order original position community, Target cell and user terminal are carried out and are switched.In step S150, user terminal receives switching command, and in up link, send and switch preamble, and in step S160, Target cell receives and switches preamble from the user terminal in switching state, send the control information for setting up radio link, such as transmission timing and the initial transmission power of user terminal.
In step S170, when receive via downlink channel for the radio link of setting up control information time, user terminal has switched to switch controller via Target cell report, and in step S181, switch controller is cancelled to the original position community request radio resource of caller party terminal.In step S182, the radio resource of the user terminal in switching state is interrupted in original position community according to switch controller, and report interrupt status is to switch controller.In step S190, user terminal is called out Target cell, stops the calling to original position community, and call targets community.
Fig. 5 A and 5B illustrate for according to the block diagram of the terminal of the changing method of the preferred embodiments of the present invention and base station.
Now the changing method based on above-mentioned is described to the operation of terminal 100 and base station 200.
In the time that the terminal of Fig. 5 A receives switching command from switching device, switching preamble generator 122 in digital signal transmitter 121 is according to predetermined symbol interval and increased power/reduction level, by using digital signal transmitter and receiver 120 and analog signal transmitter and receiver 130 to send preamble to base station.
Preamble is sent to base station controller 210 via the analog signal transmitter of base station and receiver 230 and digital signal transmitter and receiver 220.In the time that base station controller 210 receives and analyzes preamble, send timing controller 211 and power controller 212 and determine transmission timing controlled value and the initial power control value of up link, by using digital signal transmitter and receiver 220 and analog signal transmitter and receiver 230, the value that sends radio link control command form via control channel is to user terminal.
By control figure signal transmitter 121, send timing value and initial gain value and controlled, user terminal is formed into the uplink channel of base station.
Therefore, after switching while being established to the initial call path of Target cell, owing to considering that the current environment of user terminal controls up link and send regularly and transmitted power, can in guard interval, receive subcarrier, and guarantee intercarrier orthogonality.
As mentioned above, Target cell obtains user terminal information in the time that ofdma communication system switches, and guarantees the orthogonality between the user in Target cell.
Although the most practical described the present invention with preferred embodiment in conjunction with thinking at present, should understand, the present invention is not limited to the disclosed embodiments, but on the contrary, expection covers various amendments and the equivalents within essence and the scope that is included in appended claim.
Claims (11)
1. a method of switching in the travelling carriage of mobile communication system, described method comprises:
Receive the switching command message from source base station;
Send for determining that up link sends the preamble of timing controlled value and up link initial transmission power controlling value to target BS;
Receive from the up link of target BS and send timing controlled value;
Receive the up link initial transmission power controlling value from target BS;
By using this up link to send timing controlled value, up link transmission timing is set; And
By using this up link initial transmission power controlling value that up link initial transmission power level is set.
2. according to the process of claim 1 wherein, it is definite by using this preamble at target BS place that described up link sends timing controlled value.
3. according to the process of claim 1 wherein, up link transmission timing is set and is undertaken by up link transmission timing being set by described up link transmission timing controlled value.
4. according to the process of claim 1 wherein, described up link initial transmission power controlling value is definite by using this preamble at target BS.
5. according to the method for any one in claim 1 to 4, also comprise:
Send handoff completion message to target BS; And
Start to communicate by letter with target BS.
6. according to the method for any one in claim 1 to 4, wherein, described preamble is that the public time slot of distributing to uplink data frames by use sends.
7. according to the method for any one in claim 1 to 4, wherein, described preamble has predetermined symbol interval.
8. a method of switching in the target BS of mobile communication system, described method comprises:
Receive the predetermined preamble signal from travelling carriage;
Determine that by using this preamble up link sends timing controlled value;
Determine up link initial transmission power controlling value by using this preamble;
Send this up link to travelling carriage and send timing controlled value; And
Send this up link initial transmission power controlling value to travelling carriage.
9. method according to Claim 8, also comprises:
Receive the handoff completion message from travelling carriage; And
Start to communicate by letter with target BS.
10. according to Claim 8 or 9 method, wherein, described preamble is that the public time slot of distributing to uplink data frames by use sends.
11. according to Claim 8 or 9 method, wherein, described preamble has predetermined symbol interval.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR1020030036255A KR100541876B1 (en) | 2003-06-05 | 2003-06-05 | A method for hand over in OFDMA cellular system and an apparatus used therin |
| KR0036255/03 | 2003-06-05 |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2003101247319A Division CN1575016A (en) | 2003-06-05 | 2003-12-26 | Switching method and apparatus for cellular ofdma system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1997237A CN1997237A (en) | 2007-07-11 |
| CN1997237B true CN1997237B (en) | 2014-11-05 |
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ID=34510784
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2003101247319A Pending CN1575016A (en) | 2003-06-05 | 2003-12-26 | Switching method and apparatus for cellular ofdma system |
| CN200710007939.0A Expired - Lifetime CN1997237B (en) | 2003-06-05 | 2003-12-26 | Mobile communication terminal and mobile communication base station apparatus supporting switching |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2003101247319A Pending CN1575016A (en) | 2003-06-05 | 2003-12-26 | Switching method and apparatus for cellular ofdma system |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR100541876B1 (en) |
| CN (2) | CN1575016A (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100810333B1 (en) * | 2004-06-15 | 2008-03-04 | 삼성전자주식회사 | Apparatus and method for supporting soft handover in a broadband wireless access communication system |
| KR100790133B1 (en) * | 2005-07-08 | 2008-01-02 | 삼성전자주식회사 | System and method for a handover between frequency assignment in a communication system |
| JP4202355B2 (en) * | 2005-08-23 | 2008-12-24 | 株式会社エヌ・ティ・ティ・ドコモ | Base station and communication system |
| US7894332B2 (en) * | 2007-06-27 | 2011-02-22 | Motorola Mobility, Inc. | Power profile reshaping in orthogonal frequency division multiple access symbols |
| CN101365222B (en) * | 2007-08-10 | 2011-05-04 | 上海华为技术有限公司 | Reverse sharing signaling channel access method, mobile station and base station |
| US8676208B2 (en) | 2008-06-11 | 2014-03-18 | Mediatek Inc. | Scanning and handover operation in multi-carrier wireless communications systems |
| CN103874144A (en) * | 2009-04-24 | 2014-06-18 | 联发科技股份有限公司 | Handover method of multi-carrier wireless OFDM system |
| WO2013035941A1 (en) * | 2011-09-05 | 2013-03-14 | 엘지에릭슨 주식회사 | Method for determining a pdsch start symbol of an ec between heterogeneous networks, and mobile communication system therefor |
| CN103139886B (en) * | 2011-12-05 | 2018-06-08 | 中兴通讯股份有限公司 | A kind of method and base station controller for controlling transmission power |
| CN105025540A (en) * | 2014-04-30 | 2015-11-04 | 中兴通讯股份有限公司 | Method and device for GSM (Global System for Mobile Communication) soft hand-off |
| CN105578520B (en) * | 2014-10-08 | 2019-04-26 | 展讯通信（上海）有限公司 | A kind of cell switching processing system and method and mobile terminal |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5940743A (en) * | 1997-06-05 | 1999-08-17 | Nokia Mobile Phones Limited | Power control of mobile station transmissions during handoff in a cellular system |
| CN1352828A (en) * | 1999-05-27 | 2002-06-05 | 高通股份有限公司 | Forward link transmission power control during soft handoff |
| US6487191B1 (en) * | 1997-11-17 | 2002-11-26 | Electronics And Telecommunications Research Institute | Power control apparatus and method with interference reduction during soft handoff in CDMA cellular communication systems |
-
2003
- 2003-06-05 KR KR1020030036255A patent/KR100541876B1/en active IP Right Grant
- 2003-12-26 CN CNA2003101247319A patent/CN1575016A/en active Pending
- 2003-12-26 CN CN200710007939.0A patent/CN1997237B/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5940743A (en) * | 1997-06-05 | 1999-08-17 | Nokia Mobile Phones Limited | Power control of mobile station transmissions during handoff in a cellular system |
| US6487191B1 (en) * | 1997-11-17 | 2002-11-26 | Electronics And Telecommunications Research Institute | Power control apparatus and method with interference reduction during soft handoff in CDMA cellular communication systems |
| CN1352828A (en) * | 1999-05-27 | 2002-06-05 | 高通股份有限公司 | Forward link transmission power control during soft handoff |
Non-Patent Citations (1)
| Title |
|---|
| JP特开2000-224636A 2000.08.11 * |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20040106942A (en) | 2004-12-20 |
| CN1997237A (en) | 2007-07-11 |
| KR100541876B1 (en) | 2006-01-10 |
| CN1575016A (en) | 2005-02-02 |
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Granted publication date: 20141105 |