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OFDM parameter estimation

短训练符号 整数频偏 倍频-载波估计 ofdm参数估计 ofdm-symbol

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代码分类: 仿真计算

开发平台: matlab

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代码描述

中文说明:

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。


English Description:

Firstly, according to the characteristics of the short training word, the correlation operation is carried out to detect the signal arrival. When the correlation value is greater than the threshold for a certain number of times, the signal arrival is considered. Then, according to the characteristics of the long training word, the correlation operation is carried out to estimate the starting position of the FFT window of the OFDM symbol. After estimating the position of the FFT window, the small frequency offset is estimated in the time domain. The two long training words are compensated for the small frequency offset, and then the FFT operation is performed. According to the result of the FFT operation, the integer multiple frequency offset is estimated. After these parameters are estimated, the data can be demodulated. Firstly, complete frequency offset compensation is carried out for the data part, and then FFT operation is carried out according to the estimated FFT window position to obtain the frequency domain data and demodulate it. Then, the pilot information is extracted from the subcarrier position corresponding to the pilot. According to the pilot information, the remaining timing error and the remaining channel response error are estimated, and the error is sent to the loop for tracking. When all the data are received, it will return to the signal arrival detection state again, and carry out the next signal arrival detection and signal reception


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OFDM完整版

..........\ofdm_mod.m

..........\v06_03_dem_2up_arrange.m