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随着第五代移动通信技术、低轨卫星互联网等通信系统的发展，正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)技术凭借良好的频谱效率得到日益广泛的应用。但OFDM系统信号参数复杂，对非合作条件下的盲信号分析带来了较大困难，需要在尽可能少的先验信息下，判定信号参数。为此，提出了一种基于相位轨迹特征的OFDM信号盲分析方法，利用OFDM信号固有的循环周期性，粗估计子载波数及子载波间隔，在此基础上通过非线性变换等处理获取子载波间及符号间的相位变化轨迹，基于相位变化轨迹分析其反映的采样定时误差、载波频率偏差等参数信息并修正估计值，最终通过信号接收误码率进行估计参数正确性验证，实现了对OFDM信号盲分析。仿真分析结果表明，在信噪比(SNR)大于8 dB时，即可实现参数准确估计，优于利用先验信息的相关处理方法。
Abstract：With the development of 5th Generation Mobile Communication Technology(5G), low-orbit satellite Internet and other communication systems, Orthogonal Frequency Division Multiplexing(OFDM) has been increasingly used due to its good spectral efficiency. However, the OFDM signal has complicated parameters, which brings great difficulty to the blind signal analysis under non-cooperative conditions. And it is necessary to determine the signal parameters with as little prior information as possible. Therefore, a blind analysis method of OFDM signal based on phase trajectory is proposed. The number of subcarriers and the interval of subcarriers are roughly estimated by using inherent periodic characteristics of the signal, and then the phase variation trajectory between the subcarriers and symbols is obtained based on the nonlinear transformation and the sampling timing error and carrier frequency offset are estimated and modified in detail based on phase trajectory. Finally, the correctness of the estimated parameters is verified by the bit error rate of the received signal. The OFDM parameters are analyzed without prior information. The simulation results show that when the SNR is greater than 8 dB, the parameters can be accurately estimated, which is superior to the correlation method using prior information.
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基本信息:
DOI：
中图分类号:TN929.53
引用信息:
[1]史飞,陶丽红,闫红超等.一种基于相位轨迹的OFDM信号盲分析方法[J].无线电工程,2023,53(06):1403-1408.
基金信息:
国家自然科学基金(U20B2071)~~