基于子空间跟踪的线性共轭半盲多用户检测

考虑实际的MC-CDMA上行链路系统,在深入研究基于子空间的MMSE半盲多用户检测算法的基础上,针对原算法引入子空间误差导致检测性能下降的问题,提出MC-CDMA系统下一种基于子空间跟踪的线性共轭MMSE半盲多用户检测算法.将子空间方法和线性共轭的思想相结合,应用新定义的信号子空间设计了基于子空间方法的线性共轭MMSE检测器,采用OPAST子空间算法实现了信号子空间的自适应跟踪.仿真结果表明,与以往的基于子空间的MMSE半盲多用户检测相比,此算法有效地提高了信干噪比,降低了系统的误比特率.

Linear Conjugate Semi-blind Multiuser Detection Based on Subspace Tracking

With the subspace-based minimum-mean-square-error(MMSE) semi-blind multiuser detection investigated in-depth,a linear conjugate MMSE semi-blind multiuser detector based on subspace tracking algorithm is proposed against the performance degradation induced by signal subspace estimation errors in the conventional algorithm for multicarrier CDMA(MC-CDMA) uplink.Combining the subspace method with the idea of linear conjugate,a linear conjugate MMSE detector is designed on the basis of subspace method by a newly defined signal subspace.Moreover,the orthogonal projection approximation subspace tracking(OPAST) algorithm is used for adaptive subspace estimation.Simulation results showed that the proposed algorithm can improve the signal-to-interference-plus-noise-ratio(SINR) output and reduce the bit-error-rate(BER) performance effectively,compared with previous MMSE semi-blind multiuser detection algorithms.