WO2008052406A1 - Procédé d'envoi de sch dans un système tdd - Google Patents

Procédé d'envoi de sch dans un système tdd Download PDF

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Publication number
WO2008052406A1
WO2008052406A1 PCT/CN2007/001613 CN2007001613W WO2008052406A1 WO 2008052406 A1 WO2008052406 A1 WO 2008052406A1 CN 2007001613 W CN2007001613 W CN 2007001613W WO 2008052406 A1 WO2008052406 A1 WO 2008052406A1
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WO
WIPO (PCT)
Prior art keywords
sch
symbol
time
slot
cyclic suffix
Prior art date
Application number
PCT/CN2007/001613
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English (en)
Chinese (zh)
Inventor
Shuqiang Xia
Chunli Liang
Original Assignee
Zte Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zte Corporation filed Critical Zte Corporation
Publication of WO2008052406A1 publication Critical patent/WO2008052406A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/26035—Maintenance of orthogonality, e.g. for signals exchanged between cells or users, or by using covering codes or sequences

Definitions

  • the present invention relates to the field of digital communications, and in particular to a cell search technique for a time division duplex system based on OFDM (Orthogonal Frequency Division Multiplexing) technology, and more particularly to a synchronization channel in an orthogonal frequency division multiplexing time division duplex system. (Synchronization Channel, SCH) is sent.
  • OFDM Orthogonal Frequency Division Multiplexing
  • SCH Synchronization Channel
  • the capture process is also known as the cell search process.
  • the cell search mainly obtains the time and frequency synchronization with the target cell, and also obtains the target cell identification number and some other basic information.
  • the cell search process is mainly based on a Synchronization Channel (SCH), that is, the time synchronization with the target cell, the cell identification number or the cell identification group number information, etc. are obtained according to the synchronization channel.
  • SCH Synchronization Channel
  • BCH broadcast channel
  • pilot a pilot
  • the cell search process is a hierarchical process, so the corresponding synchronization channel (SCH) is divided into a primary synchronization channel (Primary SCH, P-SCH) and a secondary synchronization channel (Secondary SCH, S-SCH).
  • Primary SCH Primary synchronization channel
  • S-SCH secondary synchronization channel
  • the P-SCH is used to implement slot timing and frequency calibration.
  • the S-SCH is mainly used to implement frame timing and cell identification number or cell identification group number and some cell/system related information detection.
  • FIG. 1 is a schematic diagram of a frame structure of a time division duplex system based on orthogonal frequency division multiplexing (OFDM) technology.
  • a 10 ms radio frame includes two equal length subframes, each of which has a length of 5 ms.
  • Each subframe further includes 7 general time slots and 3 special time slots.
  • the seven general time slots are TS0 ⁇ TS6, and the length of each general time slot is 0.675ms.
  • the three special time slots are: DwPTS time slot, GP time slot and UpPTS time slot, where DwPTS time slot
  • the downlink synchronization signal is fixedly transmitted in the time slot, and the time length is 75 s
  • the GP time slot is the uplink and downlink protection time slot of the TDD (Time Division Duplex) system, and the time length is also 75 s
  • the UpPTS time slot is the uplink.
  • TI time slot interval
  • each OFDM symbol is a long cyclic prefix (CP), wherein the long cyclic prefix length is 16.67 s, and the data portion length is 66.67 ⁇ ⁇ , and the corresponding slot interval length is 8.33 s;
  • CP long cyclic prefix
  • the data portion length is 66.67 ⁇ ⁇
  • the corresponding slot interval length is 8.33 s;
  • TS0 contains 9 OFDM symbols
  • each OFDM symbol is a short cyclic prefix, wherein the short cyclic prefix length is 7.29 ⁇ ⁇ , and the data portion length is also 66.67 s, and the corresponding slot interval length is 9.38 ⁇ ⁇ .
  • the data portion length of each OFDM symbol is 66.67 ⁇ , so the slot interval length of TSO is mainly determined according to the cyclic prefix length of each OFDM symbol. Usually, no data is sent in the slot interval.
  • the upward arrow in Fig. 1 indicates that the time slot is an uplink time slot
  • the downward arrow indicates that the time slot is a downlink time slot.
  • the time slot TS0 is fixed as a downlink time slot
  • the time slot TS1 is fixed as an uplink time slot
  • other time slots can be flexibly allocated as uplink or downlink time slots according to service requirements.
  • the downlink primary synchronization signal P-SCH is fixedly transmitted in the DwPTS slot, and the secondary synchronization signal S-SCH is transmitted on the last OFDM symbol of TS0. Therefore, there is a slot interval between the time slot DwPTS and the last OFDM symbol of TS0. Since TS0 can adopt a long cyclic prefix structure or a short cyclic prefix structure, the time between P-SCH and S-SCH The gap interval is an amount that varies with the length of the cyclic prefix used by TS0.
  • the technical problem to be solved by the present invention is to provide a method for transmitting a synchronization channel in a time division duplex system based on orthogonal frequency division multiplexing technology, so as to improve the performance of cell search and reduce the complexity of device implementation.
  • the present invention is applicable to a time division duplex system in which a primary synchronization channel P-SCH is fixedly transmitted on a DwPTS time slot.
  • the invention provides a method for transmitting a synchronization channel of a time division duplex system. Based on the orthogonal frequency division multiplexing technology, the primary synchronization channel P-SCH is transmitted on the downlink time slot DwPTS, and the secondary synchronization channel S-SCH is at the end of the TS0 time slot.
  • An Orthogonal Frequency Division Multiplexing (OFDM) OFDM symbol transmission characterized in that: a cyclic suffix of an S-SCH symbol is transmitted on a slot interval between an S-SCH and a P-SCH, and a time length of the cyclic suffix is used according to the OFDM symbol.
  • the cyclic prefix length is determined so that the constant C is different at each cycle.
  • the slot interval between the S-SCH and the P-SCH is ⁇ CP, and the slot interval may not transmit a cyclic suffix of the S-SCH symbol
  • 9 OFDM symbols the slot interval between the S-SCH and the P-SCH is ⁇ ⁇ , and the L SCP - L LCF portion of the slot interval may be used to transmit a cyclic suffix of the S-SCH symbol.
  • the slot interval between the S-SCH and the P-SCH may all be used to send a cyclic suffix of the S-SCH symbol.
  • ⁇ ⁇ indicates that the TS0 contains 8 OFDM symbols, the S-SCH and the slot interval between said P-SCH; the ⁇ represents the time TS0 contains nine OFDM symbols, the slot spacing between the S-SCH and the P-SCH; T represents the said S - The length of time in the data portion of the SCH signal.
  • the data content of the cyclic suffix may be the same as the data content of the beginning portion of the S-SCH symbol. Moreover, the cyclic suffix may be placed at the end of the S-SCH symbol and connected to the S-SCH symbol.
  • the mobile station can directly extract the S-SCH signal after completing the slot timing synchronization by using the P-SCH, omitting the step of detecting the cyclic prefix length, reducing the processing delay and reducing the implementation complexity. 2. According to the method proposed by the present invention, when the S-SCH timing lags, the data transmitted in the last symbol of TS0 can still maintain orthogonality, effectively avoiding inter-carrier interference.
  • FIG. 1 is a schematic diagram of an embodiment of a time slot structure in a TDD system
  • FIG. 2 is a schematic diagram of an embodiment of a method for transmitting a synchronization channel in the prior art
  • FIG. 3 is a schematic diagram of transmission of a synchronization channel according to an embodiment of the present invention.
  • FIG. 4 is a schematic diagram of transmission of a synchronization channel according to Embodiment 2 of the present invention.
  • FIG. 5 is a schematic diagram of transmission of a third synchronization channel according to an embodiment of the present invention. - a preferred embodiment of the invention
  • the main feature of the present invention is: transmitting a cyclic suffix of the S-SCH symbol at part or all of the time slot interval between the S-SCH and the P-SCH, and requiring that the time slot not used as the cyclic suffix is a time A constant that does not depend on the OFDM symbol cyclic prefix length variation.
  • the length of the cyclic suffix portion in the slot interval is also determined according to the length of time of the OFDM symbol cyclic prefix.
  • the time that is not used as the cyclic suffix in the slot interval is a constant that does not depend on the cyclic prefix length variation of the OFDM symbol, the mobile station can directly extract the S-SCH signal after completing the slot timing synchronization using the P-SCH.
  • the data of the S-SCH symbol is: s ( 0 ) , s ( 1 ) ....s ( N-1 ), and a piece of data is appended to the symbol, and the content and the beginning part of the data of the S-SCH symbol.
  • the content is the same, and the new data is composed of: s ( 0 ) , s ( 1 ) ....s ( N-1 ) , s ( 0 ) , s ( 1 ) , s ( 2 ) (where N is S-SCH The number of data in the symbol); that is, the data of the beginning portion of the S-SCH symbol is placed as a cyclic suffix at the end of the S-SCH symbol, and is connected to the S-SCH symbol.
  • the s (0), s ( 1 ), and s (2) at the end of the data are the cyclic suffixes of the symbol.
  • the length of the cyclic suffix can be long or short. If 10 data can be placed in the slot interval, the cyclic suffix can be: s (0), s (1), s (2), ... s (9).
  • the time that is not used as the cyclic suffix in the slot interval is a constant that does not depend on the cyclic prefix length change. If C is set, the following method can be used to insert the cyclic suffix:
  • the length of the inserted cyclic suffix is ⁇ - C; where c ranges from: o ⁇ c ⁇ z iCP .
  • FIG. 3 is a schematic diagram of transmission of a synchronization channel according to an embodiment of the present invention.
  • the time that is not used as the transmission cyclic suffix in the slot interval corresponding to the TS0 slot under the two cyclic prefix structures is a constant that does not depend on the cyclic prefix length variation of the OFDM symbol, and is equal to ⁇ > (:.
  • the method for transmitting the channel the mobile station can directly extract the S-SCH signal after completing the slot timing synchronization by using the P-SCH, thereby avoiding the step of detecting the cyclic prefix length, which reduces the processing delay and reduces the implementation complexity.
  • the S-SCH signal is transmitted near the P-SCH signal (the interval between the P-SCH and the S-SCH is not more than 9.38 ⁇ ⁇ ), and the P-SCH signal has higher energy than the common pilot. And density, thus providing better channel estimation for the S-SCH, thereby ensuring better demodulation performance of the S-SCH signal.
  • FIG. 4 is a schematic diagram of transmission of a synchronization channel according to Embodiment 2 of the present invention.
  • this diagram corresponds to the case of 0 ⁇ C ⁇ Z CP .
  • TS0 ⁇ slots with short cyclic prefix interval - ⁇ cyclic suffix portion for transmitting the S-SCH signal
  • cyclic postfix with long cyclic prefix TS0 C portion of slot intervals for transmitting a signal s_ SC H .
  • the time that is not used as the transmission cyclic suffix in the slot interval corresponding to the TS0 time slot under the two cyclic prefix structures is also an independent loop.
  • the constant of the prefix length change, and both are C.
  • the interval between the P-SCH and the S-SCH is smaller, and thus the channel estimation provided by the P-SCH more realistically reflects the channel variation of the control signal.
  • the structure of two different cyclic prefix lengths adopts a cyclic suffix, and the S-SCH is more resistant to channel frequency selective fading. Therefore, the transmission method shown in FIG. 4 can provide better methods than the method shown in FIG. Performance.
  • FIG. 5 is a schematic diagram of transmission of a third synchronization channel according to an embodiment of the present invention.
  • this method increases the length used to transmit the cyclic suffix, thus making the S-SCH more effective against the frequency selective fading of the channel.
  • ⁇ denotes the duration of the S-SCH signal (excluding the cyclic prefix, the cyclic suffix part), that is, the length of time in which the data portion.
  • the timing of the P-SCH is accurate, regardless of whether the TS0 contains 8 OFDM symbols or 9 OFDM symbols, the content of the S-SCH signal received by the receiver is exactly the same as that of the transmitting end, because according to the long cyclic prefix
  • the time length ⁇ between the S-SCH signal and the P-SCH signal (as shown in Figures 3, 4 and 5), together with the information contained in the cyclic suffix, is sufficient to receive the S-SCH. The signal is complete.
  • the mobile station since the mobile station can directly extract the S-SCH signal after completing the slot timing synchronization by using the P-SCH, the step of detecting the cyclic prefix length is omitted, which not only reduces the processing delay, but also reduces the processing delay. Reduced implementation complexity.
  • the data transmitted in the last symbol of TS0 still contains the complete S-SCH data information, so the orthogonality can still be maintained to avoid the inter-carrier interference; if the method proposed by the present invention is not adopted, then When the -SCH timing lags, the data transmitted at the last symbol of TS0 is incomplete, and its orthogonality cannot be guaranteed, causing severe inter-carrier interference.
  • the S-SCH is transmitted close to the P-SCH (the maximum interval between the S-SCH and the P-SCH is 9.38 s), and the P-SCH has higher energy and density than the common pilot, so
  • the S-SCH signal provides better channel estimation, which in turn ensures better demodulation performance of the S-SCH.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un procédé d'envoi d'un canal de synchronisation (SCH) dans un système duplex à répartition dans le temps (TDD), selon un multiplexage par répartition en fréquence orthogonale (MROF). Ce procédé comporte l'envoi de SCH primaire (P-SCH) dans DwPTS, l'envoi de SCH secondaire (S-SCH) au moyen du dernier symbole MROF dans TS0, l'envoi du suffixe cyclique (CS) du symbole S-SCH dans l'intervalle de temps situé entre S-SCH et P-SCH. La durée de CS est déterminée selon la longueur du préfixe cyclique (CP) des symboles MROF, de manière que le temps dans TS0 non utilisé pour envoyer CS est invariable, lorsqu'un CP différent est utilisé.
PCT/CN2007/001613 2006-10-31 2007-05-17 Procédé d'envoi de sch dans un système tdd WO2008052406A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200610149899A CN101175058B (zh) 2006-10-31 2006-10-31 一种时分双工系统同步信道的发送方法
CN200610149899.9 2006-10-31

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CN102711261B (zh) * 2012-05-24 2014-10-15 大唐移动通信设备有限公司 一种应用于双模rru中的子帧配置方法及装置
EP3157277B1 (fr) 2014-07-23 2019-09-25 Huawei Technologies Co., Ltd. Procédé de transmission et équipement de transmission pour un réseau local sans fil
CN109565489B (zh) * 2016-08-04 2020-07-07 华为技术有限公司 用于在无线通信系统中的符号和子帧对齐发送数据的方法和发射器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1533196A (zh) * 2003-03-26 2004-09-29 华为技术有限公司 一种在时分双工系统中进行小区搜索的方法
CN1535512A (zh) * 2001-05-22 2004-10-06 在无线通信系统中同步基站的方法
CN1553586A (zh) * 2003-12-19 2004-12-08 大唐移动通信设备有限公司 Td-scdma系统中的下行同步校准方法和装置
CN1780174A (zh) * 2004-11-19 2006-05-31 凯明信息科技股份有限公司 时分双工系统中小区搜索第一和第二步骤的并行迭代方法

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3581072B2 (ja) * 2000-01-24 2004-10-27 株式会社エヌ・ティ・ティ・ドコモ チャネル構成方法及びその方法を利用する基地局
CN100414859C (zh) * 2002-06-12 2008-08-27 电子科技大学 一种ofdm通信系统的帧尾插入控制比特方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1535512A (zh) * 2001-05-22 2004-10-06 在无线通信系统中同步基站的方法
CN1533196A (zh) * 2003-03-26 2004-09-29 华为技术有限公司 一种在时分双工系统中进行小区搜索的方法
CN1553586A (zh) * 2003-12-19 2004-12-08 大唐移动通信设备有限公司 Td-scdma系统中的下行同步校准方法和装置
CN1780174A (zh) * 2004-11-19 2006-05-31 凯明信息科技股份有限公司 时分双工系统中小区搜索第一和第二步骤的并行迭代方法

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