平坦瑞利衰落信道中多用户检测器的性能分析

在采用传统信号检测方式的CDMA系统中,多址干扰限制了系统的容量和性能.本文分析了在精确估计信道的情况下平坦瑞利衰落信道中的判决反馈和线性解相关两种多用户检测器的性能,主要分析了二者的误码率性能和抗远近效应的能力,并首次分析了衰落信道中的渐近多用户效率(AME).结果表明,判决反馈多用户检测器的渐近多用户效率优于线性解相关检测器.

Performance of Multiuser Detector for CDMA System in Flat Rayleigh Fading Channel

In the CDMA system using the conventional signal detection, the system capacity is limited by the multi-access interference (MAI). Multiuser detection, which makes use of cross-correlation information between two spread spectrum codes, can reduce or eliminate MAI so as to mitigate the near-far effects and increase the system capacity. In this paper we compare performance of linear decorrelator multiuser detector and decision-feedback (DF) detector for the fla Rayleigh fading synchronous channel. Assuming perfect channel estimation, we show that the DF has much lower BER and better antinearfar effect than the decorrelator and Prove that the ideal DF has unity Asymptotic Multiuser Efficiency.