基于子空间的MMSE群盲多用户检测算法

针对CDMA上行链路系统中,基站已知小区内用户的扩频码而对小区外用户扩频码未知的情况,提出一种基于子空间方法的最小均方误差(minimum mean square error,MMSE)群盲多用户检测算法。该算法利用所有已知的扩频码有效消除了多址干扰,采用改进的紧缩近似投影子空间(projection approximation subspacetracking with deflation,PASTd)跟踪算法实现信号子空间的自适应跟踪,提高了收敛速度。仿真结果表明,所提算法收敛速度快,输出信干噪比和误码率性能优于PASTd盲多用户检测,逼近奇异值分解(singular value decom-position,SVD)群盲多用户检测,并保持了较低的计算复杂度。

Subspace-based MMSE group-blind multiuser detection algorithm

A subspace-based minimum mean square error(MMSE) group-blind multi-user detection algorithm for CDMA uplink is proposed where the codes of intra-cell users are known but the codes of inter-cell users are unknown.The interferers are suppressed by exploiting the spreading sequences of all known users.An improved projecting approximation subspace tracking with deflation(PASTd) algorithm is proposed for estimating the signal subspace adaptively which enhances the convergence rate of the algorithm.Simulation results show that the proposed algorithm has a faster convergence rate and much less computational complexity,and the output bit error rate(BER) and signal-to-interference-plus-noise-ratio(SINR) performance are superier to the PASTd blind multiuser detection algorithm and close in on the singular value decomposition(SVD) group-blind multiuser detection algorithm.