非Gaussian信道DS-CDMA系统中的多用户检测算法

Multiuser detection algorithm for DS- CDMA systems with non-Gaussian noise

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。

An adaptive multiuser detection algorithm 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 multiuser detectors based on the classical white Gaussian assumption. This receiver simultaneously combats multiple-access interference (MAI) and non-Gaussian impulsive noise. The channel parameters are estimated and the transmitted signals are detected simultaneously by a simple recursive algorithm derived from the EM/SAGE algorithm. Analytical and simulation results show that the technique is robust with wider applicability than conventional multiuser detectors in terms of near-far resistance and bit error rate (BER) when either MAI or non-Gaussian impulsive noise is dominant.