MIMO OFDM系统中一种基于MMSE准则的优化型Turbo-BLAST检测算法

摘要

In this paper,an optimized Turbo-BLAST detection algorithm employing the BLAST scheme for MIMO OFDM systems is proposed,which adopt the soft-output MMSE-PIC detector.With taking into account the channel estimation error and channel spatial correlation,the weight of the MMSE filter is optimized,so that the decreased accuracy performance of extracting soft information is improved for existing the channel estimation error and channel spatial correlation in practice.Furthermore,the closed-form solution of the optimal weight and the extrinsic information expression of the iterative loop are concluded.Finally,simulations also show that the algorithm outperform the traditional MMSE-PIC iterative detection algorithm in the performance of the BER by the different conditions of channel estimation error and channel spatial correlation.At the same time,the computational complexity of the designed algorithm increased less.%本文提出了一种MIMO OFDM系统中使用BLAST空时码的优化型Turbo迭代检测算法.该算法采用基于软输出的MMSE-PIC检测器,并在联合考虑信道估计误差与信道空间相关性的基础上,最优化该MMSE滤波器的权系数,从而改善了由于实际中存在信道估计误差和信道空间相关性所导致的软信息提取精度恶化现象.此外,文中进一步推导获取了该最优化权系数的闭式解和迭代循环的外信息表达式.最后,仿真结果也表明在不同的信道估计误差和信道空间相关性条件下,该算法的BER性能总优于传统型软输出的MMSE-PIC迭代检测算法,且计算复杂度相对增加较小.