一种码分多址水声多用户接收系统-声学技术.pdfVIP

第 29 卷第 1 期 声 学 技 术 Vol.29, No.1 2010 年 2 月 Technical Acoustics Feb., 2010 一种码分多址水声多用户接收系统 魏丽萍，陈 岩，陈 庚，郭中源，贾 宁 ( 中国科学院声学研究所，北京 100190) 摘要：研究了一种水声异步多用户通信非集中式接收机系统，将码分多址和空时自适应滤波、多通道判决反馈均衡 相结合，克服多用户系统中的多址干扰(MAI) 以及水声信道多途效应引起的码间干扰(ISI)，实现指定用户的正确接收。 利用实测多通道浅海水声信道响应函数进行了三个用户的异步通信仿真，分别比较了空时滤波均衡与单通道直接解 扩、空间分集合并均衡等接收算法的性能，显示了空时滤波均衡接收机在抑制多址干扰、码间干扰、正确区分不同 用户等方面的优点。码分多址机制和空时滤波均衡结合使用的特点使系统适合于低速数据传输且水声信道变化较慢 的场合。 关键词：码分多址；非集中式；多用户接收；空时自适应滤波；判决反馈均衡 中图分类号：TN911.5 文献标识码：A 文章编号：1000-3630(2010)-01-0009-05 DOI 编码：10.3969/j.issn1000-3630.2010.01.002 An underwater acoustic multi-user communication receiver based on CDMA and space-time filtering and equalization WEI Li-ping, CHEN Yan, CHEN Geng, GUO Zhong-yuan, JIA Ning (Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China) Abstract: An underwater asynchronous multi-user communication decentralized receiver is studied. The receiver uses some techniques such as CDMA, space-time adaptive filtering and multi-channel decision-feedback equalization to overcome multi-access interference (MAI) existing in multi-user system and inter-symbol interference (ISI) caused by multi-path effect of underwater acoustic signals. The objective is to receive desired user signal correctly. The simulations of asynchronous underwater acoustic communication between three users are carried out by real shallow water multi-channel impulse response functions. The performance of space-time filtering and equalization receiver is compared respectively to single-channel direct de-spreading receiver and space diversit