一种新的基于LMS的自适应半盲多用户检测算法  

Novel adaptive semi-blind multiuser detection algorithm based on LMS

作　　者：孟艳[1] 汪晋宽[1] 朱俊[1] 宋昕[1] 

机构地区：[1]东北大学信息科学与工程学院,辽宁沈阳110004

出　　处：《系统工程与电子技术》2008年第8期1570-1573,共4页Systems Engineering and Electronics

基　　金：博士学科点专项科研基金(20050145019)资助课题

摘　　要：深入研究了最小均方(least mean square,LMS)盲多用户检测,提出多载波码分多址(multicarrierCDMA,MC-CDMA)系统下一种基于子空间约束LMS的自适应半盲多用户检测算法。该算法设计了一种最小输出能量(minimum output energy,MOE)半盲检测器,给出一种子空间约束LMS算法自适应得到MOE检测器的权向量。为了降低计算复杂度,采用修正的紧缩近似投影子空间跟踪(projection approximation subspace track-ing with deflation,PASTd)算法自适应跟踪信号子空间。通过利用小区内所有用户的扩频码有效地抑制了多址干扰,将权向量约束在信号子空间,降低了噪声子空间的影响,从而提高了收敛速度,改善了输出信号干噪比和误码率性能。仿真实验验证了该算法的有效性。From the foundation of the investigation on the least mean square （LMS） blind multiuser detec- tion, an adaptive semi-blind multiuser detection algorithm based on the subspace constrained LMS is proposed for multicarrier CDMA （MC-CDMA） uplink. A semi-blind multiuser detector based on the minimum output en- ergy （MOE） principle is designed, and a subspace constrained LMS algorithm is proposed to obtain the MOE weight vector adaptively. To reduce the computational complexity, an improved projection approximation sub- space tracking with deflation （PASTd） algorithm is adopted for adaptive signal subspace estimation. This pro- posed algorithm suppresses the interferers by exploiting the spreading sequences of all known users and miti- gates the noise by constraining the weight vector in the signal subspace. As a result, the performance of the out- put slgnal-to-interference-plus-noise-ratio （SINR） and the bit error rate （BER） is improved. Simulation results demonstrate the effectiveness of the proposed algorithm.

关 键 词：多载波CDMA 半盲多用户检测 最小输出能量 最小均方算法 

分 类 号：TN911.7[电子电信—通信与信息系统]