时频双选信道OFDM系统的低复杂度MMSE-SD算法  

Low-complexity MMSE-SD Algorithm for OFDM Systems over Doubly-selective Channels

作　　者：惠永涛[1] 李兵兵[1] 同钊[1] 薛磊磊[1] 

机构地区：[1]西安电子科技大学综合业务网理论及关键技术国家重点实验室西安710071

出　　处：《电子与信息学报》2013年第2期261-266,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(61271299);高等学校学科创新引智计划(B08038)资助课题

摘　　要：在时频双选信道OFDM系统中,针对最小均方误差连续检测(MMSE-SD)算法求逆运算导致计算复杂度过高的问题,该文提出一种改进的低复杂度MMSE-SD算法。该算法首先对信道矩阵和检测矩阵进行扩展处理,然后建立扩展矩阵和原矩阵之间的关系,每次检测用扩展矩阵的迭代求逆代替原矩阵的直接求逆。理论分析和仿真结果表明:和原MMSE-SD算法相比,该改进算法在保持原算法性能的基础上,大幅度降低其计算复杂度;与其它算法相比,该改进算法兼顾了系统性能与计算复杂度,当归一化多普勒频移增大时,其计算复杂度保持不变而性能更优。Because of the problem of the Minimum Mean Square Error with Successive Detection （MMSE-SD） algorithm with high computational complexity for OFDM systems in the presence of frequency and time double selective channels, an improved low-complexity MMSE-SD algorithm is proposed in this paper. The algorithm extends firstly the channel matrix and detection matrix, then establishes the relationship between them by using recursive inversion instead of direct inversion at each detection. Both theoretical analysis and simulation results show that the improved algorithm retains the performance of the original algorithm with much lower computational complexity compared to the original MMSE-SD algorithm; Compared to other algorithms, the improved algorithm balances the performance with the computational complexity. The larger normalization Doppler frequency shift, the better performance it possesses with the unchanged computational complexity.

关 键 词：无线通信 双选信道 正交频分复用 载波间干扰 最小均方误差连续检测 Greville递归求逆 

分 类 号：TN92[电子电信—通信与信息系统]