异步DS-CDMA系统中的最优时空线性多用户检测器

OPTIMAL LINEAR SPACE-TIME MULTIUSER DETECTOR FOR ASYNCHRONOUS DS-CDMA SYSTEMS

该文给出了一种适用于异步DS-CDMA系统的通用线性时空二维多用户检测方法,它将所有线性多用户检测器归结到一个统一的数学模型之下。基于此模型,该文将时空线性多用户检测问题转化为一个权矢量的优化问题,并在线性约束最小方差(LCMV)准则下给出了权矢量的优化解。对现有的几种典型线性多用户检测器的分析表明,这些方法都可以看作是该文提出的通用时空线性多用户检测方法的特例,且只能在某种限定条件下得到局部最优解,因此其抑制多址干扰和噪声的能力都低于文中的最优时空线性多用户检测器。最后,给出了数值仿真结果。

A versatile signal model suitable for linear space-time multiuser detectors in asynchronous DS-CDMA systems is proposed. Based on the model, a versatile linear space-time multiuser detector is presented and its optimal solution according to the Linear Constrained Minimum Variance (LCMV) criterion is deduced. The analyses of the existent linear multiuser detectors demonstrate that, these methods are just the special cases of the versatile detector in this paper and can only achieve the suboptimal solution. Hence their interference camceling performance is inferior to the optimal detector in this paper. Finally, numerical simulations are presented.