WO2012149731A1 - Procédé, dispositif et système de synchronisation de symboles de liaison montante d'accès multi-utilisateur - Google Patents

Procédé, dispositif et système de synchronisation de symboles de liaison montante d'accès multi-utilisateur Download PDF

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Publication number
WO2012149731A1
WO2012149731A1 PCT/CN2011/079483 CN2011079483W WO2012149731A1 WO 2012149731 A1 WO2012149731 A1 WO 2012149731A1 CN 2011079483 W CN2011079483 W CN 2011079483W WO 2012149731 A1 WO2012149731 A1 WO 2012149731A1
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WO
WIPO (PCT)
Prior art keywords
user terminals
user
clock
head end
target
Prior art date
Application number
PCT/CN2011/079483
Other languages
English (en)
Chinese (zh)
Inventor
徐贵今
Original Assignee
华为技术有限公司
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 华为技术有限公司 filed Critical 华为技术有限公司
Priority to PCT/CN2011/079483 priority Critical patent/WO2012149731A1/fr
Priority to CN2011800018508A priority patent/CN102369708A/zh
Publication of WO2012149731A1 publication Critical patent/WO2012149731A1/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
    • H04L27/2647—Arrangements specific to the receiver only
    • H04L27/2655—Synchronisation arrangements
    • H04L27/2662—Symbol synchronisation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W56/00—Synchronisation arrangements

Definitions

  • the present invention relates to the field of communication systems, and in particular, to a synchronization method, apparatus and system for uplink symbols for multi-user access. Background technique
  • OFDMA Orthogonal Frequency Division Multiple Access
  • OFDM Orthogonal Frequency Division Multiple
  • the method of multi-user symbol synchronization is to realize the simultaneous interception of multiple users' complete symbols in the FFT window at the same time, so as to avoid interference between multiple users.
  • a time reference is first set, and then the head end measures the time difference between the arrival time of each user's uplink symbol and the time reference. Finally, when each user sends a symbol next time, the symbols are sent in advance by their respective time differences, so that the time for each user's uplink symbol to reach the head end is consistent.
  • the uplink symbol transmission is basically not at the same time, which in turn affects the effect of the entire multi-user uplink symbol synchronization.
  • Embodiments of the present invention provide a method, apparatus, and system for uplink symbols for multi-user access, which improve multi-user uplink symbol synchronization and improve the effect of the entire multi-user uplink symbol synchronization.
  • a method for synchronizing uplink symbols of multi-user access includes: Establishing a local clock on each of at least two user terminals;
  • Each of the user terminals transmits an uplink symbol of the OFDM to the target head at a predetermined time point based on the synchronized local clock.
  • a clock establishing unit configured to respectively establish a local clock in at least two user terminals
  • a clock adjusting unit configured to adjust respective local clocks of the at least two user terminals to be synchronized
  • a sending unit configured to send, by each of the user terminals, an uplink symbol of the O F DM to the target head end at a predetermined time point based on the synchronized local clock.
  • a synchronization system for uplink symbols of multi-user access includes: at least two user terminals and a target head end;
  • the at least two user terminals are configured to respectively establish a local clock in the at least two user terminals; then, adjust respective local clocks of the at least two user terminals to be synchronized; and finally each of the user terminals is based on synchronization a local clock, sending an uplink symbol of the OF DM to a target head end at respective predetermined time points;
  • the target head end is configured to establish a target clock at the target head end; and receive an uplink symbol of the OFDM DM sent by the at least two user terminals at respective predetermined time points.
  • the method, device, and system for synchronizing the uplink symbols of the multi-user access provided by the embodiment of the present invention firstly establish a local clock in each of the at least two user terminals; and then adjust the local clocks of the at least two user terminals to be synchronized; Finally, each of the user terminals transmits the uplink symbol of the OFDM to the target headend at respective predetermined time points based on the synchronized local clock.
  • the method for establishing a synchronous clock achieves the uplink symbol synchronization of the user, and the effect of the uplink synchronization of the entire multi-user is greatly improved.
  • FIG. 1 is a flow chart of a method for synchronizing uplink symbols of multi-user access according to Embodiment 1 of the present invention
  • FIG. 2 is a schematic structural diagram of a synchronization apparatus for uplink symbols of multi-user access according to Embodiment 1 of the present invention
  • FIG. 3 is a schematic diagram of a synchronization system for uplink symbols of multi-user access according to Embodiment 1 of the present invention.
  • This embodiment provides a method for synchronizing uplink symbols of a multi-user access. As shown in FIG. 1, the method includes:
  • At least two user terminals respectively establish local clocks in the at least two user terminals.
  • the target head end when the target head end sends the downlink symbol to the user terminal, the time T 1 of the current target clock is recorded; when a certain user terminal receives the downlink symbol, the current local clock is recorded.
  • the time is T2; when the user terminal sends the uplink symbol to the target head end, the time of recording the current local clock is T3, and when the target head end receives the uplink symbol, the current record is recorded.
  • the target clock is T4; the local clock is synchronized with the target clock according to the time offset of the local clock and the target clock, thereby synchronizing the respective local clocks of the at least two user terminals.
  • 0ffset [(T3+T2)-(T4+Tl)]/2, where Off set represents the time offset between the local clock and the target clock.
  • Each of the user terminals sends the uplink symbol of the OFDM to a target head end at a predetermined time point based on the synchronized local clock.
  • the predetermined time point of each user terminal may be a time point of advancing a respective line delay time with respect to a same time point, wherein the respective line delay time is that the corresponding user terminal reaches the target The line delay time at the head end.
  • each of the user terminals is based on the synchronized local clock, and the specific method for calculating the line delay time is when the target head end sends the downlink symbol to the user terminal, and the current target clock is recorded.
  • Time T1 when a user terminal receives the downlink symbol, the time of recording the current local clock is T2; when the certain user terminal sends the uplink symbol to the target head end, the current local clock is recorded. The time is T3.
  • the line delay time of user 1 is Delayl
  • the line delay time of user 2 is Delay2
  • the line delay time of user 3 is Delay3.
  • the three user terminals send symbols to the target head end
  • the user 1 sends a symbol in advance according to the relatively same time point
  • the user 2 sends a symbol in advance to the opposite time point
  • the user 3 is relatively the same as the above.
  • Delay3 sends the symbol in advance, so that the symbols sent by the three users can reach the target head end accurately.
  • each of the user terminals reaches the line delay time of the target head end Line delay time, because the target head end can receive the uplink symbols sent by each user terminal at the same time, so that the target head end can simultaneously intercept the complete symbols sent by each user terminal to perform FFT and other demodulation parts.
  • the respective predetermined time points of each user terminal are the same time point, that is, each of the user terminals sends an uplink symbol to the target head end at the same time point based on the synchronized local clock.
  • the embodiment provides a synchronization device for uplink symbols of multi-user access.
  • the device includes: a clock establishing unit 21, a clock adjusting unit 22, a sending unit 23, and a synchronizing unit 24.
  • the clock establishing unit 21 is configured to separately establish a local clock in the at least two user terminals.
  • the clock adjustment unit 22 is configured to adjust respective local clocks of the at least two user terminals to be synchronized.
  • the sending unit 23 is configured to send, by each of the user terminals, the uplink symbol of the OFDM to the target head end at a predetermined time point based on the synchronized local clock.
  • the predetermined time point of each user terminal may be a time point of advancing a respective line delay time with respect to a same time point, wherein the respective line delay time is that the corresponding user terminal reaches the target The line delay time at the head end.
  • each of the user terminals is based on the synchronized local clock, and the specific method for calculating the line delay time is when the target head end sends the downlink symbol to the user terminal, and the current target clock is recorded.
  • Time T1 when a user terminal receives the downlink symbol, the time of recording the current local clock is T2; when the certain user terminal sends the uplink symbol to the target head end, the current local clock is recorded.
  • the time is T3.
  • the line delay time of user 1 is Delayl
  • the line delay time of user 2 is Delay2
  • the line delay time of user 3 is Delay3.
  • the three user terminals send symbols to the target head end
  • the user 1 sends a symbol in advance according to the relatively same time point
  • the user 2 sends a symbol in advance to the opposite time point
  • the user 3 is relatively the same as the above.
  • Delay3 sends the symbol in advance, so that the symbols sent by the three users can reach the target head end accurately.
  • the target head end can receive the uplink symbols sent by the respective user terminals at the same time, thereby ensuring the target.
  • the head end can simultaneously intercept the complete symbols sent by each user terminal to perform FFT and other demodulation parts.
  • the respective predetermined time points of each user terminal are the same time point, that is, each of the user terminals sends an uplink symbol to the target head end at the same time point based on the synchronized local clock.
  • the synchronization unit 24 is configured to synchronize the local clocks of the at least two user terminals with the target clock.
  • the target head end sends the downlink symbol to the user terminal
  • the time T1 of the current target clock is recorded; when a certain user terminal receives the downlink symbol, the current local clock is recorded.
  • the time is T2; when the user terminal sends the uplink symbol to the target head end, the time of recording the current local clock is T3, and when the target head end receives the uplink symbol, the current record is recorded.
  • the first embodiment provides a synchronization system for uplink symbols of multiple users. As shown in FIG. 3, the method includes: at least two user terminals 31 and a target head end 32.
  • At least two user terminals 31, configured to respectively establish local clocks in the at least two user terminals; and then adjust respective local clocks of the at least two user terminals to be synchronized; and finally each of the user terminals is based on synchronization
  • the local clock transmits an uplink symbol to the target head end at respective predetermined time points.
  • a target head end 32 configured to establish a target at the target head end; receiving an uplink symbol of the OFDM sent by the at least two user terminals at respective predetermined time points.
  • the at least two user terminals 31 are further configured to synchronize the local clocks of the at least two user terminals with a target clock.
  • the method, device, and system for synchronizing the uplink symbols of the multi-user access provided by the embodiment of the present invention firstly establish a local clock in each of the at least two user terminals; and then adjust the local clocks of the at least two user terminals to be synchronized; Finally, each of the user terminals transmits the uplink symbol of the OFDM to the target head end at respective predetermined time points based on the synchronized local clock.
  • the method for establishing a synchronous clock achieves the uplink symbol synchronization of the user, and the effect of the uplink synchronization of the entire multi-user is greatly improved.
  • the device for synchronizing the uplink symbols of the multi-user access may implement the foregoing method embodiment.
  • Method and device for synchronizing uplink symbols of multi-user access provided by embodiments of the present invention
  • the system can be applied to the field of communication systems, but is not limited to this.
  • the storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

Abstract

L'invention porte sur un procédé, un dispositif et un système de synchronisation de symboles de liaison montante d'accès multi-utilisateur, concernant le domaine des systèmes de communication, et réalisant la synchronisation des symboles de liaison montante multi-utilisateur tout en améliorant l'effet de la synchronisation de symboles de liaison montante multi-utilisateur entière. Le procédé consiste à : en premier lieu, établir séparément des horloges locales pour au moins deux terminaux utilisateurs ; et synchroniser ensuite les horloges locales respectives des au moins deux terminaux utilisateurs ; enfin, envoyer par chacun des terminaux utilisateurs, à une tête de réseau cible, un symbole de liaison montante OFDM à des instants respectivement désignés sur la base des horloges locales synchronisées. La présente invention est applicable au domaine des systèmes de communication.
PCT/CN2011/079483 2011-09-08 2011-09-08 Procédé, dispositif et système de synchronisation de symboles de liaison montante d'accès multi-utilisateur WO2012149731A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/CN2011/079483 WO2012149731A1 (fr) 2011-09-08 2011-09-08 Procédé, dispositif et système de synchronisation de symboles de liaison montante d'accès multi-utilisateur
CN2011800018508A CN102369708A (zh) 2011-09-08 2011-09-08 多用户接入的上行符号的同步方法、装置及系统

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2011/079483 WO2012149731A1 (fr) 2011-09-08 2011-09-08 Procédé, dispositif et système de synchronisation de symboles de liaison montante d'accès multi-utilisateur

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WO2012149731A1 true WO2012149731A1 (fr) 2012-11-08

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WO (1) WO2012149731A1 (fr)

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CN111459009B (zh) * 2020-04-21 2021-08-17 哈尔滨工业大学 一种多数字电子设备同步的随机误差估计系统及其估计方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1287426A (zh) * 1999-06-26 2001-03-14 阿尔卡塔尔公司 产生用于上行信道的时钟信号的方法
CN1656713A (zh) * 2002-05-29 2005-08-17 汤姆森特许公司 卫星通信系统中使能无线返回信道信号传输的方法和装置
CN1868172A (zh) * 2004-06-08 2006-11-22 三菱电机株式会社 基站间时刻同步方法、主定时装置以及基站

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1287426A (zh) * 1999-06-26 2001-03-14 阿尔卡塔尔公司 产生用于上行信道的时钟信号的方法
CN1656713A (zh) * 2002-05-29 2005-08-17 汤姆森特许公司 卫星通信系统中使能无线返回信道信号传输的方法和装置
CN1868172A (zh) * 2004-06-08 2006-11-22 三菱电机株式会社 基站间时刻同步方法、主定时装置以及基站

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