Description: 一种基于PN训练序列的OFDM时频同步的新算法。通过构造倒序结构的同步训练序列，获得了较好的定时性能。-PN training sequence based on the OFDM time-frequency synchronization of the new algorithm. By constructing a reverse structure synchronization training sequence, to obtain a better performance from time to time. Platform: |
Size: 116736 |
Author:fisher |
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Description: In this paper, we investigate the timing and carrier
frequency offset (CFO) synchronization problem in decode and
forward cooperative systems operating over frequency selective
channels. A training sequence which consists of one orthogonal
frequency-division multiplexing (OFDM) block having a tile
structure in the frequency domain is proposed to perform synchronization.
Timing offsets are estimated using correlation-type
algorithms. By inserting some null subcarriers in the proposed tile
structure, we propose a computationally efficient subspace decomposition-
based algorithm for CFO estimation. The issue of optimal
tile length is studied both theoretically and through simulations.
By judiciously designing the tile size of the pilot, the proposed
algorithms are shown to have better performance, in terms of
synchronization errors and bit error rate, than the time-division
multiplexing-based training method and the computationally demanding
space-alternating generalized expectation-maximization Platform: |
Size: 985088 |
Author:ashish |
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Description: In this paper, we investigate the timing and carrier
frequency offset (CFO) synchronization problem in decode and
forward cooperative systems operating over frequency selective
channels. A training sequence which consists of one orthogonal
frequency-division multiplexing (OFDM) block having a tile
structure in the frequency domain is proposed to perform synchronization.
Timing offsets are estimated using correlation-type
algorithms. By inserting some null subcarriers in the proposed tile
structure, we propose a computationally efficient subspace decomposition-
based algorithm for CFO estimation. The issue of optimal
tile length is studied both theoretically and through simulations.
By judiciously designing the tile size of the pilot, the proposed
algorithms are shown to have better performance, in terms of
synchronization errors and bit error rate, than the time-division
multiplexing-based training method and the computationally demanding
space-alternating generalized expectation-maximization Platform: |
Size: 728064 |
Author:ashish |
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Description: 一种基于PN训练序列的OFDM时频同步的新算法。通过构造倒序结构的同步训练序列-PN training sequence based on the OFDM time and frequency synchronization of the new algorithm. Structure by constructing a reverse synchronization of training sequences Platform: |
Size: 4096 |
Author:tianyu |
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Description: 这是用SIMULINK的S-FUNCTION方式编写的系统仿真代码，系统是基于4G网络的核心技术空时分组编码的MIMO-OFDM通信系统的，涉及到空间分集、时间分集和频率分集的有机结合，包括QPSK调制解调、IFFT调制、控制编解码、基于训练符号的信道估计等通信模块。包括main_STBC_MIMO_OFDM和training_symbol两个M文件和一个DOC文件，对各部分的都有详细的代码和注释。-It is used SIMULINK the S-FUNCTION approach to the preparation of the system simulation code, the system is based on the 4G network s core technology space-time block coded MIMO-OFDM communication system, involving spatial diversity, time diversity and frequency diversity of the organic combination, including QPSK modulation and demodulation, IFFT modulation, control of encoding and decoding, symbol-based channel estimation training and other communication module. Including main_STBC_MIMO_OFDM and training_symbol two M file and a DOC file, have detailed the various parts of the code and comments.
Platform: |
Size: 13312 |
Author:masong |
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Description: 首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。-First of all, according to the characteristics of the short training word correlation calculation of the signal reaching the detector, when the detected correlation value is greater than the threshold of a certain frequency and that a signal arrives. Then, the correlation calculation according to the characteristics of the long training word, the initial estimate of the location of the OFDM symbol FFT window. The estimated position of the FFT window, the first small frequency offset estimation in the time domain, the small frequency offset compensation, the two long training word FFT operation integer frequency offset estimate, according to the result of the FFT operation. After the completion of these parameter estimates, data demodulation. The complete frequency offset compensation, and then based on the estimated FFT window position for the FFT operation to obtain a frequency domain data, demodulates the first data part. Then in a position corresponding to the pilot subcarriers extr Platform: |
Size: 124928 |
Author:章田 |
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Description: 首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。-First, according to the characteristics of the short training word correlation operation, the signal reaching the detector, when the detected correlation value is greater than the threshold after a certain number of times that a signal arrives. And then the characteristics of long training word, the correlation operation for the FFT window starting position of an OFDM symbol estimate. The estimated position of the FFT window, the first small frequency offset in the time domain estimation, the two long training word small frequency offset compensation, the FFT operation, the FFT result of the operation for integer frequency offset estimate. These parameter estimation is completed, the data can be demodulated on. The first portion of the data for a complete frequency offset compensation, and based on the estimated FFT window position of the FFT operation to obtain frequency domain data, demodulated. Then corresponding to the position of the pilot subcarriers are extracted on pilot inform Platform: |
Size: 11264 |
Author:wangkai |
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Description: Spectrally Efficient Time-Frequency Training
OFDM for Mobile Large-Scale MIMO Systems Platform: |
Size: 547840 |
Author:NINU RACHEL PHILIP |
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Description: A Novel Time and Frequency Synchronization Scheme for OFDM Systems
A new training symbol is designed and a novel
time and frequency synchronization scheme for orthogonal frequency division multiplexing systems is proposed. The time synchronization is accomplished by using the symmetric conjugate of the training symbol in time domain and the frequency synchronization is finished by utilizing the good
autocorrelation of the training symbol in frequency domain.
The simulation results show that compared with conventional schemes, the proposed scheme gives a more accurate estimate of symbol timing and carrier frequency offset and provides a
wider acquisition range for the carrier frequency offset.1 Platform: |
Size: 321536 |
Author:Mohamed |
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Description: Time and Frequency Synchronization Techniques for
OFDM Systems operating in Gaussian and Fading
Channels: A Tutorial
The aim of this paper is to survey and compare
previous methods for Data-aided timing and frequency
synchronization of OFDM System. In the sequel, we propose a fast
and accurate FFT-based frequency offset estimation. The
synchronization techniques are examined in Gaussian andMultipath fading environments for comparison. The results of the
performance comparison are presented in terms of mean andmean-square error (MSE) obtained by simulations. The timing
offset estimator with best performance is chosen for system timingsynchronization. The FFT-based frequency offset estimation
method has significantly smaller MSE than others can beperformed using the same timing training symbol. Therefore,there is only one training symbol needed as preamble in whole
synchronization process.
Platform: |
Size: 340992 |
Author:Mohamed |
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Description: 接收端采用的算法和程序流程与发送端发送的OFDM符号的帧结构有关系。具体的帧结构，以及定时估计，频偏估计，剩余误差跟踪的算法可参考算法说明文档。这里对程序的流程进行说明。
首先根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。
-The receiving end uses the algorithm and the program flow and the frame structure of the OFDM symbol transmitted by the sending end. Specific frame structure, and timing estimation, frequency offset estimation, residual error tracking algorithm can refer to the documentation. Here to illustrate the process of the program.
First, according to the characteristics of the short training word correlation operation, the signal reaches the detection, when the correlation value is greater than the threshold of a certain number of times, that there is a signal to reach. Then, according to the characteristics of the long training word, the correlation operation is carried out, and the initial position of the OFDM symbol FFT is estimated. The estimated position of the FFT window, first in the time domain for small frequency offset estimation, two long training word for small frequency offset compensation, the FFT operation. According to the result of FFT for integer frequency bias estimation. Af Platform: |
Size: 34816 |
Author:shinfer |
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Description: 搭建OFDM通信系统的框架，包含特征值与特征向量的提取、训练样本以及最后的识别，用于时频分析算法，现代信号处理中谱估计在matlab中的使用，有均匀线阵的CRB曲线，基于chebyshev的水声信号分析，加入重复控制，最大信噪比的独立分量分析算法。- Build a framework OFDM communication system, Contains the eigenvalue and eigenvector extraction, the training sample, and the final recognition, For time-frequency analysis algorithm, Modern signal processing used in the spectral estimation in matlab, There ULA CRB curve, Based chebyshev underwater acoustic signal analysis, Join repetitive control, SNR largest independent component analysis algorithm. Platform: |
Size: 11264 |
Author:npadutdpy |
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Description: 完美的OFDM程序，根据短训练字的特性进行相关运算，进行信号到达检测，当检测到相关值大于门限一定次数后，认为有信号到达。然后根据长训练字的特性，进行相关运算，进行OFDM符号FFT窗口起始位置的估计。估计出FFT窗口的位置后，先在时域进行小频偏的估计，将两个长训练字进行小频偏补偿后，进行FFT运算，根据FFT运算的结果进行整数倍频偏的估计。这些参数估计完成后，就可以进行数据解调了。先对数据部分进行完整的频偏补偿，然后根据估计的FFT窗口位置进行FFT运算得到频域的数据，进行解调。然后在对应于导频的子载波位置上提取出导频信息，根据导频信息估计出剩余定时误差以及剩余的信道响应误差，将误差量送入环路进行跟踪。当收到所有数据后，重新回到信号到达检测状态，进行下一次信号到达的检测和信号接收。-Perfect OFDM procedures, according to the characteristics of the short training word correlation operation, the signal reaching the detector, when the detected correlation value is greater than a certain threshold number of times that the signal arrives. Then according to the characteristics of the long training words, the correlation operation, to estimate the OFDM symbol FFT window starting position. The estimated position of the FFT window, the first in the time domain frequency offset estimate small, two small words long training frequency offset compensation after FFT operation, estimated integer frequency offset based on the result of the FFT operation. These parameter estimation is completed, the data can be demodulated. The first portion of the data of the complete frequency offset compensation, and then performs the FFT operation to obtain data in the frequency domain, demodulates the estimated FFT window position. Then extract the subcarrier corresponding to the pilot positio Platform: |
Size: 692224 |
Author:Jieni ZHANG |
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Search - Time Frequency Training OFDM