【作者】 徐磊；

【导师】 卢建军； 曾召华；

【作者基本信息】 西安科技大学 ， 通信与信息系统， 2004， 硕士

【摘要】 在CDMA（码分多址）通信系统中，同信道干扰（CCI）和码间干扰（ISI）是限制通信性能的两个主要因素。虽然，ISI可以在时域通过均衡加以补偿；CCI可以在空域利用多用户检测的方法加以抑制。但是，在无线通信系统中，CCI和ISI常常同时存在，只使用时域一维处理或空域一维处理不能有效的同时抑制CCI和ISI，因此需要使用空时处理技术。本论文通过对分集接收技术及RAKE接收技术的分析，提出了一种盲自适应空时2D-RAKE接收算法----空时解重扩恒模算法（ST-DRCMA）。该算法在现有的恒模算法（CMA）的基础上，进行了一定的改进，充分利用了CDMA系统中扩频波形信息和信号的恒模特性。计算机仿真结果表明此算法可以有效的改善系统的接收性能。同时本论文分析了多用户检测的原理、方法以及空时优化准则。利用空时优化准则，结合多用户检测提出了两种空时多用户检测器的结构方案：一种是空时MMSE解相关多用户检测器，另一种是空时MLSE判决反馈多用户检测器。计算机仿真结果表明这两种方案继承了解相关多用户检测器和判决反馈多用户检测器在抗远近效应方面的能力，并进一步改善了CDMA通信系统的性能。更多还原

【Abstract】 ABSTRACTCo-channel interference (CCI) and Inter-symbol interference (ISI) are two major factors limiting performance of CDMA communication system. Although ISI can be compensated in time-domain and CCI can be restrained in space-domain, these two interferences cannot be eliminated simultaneously by only using time-domain or space-domain processing technique because of their simultaneous existence in the wireless communication system. So it is necessary to study Space-Time processing technique.This dissertation proposes a blind adaptation space-time 2D-RAKE receiving algorithm----ST-DRCMA (Space-Time De-Re-spread Constant Modulus algorithm) by studying techniques of scattering-concentrate receiving and RAKE receiver. This algorithm, an improved method based on CMA (Constant Modulus algorithm), utilizes the information of spread codes and the performance of constant modulus in CDMA communication system. The results of the computer simulation can prove that this algorithm can improve the capacity of the receiver.Analyzing the theories and methods of Multiuser Detection (MD) and space-time optimizing principles, this dissertation proposes two schemes of Space-Time MD combining the space-time processing and Multiuser Detection. One is the Space-Time MMSE Decorrelating MD, and another is Space-Time MLSE Decision-Feedback MD. The results of the computer simulation also prove that these two schemes not only inherit the ability to resist “the near far problem” in Decorrelating MD and Decision-Feedback MD, but also improve the performance of communication system.更多还原