基于发射机预处理的中继协助下行直接序列CDMA性能评估  

Performance evaluation of relay-aided downlink direct sequence CDMA based on transmitter preprocessing

作　　者：张淑萍[1] 赵桂钦[2] 

机构地区：[1]内蒙古商贸职业学院,呼和浩特010070 [2]上海交通大学,上海200231

出　　处：《激光杂志》2014年第11期75-80,共6页Laser Journal

基　　金：国家自然科学基金资助项目(61102007);内蒙古自然科学基金(2013MS0926)

摘　　要：针对多用户下行链路直接序列码分多址系统中DL信号可能会相互影响导致中继处产生多用户干扰的问题,本文提出了一种基于矢量量化信道脉动响应的多用户发射预处理系统。该系统在各个中继处通过基于训练序列的估计技术对CIR进行估计并随机矢量量化这些被估计的CIR,同时其幅值及相位通过噪声衰退反馈信道被反馈至基站。基站内利用通过线性检测器恢复的CIR进行预处理矩阵的公式化以减少中继处DL多用户的干扰。分析结果表明,当调用受噪声及衰退影响的VQ-CIR实现预处理矩阵时,可以使得误码率性能降低,而基于VQ-CIR的MUTP的BER性能与基于完全CIR假定所得的性能相近。In a multi-user downlink direct sequence code division multiple access system,the DL signals may interfere with each other resulting in MUI at the relays,to solve this problem,this paper proposes a system with multi-user transmitter preprocessing based on vector quantized channel impulse responses.The CIRs are estimated with the aid of training-sequence based estimation technique at each of the relays.These estimated CIRs are then VQ and the magnitudes and phases are fed back to the base station through feedback channels,that conflict noise and fading.At the BS,the CIRs recovered using a linear detector are then exploited to formulate the preprocessing matrix to mitigate the DL multi-user interference at the relays.Our study shows that the attainable bit-error-rate degrades when noise and fading contaminated VQ-CIRs are invoked to realize the preprocessing matrix.Nevertheless,the resultant BER performance of the MUTP based on VQ-CIRs acquired via ideal feedback remains close to that achieved with perfect CIRs assumption.

关 键 词：发射机预处理 中继协助 下行链路 直接序列码分多址 矢量量化 

分 类 号：TN915[电子电信—通信与信息系统]