基于预编码的混合迭代均衡算法  

Hybrid iterative equalization algorithm based on precoding matrix

作　　者：李一兵[1] 刘海涛[1] 叶方[1] 林云[1] 

机构地区：[1]哈尔滨工程大学信息与通信工程学院,黑龙江哈尔滨150001

出　　处：《哈尔滨工程大学学报》2016年第3期455-460,共6页Journal of Harbin Engineering University

基　　金：国家自然科学基金资助项目(61301095;51374099);黑龙江省自然科学基金资助项目(F201345);黑龙江省青年科学基金资助项目(QC2012C070)

摘　　要：针对LTE下行多输入多输出正交频分多址(MIMO-OFDM)系统中的天线间干扰和多径干扰问题,提出一种低复杂度的迭代均衡算法。该算法在接收端通过预编码矩阵将发射信号扩展到所有子载波上,从而减少部分子载波深衰落对扩展前原始发射信号的影响。算法在接收端引入最小均方差误差排序QR分解(MMSE-SQRD)软干扰消除均衡算法,一方面避免传统基于最小均方误差(MMSE)并行软干扰消除均衡算法中矩阵求逆运算,进而降低了算法复杂度,另一方面利用信道排列,优先检测信噪比最大的传输符号进而提高检测准确性。同时通过预编码对重构信号进行预处理,进而缓解在迭代干扰消除过程中的误差传播。仿真结果表明:在4发4收场景下,误码率为10-5时,所提算法信噪比改善约0.7 d B。To address co-antenna and multipath interferences in the LTE downlink multi-input multi-output orthogonal frequency division multiplexing communication system,we propose a low-complexity hybrid iterative equalization algorithm. In a receiving terminal,the proposed algorithm utilizes a precoding matrix to spread symbols over all subcarriers,which relieves the influence of deep fading in some parts of the subcarriers. In a receiver,the soft interference elimination algorithm is adopted based on the minimum mean-square-error（ MMSE）-sorted QR decomposition to avoid complexity when solving an inverse matrix. This matrix is always involved in traditional parallel soft interference elimination equilibrium algorithms based on minimum mean square error（ MMSE） equalization. In addition,using a channel arrangement,the soft interference elimination algorithm prioritizes the detection of transmission symbols with a maximum noise-to-signal ratio（ SNR） to improve detection accuracy. Furthermore,the reconstructed signals is preprocessed by a precoding matrix,which decreases error propagation in iteration processing.Simulation results show that the performance of the proposed algorithm is better than that of existing iterative interference cancelation algorithms. Specifically,when the system is equipped with four transmitters and four receivers,the bit error rate is 10-5and the SNR is improved by approximately 0.7 d B.

关 键 词：多输入多输出正交频分多址 最小均方误差排序QR分解 预编码矩阵 最小均方误差 TURBO均衡 

分 类 号：TN292[电子电信—物理电子学]