一种基于维纳滤波器抗MAI的新方法

A New Anti-MAI Method based on Wiener Filter

文中研究了DS-CDMA移动通信系统中一种基于维纳滤波器的抗多址干扰MAI(Multiple Access Interfere)的新方法——辅助矢量滤波器AVF(Auxiliary Vector Filter),该滤波器基于维纳滤波器,重新构造出接收信号,引入辅助矢量的概念,使辅助矢量完全正交于干扰矢量,这样就能达到完全消除系统中多址干扰的目的,同时推导出了辅助矢量和权系数的求解公式。该方法具有无需求逆矩阵,可运用于下行链路,便于盲实现,计算复杂度低等优点。仿真结果表明:在DS-CDMA移动通信系统中,信道噪声为加性高斯白噪声信道(AWGN),不同的干扰强度和不同的干扰用户数两种环境下,辅助矢量滤波器有着较低的误码率,能够有效地去除DS-CDMA系统中的多址干扰,性能要优于传统相关滤波器以及多用户检测技术中的解相关算法和最小均方误差算法(MMSE)。

In DS-CDMA system,a new anti-MAI method based on Wiener filter,the Auxiliary Vector Filter,is studied.The filter,based on Wiener filter,reconstructs the received signal,introduces the concept of the auxiliary vector that is orthonormal to the interference vector,so that it could cancel the MAI completely.In addition,the expressions of the auxiliary vector and the weight coefficient are also given.The method needs no more module,and no inversion of matrix.Also it could be blindly applied to the forward（base-to-mobile） and is with very low complexity.The simulation results indicate that in DS-CDMA system,the channel is AWGN,and in the two environments of different interference strehghs and different number of the interference users,the auxiliary vector filter is very low in bit error rate,and could effectively cancell the MAI,and its performance is much better than the MF,and the decorrelating filter and MMSE of the Multi-User Detection（MUD）.