在CDMA通信系统中，由于多个用户的随机接入，所使用的扩频码集一般并非严格正交，码片之间的非零互相关系数将引起各用户间的干扰，即为多址干扰。多址干扰的存在不仅会严重限制系统的容量，而且强的多址信号还会淹没弱的用户信号。为了能够有效的抑制CDMA移动通信系统中的多址干扰，多用户检测的研究成为现在通信领域的研究热点。 本文首先对理论上及性能上接近最佳多用户检测的次最佳多用户检测进行理论研究，计算并分析了解相关检测器、最小均方误差检测器（MMSE）、最佳线性检测器的性能指标（输出能量、信噪比、渐近有效性、误码率以及收敛特性等）。 其次，对解相关检测器、最小均方误差检测器（MMSE）的各项性能指标进行了仿真验证，并对单用户检测器、传统检测器、解相关检测器、最小均方误差检测器进行了比较说明。仿真结果表明解相关检测器和最小均方误差检测器具有优良的收敛性能，并且信噪比和误码率也达到了较为理想的效果。 最后，在对线性多用户检测器深入研究的基础上，对基于信号子空间的盲多用户检测算法进行了理论研究和仿真。从理论上对这种算法进行分析的同时，进行了相关的仿真验证，结果证明了SINR和BER取得的良好效果。

In CDMA mobile communication system, because of the multi-user’s access, the spread spectrum code they used are normally not quadrature rigidly. The nonzero cross correlation coefficient between codes will arouse the interference between the users, which is called multiple access interference (MAI). The existence of the MAI will not only restrict the capacity of the system but also submerged the poor signal. So MUD is becoming into the hotspot in the communication research. Firstly, the multi-user detector that relatively integrity in theory and proximal to optimal multi-user detector is discussed and Decor elating Detector(DEC), Minimum Mean Square Error Detector(MMSE), Optimal linear Detector together with the multi-capability indexes (output energy, SNR, bit error rate, asymptotic efficiency, convergence etc.) are studied and analyzed in this thesis. Secondly, simulated and compared all kinds of capability indexes within the single user detector, traditional detector, DEC and MMSE detectors. The results indicated the DEC and MMAE detectors have a better convergence capability. At the same time, the SNR and the BER achieved a perfect effect. Lastly, on the base of deep research of linearity multi-user detector, analyze and plentiful simulate the blind multi-user detectors based on the signal subspace in MATLAB. Along with the analyzer in the theory, did some kinds of simulations. The result indicated that this arithmetic has a good result about SNR and BER. At the same time, put out some views on the future.