基于循环前缀相关性的水声OFDM信号调制识别方法*

本文研究水声OFDM通信信号与常见单载波水声数字通信信号(MPSK,MFSK)之间的调制识别问题。考虑到水声信道复杂传播特性对循环前缀相关性的影响,本文通过截取信号前后片段并迭代搜索双相关峰进行无需先验知识的水声OFDM通信信号特征参数提取,在此基础上设计了一种基于模糊系统的水声OFDM通信信号识别器。对不同信道条件下海上实录信号数据的识别实验结果表明了本文方法的有效性。

Modulation recognition of underwater acoustic OFDM signals based on the correlation property of the cyclic prefix*

In view of the rapidly developing OFDM underwater acoustic communication technology and its application systems, this paper investigates the problem of discriminating orthogonal frequency division multiplexing(OFDM) from common single-carrier digital underwater acoustic communication signals(MPSK,MFSK) over underwater acoustic channels. Considering the correlation characteristics of the cyclic prefix (CP) at the presence of the doubly selective underwater acoustic channels, an iterative dual-peak searching strategy is proposed to extract the CP correlation peak feature, that do not need any prior knowledge, as the input vector of a fuzzy recognition system for modulation recognition of OFDM signals. The experimental modulation classification results obtained with field signals at 3 different underwater acoustic channels show that the proposed modulation recognition method has good classification performance.