基于混沌正交组合序列的M元码分多址水声通信
M-ary code division multiple access underwater acoustic communication based on chaotic orthogonal combination sequence

提出了M元能量检测器算法，该算法简单易实现，极大优化了M元码分多址系统接收机结构和解码运算量。同时，M元能量检测器具有抗载波相位跳变和抗水声信道多途干扰的能力。针对M元码分多址水声通信系统中所需扩频序列数量庞大、选码难度高的问题，提出了混沌正交组合序列，通过简单的迭代组合即可产生大量满足要求的扩频序列，而且同族的混沌正交组合序列间满足正交关系。海试试验成功实现了7个用户的M元码分多址水声通信试验（M=512），共采用了3 584条混沌正交组合序列，每个用户通信速率为70 bit·s-1，验证了算法的有效性，为网络化水声通信的应用提供了技术基础。
An M-ary energy detector algorithm is proposed. The algorithm is simple and easy to implement, which greatly optimizes the receiver structure and decoding operation of the M-ary code division multiple access (CDMA) system. Also, the M-ary energy detector has the ability to resist carrier phase hopping and multi-channel interference in underwater acoustic channels. To solve the problem of selecting a large number of spreading sequences in M-ary CDMA underwater acoustic communication system, a chaotic orthogonal combination sequence is proposed in this paper, and a large number of spreading sequences satisfying the requirements can be generated through a simple combination of iterations. And, the orthogonal relationship exists between the chaotic orthogonal combination sequences of the same family. In January 2015, a sea trial successfully implemented the M-ary code CDMA Acoustic Communication Test (M=512) for 7 users with a total of 3 584 chaotic orthogonal combination sequences and a communication rate of 70 bit·s-1, which verifies the validity of the proposed algorithm and provides a technical basis for the application of networked underwater acoustic communications.