基于Chebyshev混沌序列的正交宽带调制解调方法

针对常规的相干解调和非相干解调在水声信道通信中可靠性差的问题,文中提出了一种基于Chebyshev混沌序列的正交宽带调制解调方法。该方法基于海洋水声信道环境与传播特点,采用统计特性接近环境噪声且具有尖锐自相关、宽带特性的Chebyshev混沌序列作为信息载体和同步信号,并利用欧氏距离分类器对接收信号进行非相干分类判决解调。该方法可有效抑制水声信道因多途传播而引起的频率选择性衰落和码间干扰,从而更好地实现低信噪比条件下可靠水声通信。仿真实验证明,在-10 dB以上信噪比环境下,文中所提通信方法在具有多途效应的水声信道上具有良好的通信性能。

The Orthogonal Wideband Signal Modulation and Demodulation Method Based on Chebyshev Bhaotic Sequence

An orthogonal wideband signal modulation and demodulation method based on Chebyshev chaotic sequence is proposed in this paper to improve the reliability of underwater acoustic communication. The method is based on the environment and propagation characteristics of ocean underwater acoustic channel. The statistical properties of Chebyshev chaotic sequence are close to environmental noise, and it has sharp autocorrelation and broadband characteristics. Based on the properties, Chebyshev chaotic sequence is used as information carrier and synchronization signal in the proposed method. The received signal is demodulated by Euclidean distance classifier. Experimental results show that the method effectively suppresses the frequency selective fading and inter-symbol interference caused by multi-path propagation of the underwater acoustic channel, and achieves reliable underwater acoustic communication under low SNR conditions. The simulation results verify that the communication method has good communication performance on the underwater acoustic channel with multipath effect in the signal-to-noise ratio environment above -10 dB.