Multiuser detection for DS-CDMA systems in non-Gaussian channels

An adaptive multi-user detector was developed for direct-sequence code division multiple access(DS-CDMA)systems corrupted by non-Gaussian channel noise,which can be quite detrimental to the performance of the multi-user detectors based on classical white Gaussian assumption.This receiver simultaneously combats multiple-access interference(MAI)and non-Gaussian impulsive noise.The channel parameters are estimated and transmitted signals are jointly detected by a simple recursive algorithm derived from the EM/SAGE algorithm.Analytical and simulation results show that the proposed technique is robust with wider applicability than conventional multi-user detectors in terms of near-far resistance and bit-error ratio(BER)when either MAI or non-Gaussian impulsive noise is dominant.

非Gaussian信道DS-CDMA系统中的多用户检测算法

对于实际非Gaussian加性噪声信道条件下的DS-CDMA系统,基于理想Gaussian白噪声假设的多用户接收机的性能会严重下降。为了同时抑制多址干扰和非Gaussian脉冲噪声的影响,提出了一种自适应多用户接收机,其模型参数的估计和传输数据的检测采用EM/SAGE递归结构联合进行。该接收机具有实现简单、鲁棒性高、适用性强的优点。分析和仿真结果表明,无论是在多址干扰还是在非Gaussian脉冲噪声占主导的情况下,EM/SAGE-MUD算法在降低误码率,克服远近效应方面比起传统的多用户检测方法有显著改善。