WO2018188659A1 - 一种信号同步方法及装置 - Google Patents

一种信号同步方法及装置 Download PDF

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WO2018188659A1
WO2018188659A1 PCT/CN2018/083072 CN2018083072W WO2018188659A1 WO 2018188659 A1 WO2018188659 A1 WO 2018188659A1 CN 2018083072 W CN2018083072 W CN 2018083072W WO 2018188659 A1 WO2018188659 A1 WO 2018188659A1
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signal
received signal
received
synchronization
coarse synchronization
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French (fr)
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杨旭磊
程晨
白栎旸
刘览
孙远航
李彧
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Sanechips Technology Co Ltd
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Sanechips Technology Co Ltd
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    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/0413—MIMO systems
    • 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

Definitions

  • This document relates to the field of wireless communication technologies, and in particular, to a signal synchronization method and apparatus.
  • the performance of the synchronization technology is directly related to the performance of the entire communication system. It can be said that without accurate synchronization algorithms, reliable data transmission is impossible, and it is a prerequisite for reliable transmission of information.
  • OFDM Orthogonal Frequency Division Multiplexing
  • the system has high requirements for synchronization. Inter-channel interference (ICI) and inter-symbol interference (ISI) introduced by various synchronization errors may cause the receiver to fail to receive data correctly, and may also destroy sub-carriers in the OFDM system. Orthogonality.
  • ICI Inter-channel interference
  • ISI inter-symbol interference
  • an automatic gain control (AGC) unit (301) sends a signal received from each antenna (302) to a modem after triggering a lock reception signal.
  • AGC automatic gain control
  • the symbol synchronizer (304) first performs positioning synchronization.
  • the result of the symbol synchronizer positioning synchronization provides a reference point for the Fast Fourier Transformation (FFT) unit (305) to enable the next series of operations (e.g., demodulation).
  • FFT Fast Fourier Transformation
  • Symbol positioning synchronization is to determine the starting position of the OFDM symbol, that is, the starting position of each FFT window. As shown in Figure 2, symbol positioning synchronization may occur in four situations: 1) FFT window 1 (Window1) indicates that the timing estimation point is correct, there is no deviation, and the demodulated data should be correct; 2) FFT window 2 (Window2) indicates that the timing estimation point falls within the Cyclic Prefix (CP) of the symbol and leads the optimal timing point; 3) FFT window 3 (Window3) indicates that the timing estimation point falls on the next symbol cycle. Within the prefix, and lags behind the optimal timing point; 4) FFT window 4 (Window4) indicates that the timing estimate point falls within the data portion of the previous symbol and leads the cyclic prefix of the symbol.
  • FFT window 1 indicates that the timing estimation point is correct, there is no deviation, and the demodulated data should be correct
  • FFT window 2 indicates that the timing estimation point falls within the Cyclic Prefix (CP) of the symbol and leads the optimal timing point
  • the first one is an ideal case and does not cause symbol positioning error; if the second type is not much different from the ideal point, the introduced positioning deviation can be recovered by the equalizer, but if the difference is large, It will affect the performance of channel smoothing, thus reducing the performance of the equalizer; the third and fourth cases will introduce ISI and ICI, which will greatly reduce the performance of the system, so it is to be avoided.
  • the allowed positioning deviation is determined according to the number of points smoothed by the channel. It is assumed that the number of smoothing points selected is 11, and the phase of the continuous 11 points is guaranteed to be continuous when smoothing, that is, the maximum phase difference of all frequency points does not exceed ⁇ . Then the allowed time deviation ⁇ t is
  • the time interval between two points in the time domain is 50 ns, and ⁇ f is equal to 312.5 kHz, so ⁇ t is equal to 150 ns, and the range of the actual positioning point is 3 points ahead or behind the ideal positioning point, so that Affects smoothing performance.
  • each antenna has a fixed delay.
  • MIMO Multiple-Input Multiple-Output
  • the technical problem to be solved in this paper is to provide a signal synchronization method and device, which can ensure the positioning accuracy when the received signals are synchronized in the multi-input and multi-output system, and reduce the computational complexity.
  • the embodiment of the invention provides a signal synchronization method, including:
  • the automatic gain control AGC unit locks the received signal
  • the signal received by each receiving antenna is subjected to delay autocorrelation processing, and after receiving the first time delay, the received signal corresponding to each channel is compared with the received signal.
  • the thresholds are compared, and it is determined whether the coarse synchronization is completed according to the comparison result of each channel;
  • the local cross-correlation processing is performed on each received signal, and the results of the local cross-correlation processing are weighted and added and filtered, and the maximum value is searched from the filtered signal, and the determination is completed when the maximum value is searched. Fine synchronization.
  • An embodiment of the present invention provides a signal synchronization apparatus, including:
  • the coarse synchronization module is configured to perform delay autocorrelation processing on the signals received by the respective receiving antennas when the automatic gain control AGC unit locks the received signals, and after receiving the processed signals of the respective channels after the delay of the first time length Comparing the reference thresholds corresponding to the received signals of the road, and determining whether to complete the coarse synchronization according to the comparison result of each channel;
  • the fine synchronization module is configured to perform local cross-correlation processing on each received signal after the coarse synchronization is completed, perform weighted accumulation and filtering on the results of the local cross-correlation processing, and search for the maximum value from the filtered signal. When the maximum value is reached, it is determined that the fine synchronization is completed.
  • the embodiment of the present invention provides a signal synchronization method and device, and delays autocorrelation processing on a signal received by each receiving antenna when the automatic gain control AGC unit locks the received signal, and delays the first
  • the received signal processed by each channel is compared with the reference threshold corresponding to the received signal of the channel, and the coarse synchronization is determined according to the comparison result of each channel; after the coarse synchronization is completed, the local cross-correlation processing is performed on each received signal.
  • the results of the local cross-correlation processing are weighted and filtered, and the maximum value is searched from the filtered signal, and the fine synchronization is determined when the maximum value is searched.
  • the embodiment of the invention can ensure the positioning accuracy when the received signals are synchronized in the MIMO system and reduce the computational complexity.
  • FIG. 1 is a schematic diagram of a digital receiver receiving a signal and performing demodulation in the prior art
  • FIG. 2 is a schematic diagram of positioning points of symbol positioning synchronization in the prior art
  • FIG. 3 is a flowchart of a signal synchronization method according to Embodiment 1 of the present invention.
  • FIG. 4 is a block diagram showing a coarse synchronization process in Embodiment 1 of the present invention.
  • FIG. 5 is a timing diagram of delay-triggered coarse synchronization detection according to Embodiment 1 of the present invention.
  • FIG. 6 is a block diagram showing a fine synchronization process in Embodiment 1 of the present invention.
  • Example 7 is a schematic diagram of triggering coarse synchronization detection using AGC lock time delay in Example 1 of the present invention.
  • Example 8 is a schematic diagram of reference threshold generation and coarse synchronization detection triggering in Example 2 of the present invention.
  • FIG. 9 is a schematic diagram of a signal synchronization apparatus according to Embodiment 2 of the present invention.
  • an embodiment of the present invention provides a signal synchronization method, including:
  • Step S310 delaying autocorrelation processing is performed on the signals received by the receiving antennas when the automatic gain control AGC unit locks the received signals, and the processed signals received by the respective channels and the received signals are processed after the first time delay. Corresponding reference thresholds are compared, and it is determined whether the coarse synchronization is completed according to the comparison result of each channel;
  • Step S320 after the coarse synchronization is completed, performing local cross-correlation processing on each received signal, performing weighted accumulation and filtering on the results of the local cross-correlation processing, searching for the maximum value from the filtered signal, and searching for the maximum value.
  • the time is determined to complete the fine synchronization.
  • the delaying autocorrelation processing is performed on the signal received by any one of the receiving antennas, including:
  • the symbol autocorrelation operation of the delayed N beat can be expressed by the following formula (2-1):
  • N is the period of the Shorting Training Field (STF). If the sampling frequency is 20 MHz, then N is equal to 16; r(n) is the received signal, and r * (n) is the conjugate of the received signal. ;sign() is a symbolic function;
  • the short training sequence is used for signal detection, AGC power adjustment, coarse synchronization, etc.
  • the STF belongs to a sequence known by the transmitting side and the receiving side, and the sequence can determine what signal is received and can Subsequent fine synchronization processing provides some reference and buffering.
  • the first length of time is a length of time after a duration T1 of the short training sequence minus a maximum time T2 max of the AGC unit lock receiving signal;
  • the time t2 at which the AGC unit locks the received signal does not exceed T2 max ;
  • the reference threshold corresponding to each received signal is obtained by averaging the delayed autocorrelation results of the received signal in a short training sequence period and then multiplying by 0.5.
  • comparing the received signal received by each path with a reference threshold corresponding to the received signal, and determining whether to complete the coarse synchronization according to the comparison result of each channel including:
  • the received signal after one way reaches the reference threshold corresponding to the received signal of the way and reaches the reference threshold for a period of time, it is determined that the received signal of the way satisfies the coarse synchronization requirement
  • the coarse synchronization is determined to be completed when at least one of the received signals satisfies the coarse synchronization requirement.
  • the continuous holding time is a preset value, such as 5 sampling points
  • the performing local cross-correlation processing on any one of the received signals includes:
  • c(n) is the tap coefficient of the filter, and the tap coefficients of the filter are designed according to the value of the long training sequence;
  • r * () is the conjugate of the received signal;
  • the results of the local cross-correlation processing are weighted and filtered, including:
  • the product of the number of taps a of the filter and the sampling interval of the received signal is greater than or equal to the maximum delay between the transmitting antennas; the value of the tap coefficients corresponding to the transmitted signal of the first transmitting antenna among the a plurality of tap coefficients is greater than the other taps.
  • the value of the coefficient; any one of the transmitting antennas other than the first transmitting antenna leads the first transmitting antenna to transmit a signal.
  • the maximum value is searched from the filtered signal, and the position where the maximum value appears is the position where the LTF ends, and is also the beginning of the next symbol. Since each symbol has a guard interval in front, the position according to the end of the LTF and the guard interval are The length determines the starting position of each symbol, so it is determined that the fine synchronization is completed when the maximum value is searched.
  • the coarse synchronization process may include the following steps:
  • the first trigger signal is generated by the trigger signal generator (401);
  • the trigger signal generator (401) delays the first time threshold T1 and outputs a second trigger signal to the averaging operation unit (408), and the averaging unit extracts a delay of a certain window length.
  • the autocorrelation result is averaged to obtain a reference threshold, and the coarse synchronization detection is triggered at the same time;
  • the comparison unit (409) corresponding to each receiving antenna compares the autocorrelation result outputted by the modulo modulo unit with the reference threshold output by the averaging unit to obtain a 1-bit comparison result;
  • the 1-bit comparison result output by the comparison unit (409) corresponding to each receiving antenna is sent to the logical operation unit (410) to generate a 1-bit coarse synchronization result; for example, when the coarse synchronization result is 1, the determination is coarse. Synchronization completed;
  • the AGC lock signal is used for delay triggering, and the delay auto-correlation result of a certain window length is extracted to obtain a threshold value, and the coarse synchronization detection is triggered at the same time, and the result of the delay autocorrelation will be sequentially Compared with the threshold, when a point is lower than the threshold, the coarse synchronization will not be triggered. Only the result of the delay autocorrelation will trigger the coarse synchronization 5 times below the threshold. Since the coarse synchronization detection does not start from the AGC lock, but the reference threshold is started, which reduces the coarse synchronization detection during the period when the AGC locks to the threshold generation, which can effectively reduce the occurrence of false synchronization.
  • the purpose of the above coarse synchronization is to trigger the fine synchronization calculation and provide a suitable calculation window length for fine synchronization.
  • a long training field (LTF) is used to design a digital filter with a tap number of 64 in a period.
  • the received signal passes through the filter, which is actually a filter.
  • the tap coefficients are subjected to cross-correlation operations, and the cross-correlation operations can be expressed by the following formula (2-2):
  • N represents the length of the cross-correlation calculation, N is equal to 64; r(m) is the received signal, and c(n) is the tap coefficient of the filter;
  • the period of the long training sequence LTF is four times that of the STF, and is the same as the period of one OFDM, and can be used for fine synchronization, fine frequency offset estimation, and signal estimation.
  • the embodiment of the present invention utilizes its strong correlation characteristic to locally store a processed LTF (i.e., the tap coefficient of the filter). When the received signal is related to the local LTF (peak occurs), it is considered to be synchronized.
  • the embodiment of the present invention passes the filter with a tap number of 6 through the calculation result of the cross correlation, and then searches for the maximum value of the filter output within a certain range, that is, the final fine The result of the synchronization.
  • the third situation may occur in the synchronization position, that is, the timing estimation point falls within the cyclic prefix of the next symbol and lags behind the optimal timing point, so the positioning synchronization can be improved by the positioning offset processing.
  • Dynamic range For example, moving the sync position forward by 6 points starts to extract each OFDM symbol, and before the FFT, the value of the first six points of the symbol is moved to the last position of the symbol, which allows the positioning point to be optimally positioned. Point to swing left and right. This ensures that the positioning synchronization point can move around the optimal positioning point without introducing inter-symbol interference, which improves the dynamic range of the positioning synchronization.
  • the fine synchronization process may include the following steps:
  • the signals received by the receiving antennas are sent to the corresponding first filters (602) for filtering processing, and then sent to the corresponding modulo units (603). Mold processing
  • the tap coefficients of the filter are correspondingly processed according to the time domain signal of the long training sequence.
  • the symbols of the filter tap coefficients are determined after taking the symbols of the time domain signals of the long training sequence, and then according to the time domain signals of the long training sequence.
  • the magnitude of the amplitude, the filter coefficient is set to 0, 1, 2, because the amplitude is large, strong anti-noise ability, high confidence, so give a larger weight.
  • the tap coefficient c(n) of the filter is a complex number consisting of 0, 1, 2 (for example, 1+2i);
  • the second filter is equivalent to a sliding window summation, and one of the values is weighted, and the sliding window can reduce the influence of different delays and multipaths of the antenna, and the weighting can increase the peak intensity of the first transmitting antenna. It is advantageous to locate the peak of the first antenna and improve the accuracy of the positioning result.
  • the received signal enters the modem.
  • the coarse synchronization detection is not performed immediately, but the detection is performed after a certain time delay.
  • the time (T) of the delay is obtained by subtracting the time (701) of the AGC latest lock from the end of the short training sequence for coarse synchronization (702).
  • the threshold (704) is obtained after the delay time (T), which causes the coarse synchronization detection (705) to occur after the threshold is generated. This causes the AGC to lock (703), and the coarse synchronization detection (705) does not perform coarse synchronization detection before the trigger, which effectively reduces the occurrence of false synchronization.
  • the received signal is subjected to delay autocorrelation processing to obtain an output result (801), and the output threshold (801) is used to start the calculation of the threshold value (802) by the AGC lock delay trigger, and the threshold value is calculated from the trigger.
  • the 16 values of the output result (801) are extracted and then averaged. After the threshold value calculation is completed, the threshold value starts to take effect, the coarse synchronization detection starts, and then the output result (801) and the threshold value pass through the comparator (803).
  • the comparison result is passed through a 5-tap filter (804) having a tap coefficient of all 1, and the output data of the filter is compared with a value (805) in the register, wherein The value is set to 5, and the comparison result is equal to prove that the antenna coarse synchronization is detected; the function of the 5-tap filter (804) is that the five consecutive points reach the threshold value to be considered as a coarse synchronization trigger.
  • the coarse synchronization detection result of all antennas is processed by a logical operation or (806), that is, as long as one antenna coarse synchronization is detected, the coarse synchronization process is completed.
  • the coarse synchronization completion will trigger the fine synchronization calculation and detection.
  • the tap coefficients of the first filter (602) are designed according to the time domain values of the long training sequence, and the real and imaginary parts of the long training sequence time domain values are respectively averaged, and the average value is divided by 2 Obtain the threshold value, divide the real part and the imaginary part of the time domain value of the long training sequence by their corresponding threshold values, and then round off the calculation result (the absolute value exceeds 2) to obtain the final filter.
  • c(n) compresses the time domain signal of the original LTF, that is, the characteristic of the time domain signal of the LTF is represented by a small bit, and X(n) is an LTF time domain signal.
  • N 64 represents the period of the LTF, and round() is the rounding function;
  • c'(n) is a tap coefficient (ie, a locally stored long training sequence);
  • the second filter has a total of 6 taps, and the tap coefficients are: ⁇ 1, 1, 1, 1, 2, 1 ⁇ , and the second filter can resist multipath effects and different antennas.
  • the delay between the two uses the weight value of the peak of the first receiving antenna to locate the synchronization result on the first receiving antenna.
  • an embodiment of the present invention provides a signal synchronization apparatus, including:
  • the coarse synchronization module 901 is configured to perform delay autocorrelation processing on the signals received by the respective receiving antennas when the automatic gain control AGC unit locks the received signals, and after receiving the processed signals of the respective channels after the delay of the first time length Comparing the reference thresholds corresponding to the received signals of the road, and determining whether to complete the coarse synchronization according to the comparison result of each channel;
  • the fine synchronization module 902 is configured to perform local cross-correlation processing on each received signal after the coarse synchronization is completed, perform weighted accumulation and filtering on the results of the local cross-correlation processing, and search for the maximum value from the filtered signal. When the maximum value is found, it is determined that the fine synchronization is completed.
  • the coarse synchronization module is configured to perform delayed autocorrelation processing on signals received by any one of the receiving antennas in the following manner:
  • N is the period of the short training sequence STF
  • r(n) is the received signal
  • r * (n) is the conjugate of the received signal
  • sign() is the sign function
  • the reference threshold corresponding to each received signal is obtained by averaging the delayed autocorrelation results of the received signal during a short training sequence period and multiplying by 0.5.
  • the coarse synchronization module is configured to compare the processed received signals with the reference thresholds corresponding to the received signals in the following manner, and determine whether to complete the coarse synchronization according to the comparison result of each channel:
  • the received signal after one way reaches the reference threshold corresponding to the received signal of the way and reaches the reference threshold for a period of time, it is determined that the received signal of the way satisfies the coarse synchronization requirement
  • the coarse synchronization is determined to be completed when at least one of the received signals satisfies the coarse synchronization requirement.
  • the fine synchronization module is configured to perform local cross-correlation processing on any one of the received signals in the following manner:
  • c(n) is the tap coefficient of the filter, and the tap coefficient of the filter is designed according to the value of the long training sequence; r * () is the conjugate of the received signal.
  • the fine synchronization module is configured to perform weighted accumulation and filtering on the results of the local cross-correlation processing in the following manner:
  • the product of the number of taps a of the filter and the sampling interval of the received signal is greater than or equal to the maximum delay between the transmitting antennas; the value of the tap coefficients corresponding to the transmitted signal of the first transmitting antenna among the a plurality of tap coefficients is greater than the other taps.
  • the value of the coefficient; any one of the transmitting antennas other than the first transmitting antenna leads the first transmitting antenna to transmit a signal.
  • the automatic gain control AGC unit locks the received signal
  • the signal received by each receiving antenna is subjected to delay autocorrelation processing, and the received processing is processed after the first time delay.
  • the signal is compared with the reference threshold corresponding to the received signal of the road, and whether the coarse synchronization is completed according to the comparison result of each channel; after the coarse synchronization is completed, the local cross-correlation processing is performed on each received signal, and the result of the local cross-correlation processing of each channel is performed.
  • Weighted accumulation and filtering are performed to search for the maximum value from the filtered signal, and it is determined that the fine synchronization is completed when the maximum value is searched.
  • the embodiment of the invention can ensure the positioning accuracy when the received signals are synchronized in the MIMO system and reduce the computational complexity.

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Abstract

本文公开了一种信号同步方法和装置。所述信号同步方法包括：在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。

Description

一种信号同步方法及装置 技术领域
本文涉及无线通信技术领域，尤其涉及的是一种信号同步方法及装置。
背景技术
同步技术的性能直接关系到整个通信系统的性能。可以说没有准确的同步算法，就不可能进行可靠的数据传输，它是信息可靠传输的前提。而对于正交频分复用(Orthogonal Frequency Division Multiplexing，简称OFDM)系统来说，系统对于同步的要求很高。因为各种同步误差引入的载波间干扰(Inter Channel Interference，简称ICI)、符号间干扰(inter symbol interference，简称ISI)会使得接收机无法正确接收数据，并且还会破坏OFDM系统内各子载波的正交性。
如图1所示，一个通常的OFDM系统接收机中，自动增益控制(Automatic Gain Control，AGC)单元(301)触发锁定接收信号后，将从各路天线(302)接收到的信号送入调制解调器(Modem)(303)中，在Modem中，首先是符号同步器(304)进行定位同步。符号同步器定位同步的结果为快速傅里叶变换(Fast Fourier Transformation，简称FFT)单元(305)提供一个参考点，从而能够进行接下来的一系列操作(比如，解调)。为不影响接下来的解调，符号同步定位精度必须在一定的合理范围之内。
符号定位同步就是确定OFDM符号的起始位置，即每个FFT窗口的起始位置。如附图2所示，符号定位同步可能出现四种情形：1)FFT窗口1(Window1)表示定时估计点是正确的，没有偏差，解调出来的数据也应该是正确的；2)FFT窗口2(Window2)表示定时估计点落在本符号的循环前缀(Cyclic Prefix，简称CP)内，并超前于最佳定时点；3)FFT窗口3(Window3)表示定时估计点落在下一个符号的循环前缀内，并滞后于最佳定时点；4)FFT窗口4(Window4)表示定时估计点落在前一个符号的数据部分内，并超前于本符号的循环前缀。
上述四种情况，第一种是理想情况，不会引起符号定位误差；第二种与理想点相差不大的情况下，引入的定位偏差可以通过均衡器进行恢复，但是如果相差较大时，会影响信道平滑的性能，从而降低均衡器的性能；第三种、第四种情况会引入ISI和ICI，会使系统性能出现大幅度下降，因此是要避免的。
在多径信道的情况下，很难定位在理想点上，因此需要确定一个合理的定位范围。首先根据信道平滑的点数确定允许的定位偏差，假设选用的平滑点数为11，在平滑的时候要保证这连续的11个点的相位是连续的，即所有频点的最大相位差不超过π。则允许的时间偏差Δt为
Figure PCTCN2018083072-appb-000001
在20MHz采样频率的情况下，时域上两点之间的时间间隔为50ns，Δf等于312.5kHz，因此Δt等于150ns，实际定位点的范围为超前或滞后理想定位点3个点，这样不会对平滑性能造成影响。
除此之外，多输入多输出系统(Multiple-Input Multiple-Output，简称MIMO)的情况下，每条天线存在固定的延时，在同步时不仅需要考虑多径，还需要考虑天线的固定延时。
因此，如何提供一种适用于多输入多输出系统的同步算法，在不影响定位精度的前提下降低计算的复杂度，是需要解决的问题
发明概述
以下是对本文详细描述的主题的概述。本概述并非是为了限制权利要求的保护范围。
本文所要解决的技术问题是提供一种信号同步方法及装置，能够在多输入多输出系统中保证接收信号同步时的定位精度，并且降低计算的复杂度。
本发明实施例提供一种信号同步方法，包括：
在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与 该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；
在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。
本发明实施例提供一种信号同步装置，包括：
粗同步模块，设置为在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；
精同步模块，设置为在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。
与相关技术相比，本发明实施例提供一种信号同步方法及装置，在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。本发明实施例能够在多输入多输出系统中保证接收信号同步时的定位精度，并且降低计算的复杂度。
在阅读并理解了附图和详细描述后，可以明白其他方面。
附图概述
图1为现有技术中数字接收机接收信号并进行解调的示意图；
图2为现有技术中符号定位同步的定位点示意图；
图3为本发明实施例1的一种信号同步方法的流程图；
图4为本发明实施例1中一种粗同步处理的框图示意图；
图5为本发明实施例1中延时触发粗同步检测的时序示意图；
图6为本发明实施例1中一种精同步处理的框图示意图；
图7为本发明示例1中利用AGC锁定时间延时触发粗同步检测示意图；
图8为本发明示例2中参考门限生成与粗同步检测触发的示意图；
图9为本发明实施例2的一种信号同步装置的示意图。
详述
为使本发明的目的、技术方案和优点更加清楚明白，下文中将结合附图对本发明的实施例进行详细说明。需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互任意组合。
实施例1
如图3所示，本发明实施例提供了一种信号同步方法，包括：
步骤S310，在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；
步骤S320，在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。
在一种实施方式中，所述对任意一路接收天线接收到的信号进行延时自相关处理，包括：
根据短训练序列的周期N对接收信号r(n)进行延时N拍的符号自相关运算，得到第一信号Λ(m)；
其中，所述延时N拍的符号自相关运算可以通过下述公式(2-1)表示：
Figure PCTCN2018083072-appb-000002
其中，N是所述短训练序列(Shorting Training Field，简称STF)的周期，如果采样频率是20MHz，则N等于16；r(n)为接收信号，r *(n)为接收信号的共轭；sign()是取符号函数；
其中，所述短训练序列用于信号检测、AGC功率调节、粗同步等，STF属于发送侧以及接收侧已知的一种序列，通过这种序列能够判断接收到的是什么信号，并能够为后续精同步处理提供一定的参考以及缓冲。
在一种实施方式中，所述第一时间长度是短训练序列的持续时间T1减去AGC单元锁定接收信号的最大时间T2 max后的时间长度；
其中，一般情况下，AGC单元锁定接收信号的时间t2不超过T2 max；
在一种实施方式中，每一路接收信号对应的参考门限是根据该路接收信号在一个短训练序列周期内的延时自相关结果取平均值后再乘以0.5得到的。
在一种实施方式中，将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步，包括：
如果一路处理后的接收信号达到该路接收信号对应的参考门限且持续一段时间均达到参考门限，则判定该路接收信号满足粗同步要求；
在至少存在一路接收信号满足粗同步要求时判定完成粗同步。
其中，所述持续保持时间为预设值，比如5个采样点；
在一种实施方式中，所述对任意一路接收信号进行本地互相关处理，包括：
根据长训练序列(Long Training Field，简称LTF)的周期N对接收信号r(m)进行本地互相关运算，得到第二信号Γ(m)；
其中，所述本地互相关运算可以通过下述公式(2-2)表示：
Figure PCTCN2018083072-appb-000003
其中，c(n)为滤波器的抽头系数，滤波器的抽头系数根据长训练序列的 数值进行设计；r *()为接收信号的共轭；
在一种实施方式中，将各路本地互相关处理的结果进行加权累加和滤波，包括：
将各路本地互相关处理的结果进行等权重累加获得第三信号；
将所述第三信号送入一个抽头数为a的滤波器中进行滤波；
其中，所述滤波器的抽头数a与接收信号采样间隔的乘积大于或等于发送天线间的最大延时；a个抽头系数中与第一发送天线发送信号对应的抽头系数的数值大于其他各个抽头系数的数值；除第一发送天线外的其他任意一根发送天线超前所述第一发送天线发送信号。
其中，从滤波后的信号中搜索最大值，最大值出现的位置就是LTF结束的位置，也是下一符号的开始，由于每个符号前面都有保护间隔，因此根据LTF结束的位置以及保护间隔的长度就可以确定每一个符号的起始位置，因此，在搜索到最大值时判定完成精同步。
在一种实施方式中，如图4所示，粗同步过程可以包括以下步骤：
1)在AGC单元锁定接收信号后，通过触发信号产生器(401)产生第一触发信号；
2)根据所述第一触发信号对各路接收天线(402)接收到的信号进行处理；
3)对接收信号分两路进行处理，其中一路信号送入取符号单元进行取符号运算，将取出的符号存入一个深度为N(N是STF的周期，比如，N＝16)的第一先入先出(First Input First Output，简称FIFO)缓存器(404)中，其中另一路信号送入取共轭单元(405)中进行取共轭运算；将第一FIFO缓存器的输出信号与取共轭单元的输出信号进行相乘运算；
4)将经过相乘运算的信号分成两路，其中一路信号存入一个深度为N(N是STF的周期，比如，N＝16)的第二先入先出(First Input First Output，简称FIFO)缓存器(406)中，其中另一路数据与第二FIFO缓存器的输出信号进行相减运算，相减后的信号送入累加取模单元(407)中进行累加取模运算，这样就完成一个窗口长度为N(N＝16)的延时自相关运算；
5)从AGC单元锁定接收信号开始，触发信号产生器(401)延时第一时间阈值T1后输出第二触发信号给均值运算单元(408)，所述均值运算单元提取一定窗口长度的延时自相关结果取平均得到参考门限值，同时触发粗同步检测；
6)每一路接收天线对应的比较单元(409)将累加取模单元输出的自相关结果与均值运算单元输出的参考门限进行比较得到1比特的比较结果；
7)将各路接收天线对应的比较单元(409)输出的1比特比较结果送入或逻辑运算单元(410)，产生1比特的粗同步结果；比如，当粗同步结果为1时，判定粗同步完成；
其中，如图5所示，比如，利用AGC锁定信号进行延时触发，提取一定窗口长度的延时自相关结果取平均得到门限值，同时触发粗同步检测，延时自相关的结果会依次与门限值进行比较，当出现一个点低于门限值时不会触发粗同步，只有延时自相关的结果连续5次低于门限值才会触发粗同步。因为粗同步检测不是从AGC锁定就开始的，而是得到参考门限开始的，这减少了AGC锁定到门限产生这段时间的粗同步检测，能够有效减少误同步的发生。
上述粗同步的目的是为了触发精同步计算，并为精同步提供一个合适的计算窗口长度。
在进行精同步过程中，利用长训练序列(Long Training Field，简称LTF)在一个周期内的数值大小设计一个抽头数为64的数字滤波器，接收信号经过该滤波器，实际上是与滤波器的抽头系数做互相关运算，所述互相关运算可以通过下述公式(2-2)进行表示：
Figure PCTCN2018083072-appb-000004
其中，N表示互相关计算的长度，N等于64；r(m)为接收信号，c(n)为滤波器的抽头系数；
其中，所述长训练序列LTF的周期是STF的4倍，与一个OFDM的周期相同，能够用来进行精同步、精频偏估计、信号估计。本发明实施例利用其具有很强的相关特性，在本地存储一段处理过的LTF(即滤波器的抽头系 数)，当接收信号与本地LTF相关上(出现峰值)，就认为同步上了。
在进行精同步的过程中，对于MIMO系统，由于除第一根天线外，其他天线会通过时域循环移位进行超前处理(最大超前为200ns，对于20MHz采样频率是4个点)，这导致MIMO系统不能简单地像单输入单输出(single-input single-Output，简称SISO)系统那样直接对互相关峰值检测就可以得到同步结果。对于MIMO，同步的结果必须是第一个峰值出现的位置。为了能够较为准确地定位到理想位置，本发明实施例通过对互相关的计算结果经过一个抽头数为6的滤波器，然后在一定范围内搜索滤波器输出结果的最大值，即为最终的精同步的结果。
另外，由附图2可知，同步位置有可能出现第三种情况，也即定时估计点落在下一个符号的循环前缀内，并滞后于最佳定时点，所以通过定位偏移处理可以提高定位同步的动态范围。比如，将同步位置向前移动6个点开始提取每个OFDM符号，在进行FFT之前，将该符号的前六个点的数值移动到符号最后的位置，这样可以允许定位点可以在最佳定位点左右摆动。这样既保证了定位同步点可以在最佳定位点左右移动，又不会引入符号间干扰，提高了定位同步的动态范围。
在一种实施方式中，基于上述考虑，如图6所示，精同步过程可以包括下述步骤：
1)粗同步完成触发信号产生器(601)，所述触发信号产生器产生第三触发信号(相当于在AGC锁定时刻后延时T2时间)；
2)根据所述第三触发信号将各路接收天线接收到的信号送入对应的各路第一滤波器(602)中进行滤波处理，然后再送入各自对应的取模单元(603)中进行取模处理；
其中，滤波器的抽头系数是根据长训练序列的时域信号进行相应处理的，首先对长训练序列的时域信号取符号后确定滤波器抽头系数的符号，然后根据长训练序列的时域信号幅值的大小，将滤波器系数设置为0、1、2，因为幅值大抗噪声能力强，置信度高，因此给予一个较大的权重。这样滤波器的抽头系数c(n)是由0、1、2组成的复数(比如，1+2i)；
3)将各天线取模后的信号送入一个累加器(604)中进行求和运算，相当于对各个天线互相关运算结果等权重叠加；
4)将累加器输出的信号输入到一个第二滤波器(605)中进行处理，所述处理用于降低多天线不同延时以及多径的影响；
其中，第二滤波器相当于是一个滑窗求和，对其中的一个值进行了加权，滑窗能够降低天线不同延时以及多径的影响，加权能够提高第一根发送天线的峰值强度，有利于定位到第一根天线的峰值，提高定位结果的准确性。
5)将第二滤波器的输出信号输入到最大值搜索单元(606)中进行最大值搜索，得到精同步结果；
6)将最大值搜索单元输出的结果输入到定位偏移单元(607)中，将同步位置向前移动6个点开始提取每个OFDM符号，在进行FFT之前，将该符号的前六个点的数值移动到符号最后的位置，定位偏移后得到提取FFT窗口的起始位置；另外，定位偏移的点在提取完数据后利用符号的周期特性移到符号最后。
下面通过一些示例对粗同步过程和精同步过程中的处理进行进一步的描述。
示例1
如图7所示，AGC锁定后，接收信号进入modem。此时不会立即进行粗同步检测，而是延时一定的时间才进行检测。延时的时间(T)是通过用于进行粗同步的短训练序列结束的时间(702)减去AGC最晚锁定的时间(701)得到的。
而在实际工作中，AGC锁定(703)后，经过延时时间(T)得到门限(704)，这使粗同步检测(705)发生在门限产生之后。这使AGC锁定(703)后，粗同步检测(705)触发之前不会进行粗同步检测，这会有效减少误同步的发生。
示例2
如图8所示，接收信号经过延时自相关处理得到输出结果(801)，利用这个输出结果(801)由AGC锁定延时触发开始计算门限值(802)，门限值的计算从触发开始提取输出结果(801)的16个值然后取平均得到，门限值计算完成后，门限值开始生效，粗同步检测开始进行，然后输出结果(801)与门限值通过比较器(803)进行比较并输出1比特的比较结果，比较结果经过一个抽头系数全为1的5抽头滤波器(804)，滤波器的输出数据与寄存器中的值(805)进行比较，其中，寄存器中的值设置为5，比较结果相等证明该天线粗同步被检测到；所述5抽头滤波器(804)的作用在于：要连续5个点达到门限值才认为是粗同步触发。
所有天线的粗同步检测结果通过逻辑运算或(806)进行处理，即只要有一条天线粗同步被检测到，粗同步过程就完成。
粗同步完成将会触发精同步计算及检测。
示例3
如图6所示，根据长训练序列的时域值设计第一滤波器(602)的抽头系数，分别对长训练序列时域值的实部与虚部分别求平均值，将平均值除以2得到门限值，长训练序列时域值的实部与虚部分别除以其对应的门限值，然后对计算结果进行四舍五入取整(绝对值超过2的取2)得到最终滤波器的抽头系数c'(n)。
Figure PCTCN2018083072-appb-000005
Figure PCTCN2018083072-appb-000006
在上述公式(3-1)中，c(n)是对原始LTF的时域信号进行压缩，即用很小的比特表示LTF的时域信号的特性，X(n)是LTF时域信号，N＝64代表LTF的周期，round()是取整函数；
在上述公式(3-2)中，c'(n)是抽头系数(即本地存储的长训练序列)；
对于第二滤波器(605)，第二滤波器一共有6个抽头，抽头系数为：{1,1,1,1,2,1}，利用第二滤波器能够抵抗多径效应以及不同天线之间的延时，同时利用提高第一条接收天线峰值的权重值，使同步结果定位在第一条接收天线上。
如图9所示，本发明实施例提供了一种信号同步装置，包括：
粗同步模块901，设置为在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；
精同步模块902，设置为在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。
在一种实施方式中，粗同步模块，设置为采用以下方式对任意一路接收天线接收到的信号进行延时自相关处理：
根据短训练序列的周期N对接收信号r(n)进行延时N拍的符号自相关运算，得到第一信号Λ(m)；
其中，所述延时N拍的符号自相关运算可以通过下述公式表示：
Figure PCTCN2018083072-appb-000007
其中，N是所述短训练序列STF的周期，r(n)为接收信号，r *(n)为接收信号的共轭；sign()是取符号函数。
在一种实施方式中，所述第一时间长度是短训练序列的持续时间T1减去AGC单元锁定接收信号的最大时间T2 max后的时间长度。
在一种实施方式中，每一路接收信号对应的参考门限是根据该路接收信号在一个短训练序列周期内的延时自相关结果取平均值后再乘以0.5得到 的。
在一种实施方式中，粗同步模块，设置为采用以下方式将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步：
如果一路处理后的接收信号达到该路接收信号对应的参考门限且持续一段时间均达到参考门限，则判定该路接收信号满足粗同步要求；
在至少存在一路接收信号满足粗同步要求时判定完成粗同步。
在一种实施方式中，精同步模块，设置为采用以下方式对任意一路接收信号进行本地互相关处理：
根据长训练序列的周期N对接收信号r(m)进行本地互相关运算，得到第二信号Γ(m)；
其中，所述本地互相关运算可以通过下述公式表示：
Figure PCTCN2018083072-appb-000008
其中，c(n)为滤波器的抽头系数，滤波器的抽头系数根据长训练序列的数值进行设计；r *()为接收信号的共轭。
在一种实施方式中，精同步模块，设置为采用以下方式将各路本地互相关处理的结果进行加权累加和滤波：
将各路本地互相关处理的结果进行等权重累加获得第三信号；
将所述第三信号送入一个抽头数为a的滤波器中进行滤波；
其中，所述滤波器的抽头数a与接收信号采样间隔的乘积大于或等于发送天线间的最大延时；a个抽头系数中与第一发送天线发送信号对应的抽头系数的数值大于其他各个抽头系数的数值；除第一发送天线外的其他任意一根发送天线超前所述第一发送天线发送信号。
工业实用性
本发明实施例提供的技术方案，在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长 度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。本发明实施例能够在多输入多输出系统中保证接收信号同步时的定位精度，并且降低计算的复杂度。

Claims (14)

  1. 一种信号同步方法，包括：
    在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；
    在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号中搜索最大值，在搜索到最大值时判定完成精同步。
  2. 如权利要求1所述的方法，其中：
    所述对任意一路接收天线接收到的信号进行延时自相关处理，包括：
    根据短训练序列的周期N对接收信号r(n)进行延时N拍的符号自相关运算，得到第一信号Λ(m)；
    其中，所述延时N拍的符号自相关运算通过下述公式表示：
    Figure PCTCN2018083072-appb-100001
    其中，N是所述短训练序列STF的周期，r(n)为接收信号，r *(n)为接收信号的共轭；sign()是取符号函数。
  3. 如权利要求1或2所述的方法，其中：
    所述第一时间长度是短训练序列的持续时间T1减去AGC单元锁定接收信号的最大时间T2 max后的时间长度。
  4. 如权利要求2所述的方法，其中：
    每一路接收信号对应的参考门限是根据该路接收信号在一个短训练序列周期内的延时自相关结果取平均值后再乘以0.5得到的。
  5. 如权利要求1所述的方法，其中：
    将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步，包括：
    如果一路处理后的接收信号达到该路接收信号对应的参考门限且持续一段时间均达到参考门限，则判定该路接收信号满足粗同步要求；
    在至少存在一路接收信号满足粗同步要求时判定完成粗同步。
  6. 如权利要求1所述的方法，其中：
    所述对任意一路接收信号进行本地互相关处理，包括：
    根据长训练序列的周期N对接收信号r(m)进行本地互相关运算，得到第二信号Γ(m)；
    其中，所述本地互相关运算通过下述公式表示：
    Figure PCTCN2018083072-appb-100002
    其中，c(n)为滤波器的抽头系数，滤波器的抽头系数根据长训练序列的数值进行设计；r *()为接收信号的共轭。
  7. 如权利要求1所述的方法，其中：
    将各路本地互相关处理的结果进行加权累加和滤波，包括：
    将各路本地互相关处理的结果进行等权重累加获得第三信号；
    将所述第三信号送入一个抽头数为a的滤波器中进行滤波；
    其中，所述滤波器的抽头数a与接收信号采样间隔的乘积大于或等于发送天线间的最大延时；a个抽头系数中与第一发送天线发送信号对应的抽头系数的数值大于其他各个抽头系数的数值；除第一发送天线外的其他任意一根发送天线超前所述第一发送天线发送信号。
  8. 一种信号同步装置，包括：
    粗同步模块，设置为在自动增益控制AGC单元锁定接收信号时对各路接收天线接收到的信号进行延时自相关处理，在延时第一时间长度后将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步；
    精同步模块，设置为在粗同步完成后，对各路接收信号进行本地互相关处理，将各路本地互相关处理的结果进行加权累加和滤波，从滤波后的信号 中搜索最大值，在搜索到最大值时判定完成精同步。
  9. 如权利要求8所述的装置，其中：
    粗同步模块，设置为采用以下方式对任意一路接收天线接收到的信号进行延时自相关处理：
    根据短训练序列的周期N对接收信号r(n)进行延时N拍的符号自相关运算，得到第一信号Λ(m)；
    其中，所述延时N拍的符号自相关运算通过下述公式表示：
    Figure PCTCN2018083072-appb-100003
    其中，N是所述短训练序列STF的周期，r(n)为接收信号，r *(n)为接收信号的共轭；sign()是取符号函数。
  10. 如权利要求8或9所述的装置，其中：
    所述第一时间长度是短训练序列的持续时间T1减去AGC单元锁定接收信号的最大时间T2 max后的时间长度。
  11. 如权利要求9所述的装置，其中：
    每一路接收信号对应的参考门限是根据该路接收信号在一个短训练序列周期内的延时自相关结果取平均值后再乘以0.5得到的。
  12. 如权利要求8所述的装置，其中：
    粗同步模块，设置为采用以下方式将各路处理后的接收信号与该路接收信号对应的参考门限进行比较，根据各路比较结果确定是否完成粗同步：
    如果一路处理后的接收信号达到该路接收信号对应的参考门限且持续一段时间均达到参考门限，则判定该路接收信号满足粗同步要求；
    在至少存在一路接收信号满足粗同步要求时判定完成粗同步。
  13. 如权利要求8所述的装置，其中：
    精同步模块，设置为采用以下方式对任意一路接收信号进行本地互相关处理：
    根据长训练序列的周期N对接收信号r(m)进行本地互相关运算，得到 第二信号Γ(m)；
    其中，所述本地互相关运算通过下述公式表示：
    Figure PCTCN2018083072-appb-100004
    其中，c(n)为滤波器的抽头系数，滤波器的抽头系数根据长训练序列的数值进行设计；r *()为接收信号的共轭。
  14. 如权利要求8所述的装置，其中：
    精同步模块，设置为采用以下方式将各路本地互相关处理的结果进行加权累加和滤波：
    将各路本地互相关处理的结果进行等权重累加获得第三信号；
    将所述第三信号送入一个抽头数为a的滤波器中进行滤波；
    其中，所述滤波器的抽头数a与接收信号采样间隔的乘积大于或等于发送天线间的最大延时；a个抽头系数中与第一发送天线发送信号对应的抽头系数的数值大于其他各个抽头系数的数值；除第一发送天线外的其他任意一根发送天线超前所述第一发送天线发送信号。
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101534280A (zh) * 2009-04-15 2009-09-16 大唐微电子技术有限公司 一种定时同步接收方法及其装置
US20120189085A1 (en) * 2008-11-19 2012-07-26 Qualcomm Atheros, Inc. Multi-symbol phase offset estimation
CN103200144A (zh) * 2013-03-28 2013-07-10 灵芯微电子科技（苏州）有限公司 一种用于mimo-ofdm系统的同步方法

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US7613104B2 (en) * 2006-05-31 2009-11-03 Nokia Corporation Method, apparatus and computer program product providing synchronization for OFDMA downlink signal

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120189085A1 (en) * 2008-11-19 2012-07-26 Qualcomm Atheros, Inc. Multi-symbol phase offset estimation
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CN103200144A (zh) * 2013-03-28 2013-07-10 灵芯微电子科技（苏州）有限公司 一种用于mimo-ofdm系统的同步方法

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