基于变抽头长度的水声通信多用户检测技术研究

发布时间：2018-03-04 06:13

本文选题：水声通信　切入点：协作通信　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,随着海洋经济的不断发展,以及军事和商业应用上的需求,水声通信得到了商业界和学术界的广泛关注。然而水声信道的复杂多径传播、大传播延迟、有限可用带宽等特点对多用户水声通信的链路可靠性带来了巨大的挑战。为改善链路可靠性,本文将协作通信技术应用于多用户水声通信,并在此基础上针对水声信道的特点展开研究,论文的主要研究内容如下:首先,建立了非协作模式下的多用户水声通信系统模型,对水声信道特性进行了分析,并采用BELLHOP模型建立了水声信道,在IDMA迭代多用户检测算法的基础上,研究了基于固定抽头长度的多用户检测。其次,针对抽头长度会很大程度上影响多用户检测性能,以及计算复杂度的问题,提出了非协作模式下基于变抽头长度的多用户检测方案,该方法使用抽头长度更新算法根据水声信道环境不同自适应调整抽头长度到最优,从而提高系统性能。为进一步提高链路可靠性,引入协作通信技术,建立了多用户水声协作通信系统模型,综合考虑合并方式和抽头长度对检测性能的影响,提出了联合自适应合并和变抽头长度(JACVT)的多用户检测方案。通过仿真分析验证了变抽头长度多用户检测方案的可行性和有效性。最后,考虑频谱资源利用率问题,引入同时同频全双工技术,建立了基于自干扰消除的非协作多用户水声通信系统模型。针对该系统中自干扰现象严重问题,分析步长因子和滤波器阶数对自干扰消除性能的影响,综合考虑了自干扰、多址干扰和码间干扰的消除,提出了基于变步长变阶数自干扰消除的变抽头长度(SIC-VT)多用户检测方案。同时在全双工协作模式下,提出了基于自干扰消除的联合自适应合并和变抽头长度(SIC-JACVT)多用户检测方案,进一步提升系统性能。通过仿真分析了自干扰消除的影响因素,证明了变步长变阶数多用户检测方案的性能优势。
[Abstract]:In recent years, with the continuous development of marine economy and the demand of military and commercial applications, underwater acoustic communication has received extensive attention in the commercial and academic circles. However, the complex multipath propagation of underwater acoustic channels leads to large propagation delays. The limited available bandwidth brings a great challenge to the link reliability of multi-user underwater acoustic communication. In order to improve the link reliability, this paper applies cooperative communication technology to multi-user underwater acoustic communication. On this basis, the characteristics of underwater acoustic channel are studied. The main contents of this paper are as follows: firstly, the multi-user underwater acoustic communication system model under non-cooperative mode is established, and the characteristics of underwater acoustic channel are analyzed. Based on the IDMA iterative multi-user detection algorithm, the multi-user detection based on fixed tap length is studied. Secondly, the tap length will greatly affect the performance of multi-user detection. As well as the computational complexity, a multi-user detection scheme based on variable tap length in non-cooperative mode is proposed. The tap length updating algorithm is used to adaptively adjust the tap length to the optimum according to the different underwater acoustic channel environment. In order to further improve the link reliability, a multi-user underwater acoustic cooperative communication system model is established by introducing the cooperative communication technology. The influence of combination mode and tap length on the detection performance is considered synthetically. A multiuser detection scheme based on combined adaptive merging and variable tap length (JACVT) is proposed. The feasibility and effectiveness of the multi-user detection scheme with variable tap length are verified by simulation analysis. Finally, the problem of spectrum resource utilization is considered. The simultaneous frequency full-duplex technique is introduced to establish a non-cooperative multi-user underwater acoustic communication system model based on self-interference cancellation. The effects of step size factor and filter order on the performance of self-interference cancellation are analyzed, and the elimination of self-interference, multi-access interference and inter-symbol interference are considered synthetically. A multiuser detection scheme for SIC-VT based on variable step size and variable order self-interference cancellation is proposed. At the same time, a joint adaptive merging and variable tap length SIC-JACVT multiuser detection scheme based on self-interference cancellation is proposed in full duplex cooperation mode. The influence factors of self-interference cancellation are analyzed by simulation, and the performance advantages of multi-user detection scheme with variable step size and variable order are proved.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.3

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