空时分组编码多用户系统下ZF解码器设计  

Design of ZF decoder of space-time block coded for multiuser system

作　　者：张碧军[1] 朱光喜[1] 刘文明[1] 

机构地区：[1]华中科技大学电子与信息工程系,湖北武汉430074

出　　处：《华中科技大学学报（自然科学版）》2006年第1期64-67,共4页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家高技术研究发展计划资助项目(2003AA12331005);国家自然科学基金重大研究计划资助项目(60496315)

摘　　要：提出了一种适用于时变信道下的空时分组编码多用户系统的解码器设计方案.空时分组编码多用户系统下,传统迫零(ZF)解码器设计假定信道准静态衰落.信道时变时,该ZF解码器在解码某用户信号时引入符号间干扰(ISI),且这种干扰随信道时变增大而增加.新解码器基于ZF思想设计,在接收端构造一变换矩阵,作用该矩阵于时变信道矩阵,使之对角化而达到消除ISI影响的目的.理论仿真结果表明,对于各种信道衰落速率,在高信噪比下,传统ZF解码器均出现误码率平层,且信道时变越大,平层越严重,而新解码器不存在平层现象,获得同准静态衰落信道下几乎一致的分集增益,仅有部分编码增益损失;对于信道准静态衰落,两种解码器获得了一样的性能.A scheme of a space-time block coded for multiuser system in time-selective fading channels was proposed. In this system, the design of conventional zero forcing （ZF） decoder was made on the basis of the assumption that channels were quasi-static fading. When the channels were time-selective fading, the decoder was induced to the inter-symbol interference （ISI） to obtain one user＇s signals, and the ISI became larger resulting from the increase of the channels time variations. The new decoder was designed on the basis of ZF idea. At the receiver, a transformed matrix was constructed and the time variable channel matrix was multiplied. It was a diagonal matrix to remove ISI completely. The theoretical simulation result showed that the conventional ZF decoder exhibited error floors with various fading rates of channels at high signal-to-noise ratio values. The error floors became severe as the increase of fading rate. The new decoder did not exhibit error floors and it obtained almost the same diversity gains as the quasi-static fading channel. The partial loss of coding gain was induced. As to the quasi-static fading of the channels, both decoders obtained the same oerformance.

关 键 词：解码器 多用户 空时分组编码 时变信道 

分 类 号：TN911[电子电信—通信与信息系统]