CDMA系统中基于ICA的多用户检测方法.doc

学校代码： 学 号： Hefei University 毕业论文（设计） BACHELOR DISSERTATION 论文题目： CDMA系统中基于ICA的多用户检测方法 学位类别： 工学学士 年级专业： 08通信工程 班 作者姓名： 导师姓名： 完成时间： 2012.05.20 CDMA系统中基于ICA的多用户检测方法 中 文 摘 要 本文比较全面的从第二章到第四章分别介绍了CDMA扩频通信的原理和现有的各种多用户检测技术以及独立分量分析(ICA: Independent Component Analysis)这种盲源分离算法，并在此基础上，从多用户信号的统计独立同分布的统计特征出发，分析研究了CDMA通信中多用户信号的数学模型，将盲源分离技术应用到多用户信号检测当中来。 传统的信道估计算法需要训练序列使接收端的参数调整到理想状态，而本文提出的基于ICA的信道估计的多用户检测算法不需要训练序列，它是利用下行信道的固有特点。基于ICA后处理的匹配滤波多用户检测是用传统的检测器的输出来初始化ICA的迭代，它不但充分利用多用户信号的已知信息，克服了ICA的不确定性问题，同时也充分利用了多用户信号的统计独立性，仿真实验结果证明这种多用户检测算法在高信噪的情况下，误码性能改善随着信噪比的提高不断增加。 关键词：码分多址；独立分量分析；匹配滤波；盲多用户检 A Multiuser Detection Method Based on ICA in CDMA System ABSTRACT In this paper, the principle of spread sequence communication and all kind of the current multi-user detection techniques and the independent component analysis (ICA) algorithm are respectively analyzed completely in chapter Ⅱ、chapter Ⅲ and chapter Ⅳ. Based on the statistical feature of multi-user signal that the signal of every user’s and every channel is statistical independent with each other and take the same distribution, the mathematical model of the received multi-user signal is fully researched, then the blind signal detection algorithm is introduced into the multi-user signal detection. Traditional delay estimation based on ICA requires the trail sequences to initialize the receiver, but the new algorithm based on ICA does not need the trail sequences. It is based on the channel character of downlink.Based on ICA post processing matched filter multi-user detection lets the output of traditional matched filter to initialize the ICA iterations, not only the known spread information of interesting user is used to overcome the uncertainness of ICA, but also the character of statistical independenc