时变水声环境中的信道均衡技术研究

For the demand of high speed reliable underwater acoustic communications under adverse conditions such as severe channel time-varying, multipath extended and signal fluctuation fading, physical characteristics of underwater acoustic vector field and its engineering application are combined scientifically in this proposal. ① For the obstacles brought by the dynamic fluctuation of underwater acoustic channel to high reliable coherent communication, correlation properties of time-varying vector channel is analyzed. The physical infrastructure and methods to address the problem of underwater communications over a time-varying channel is explored by using of space diversity gain from vector channel. ② According to the correlation properties of noise vector field, multichannel space diversity technology based on vector sensor is on the research, and it can effective control the worse influence of environment noise on remote communication quality. ③ In view of the contradiction between the multipath propagation and high rate communication, adaptive multichannel decision feedback equalizer is put forward based on the vector (array), which can realize the high speed communication in time-varying environment by overcome worse intersymbol interference and waveform distortion adaptively. . This project proposed new ideas and theoretical basis to achieve long distance, high speed and high reliability underwater acoustic communication under actual time-varying underwater acoustic environment. Theoretical and simulation work is conducted and experimental research is developed. The work of the proposal will provides a theoretical basis and necessary technical support for developing the robust underwater acoustic communication system.

面向信道时变、多途扩展严重、信号起伏衰落恶劣条件下的高速、远程、可靠水声通信需求，本项目将水声矢量场物理特性理论基础与工程技术应用相结合：① 针对水声信道动态起伏为实现可靠水下通信带来的障碍，分析时变矢量通信信道的相关特性，探索利用矢量信道的分集输出，抑制信道起伏对通信系统影响的物理基础和途径；② 针对噪声对远程通信的影响，分析噪声矢量场的相关特性，矢量噪声场的弱相关特性和多通道的空间分集合并，有效的抑制了噪声对远程通信质量的影响；③ 针对多途扩展与高速率通信之间的矛盾，提出基于矢量（阵）的自适应多通道判决反馈均衡器，可自适应克服时变码间干扰的同时，避免信道估计误差对通信性能的影响，提高通信速率。.本课题为解决实际时变水声环境下兼顾远距离、高速率、高可靠的水声通信提出新思路和理论依据，开展水下实验，验证方法并改进性能。为增强通信系统对水下环境的适应能力，发展稳健水声通信系统奠定基础。

本课题面向信道时变、多途扩展严重、信号起伏衰落恶劣条件下的高速、远程、可靠水声通信需求展开研究工作。.根据水声信道特性建立了时变水声信道物理模型、矢量信道物理模型和时变矢量信道物理模型，分析了时变矢量信道多途结构及矢量信号场、噪声场的相关特性；针对多途扩展与高速率通信之间的矛盾，分析了随机时变矢量水声信道的特性。基于单矢量传感器开展了自适应多通道判决反馈均衡、分数间隔判决反馈均衡、单矢量时反自适应判决反馈均衡、单矢量双向判决反馈均衡等方法的研究，可自适应克服时变码间干扰的同时，避免信道估计误差对通信性能的影响，提高通信速率。理论、仿真和试验均证明矢量均衡系统比标量均衡系统具有更好的均衡效果，利用声压与水平振速的线性组合信号与垂直振速信号的非相干特性进行自适应多通道均衡的均衡性能最佳。利用时反的空-时聚焦特性对信道多途进行有效地抑制，可有效地降低均衡器的误码率。利用水声信道关于时间非对称的特性进行双向判决反馈均衡，进一步降低均衡误码率。进行了垂直矢量阵自适应多通道信道均衡器的结构设计，理论、仿真和试验分析了垂直矢量阵自适应多通道信道均衡器的性能，为时变信道中抑制噪声干扰，提高通信质量的能力提供了新的思路。.本课题为解决实际时变水声环境下兼顾远距离、高速率、高可靠的水声通信提供了新思路和理论依据，试验验证了所提出方法的有效性和可行性。为增强通信系统对水下环境的适应能力，发展稳健水声通信系统奠定基础。.本课题成果被应用于军民融合海洋开发、海洋环境实时监测、水下网络信息收集等领域，有效解决了水下通信环境适应性差的瓶颈，改善了舰船之间在复杂水声环境中的互通信息的能力，带来很好的经济效益和社会效益。.本课题研究期间，共发表论文9篇，其中三大检索5篇；取得专利6项，其中已授权1项，公开5项；取得软件著作权2项；科研奖励1项：“环境认知多模水声通信技术”于2018年获黑龙江省科技进步一等奖。