An Algorithm for Recognition and Parameters Estimation of OFDM in Alpha Stable Distribution Noise
ZHANG Jun-lin1, WANG Bin1, WANG Yang1, LIU Ming-qian2
1. School of Information Systems Engineering, PLA Information Engineering University, Zhengzhou, Henan 450001, China;
2. State Key Laboratory of Integrated Service Networks, Xidian University, Xi'an, Shaanxi 710071, China
摘要 正交频分复用（OFDM，Orthogonal Frequency Division Multiple）信号的调制识别与参数估计是非协作通信领域的重要研究内容.为了解决α稳定分布噪声下OFDM信号调制识别与参数估计困难的问题，提出一种广义循环平稳的盲处理算法.该算法首先对接收信号进行非线性变换，推导出接收信号的广义循环自相关函数表达式，分析了单载波调制信号与OFDM信号的广义循环自相关函数特性，并给出了OFDM信号的广义循环自相关函数与待估参数之间的关系.然后，基于分析结论，利用广义循环自相关函数构造调制识别特征完成OFDM信号与单载波信号的调制方式自动分类；最后，针对OFDM信号的调制参数估计问题，提出了一种基于广义循环自相关函数的调制参数估计算法.理论分析与仿真结果表明，在α稳定分布噪声环境下，该算法可以有效实现OFDM信号调制识别与参数估计，且算法不依赖接收信号的先验信息，可以直接对中频接收信号进行处理.
Abstract：Automatic modulation recognition and parameter identification of orthogonal frequency division multiplexing (OFDM) play a vital role in the field of non-cooperative communication applications.A blind recognition and parameter identification called generalized cyclostationarity algorithm is proposed for OFDM in alpha stable distribution noise.Firstly,the received signal is mapped by nonlinear transformation,the analytical expressions for the generalized cyclic autocorrelation function are derived,and the generalized cyclostationarity characteristics of single carrier linear digital (SCLD) modulations and OFDM are investigated.Then,the recognition feature is structured based on generalized cyclic autocorrelation function to recognize OFDM versus SCLD signals.Finally,for the problem of blind parameter identification for OFDM,an algorithm based on generalized cyclic autocorrelation function is presented.Theoretical analysis and simulation results demonstrate the effectiveness of the proposed algorithm in alpha stable distribution noise.Furthermore,this algorithm obviates the need for signal preprocessing tasks,such as symbol timing estimation,carrier and waveform recovery.
张俊林, 王彬, 汪洋, 刘明骞. 一种α稳定分布噪声下OFDM信号调制识别与参数估计算法[J]. 电子学报, 2018, 46(6): 1390-1396.
ZHANG Jun-lin, WANG Bin, WANG Yang, LIU Ming-qian. An Algorithm for Recognition and Parameters Estimation of OFDM in Alpha Stable Distribution Noise. Acta Electronica Sinica, 2018, 46(6): 1390-1396.
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2018, Vol. 46 
