空时分组码通信中的一类ICA盲检测方案

ICA based blind detection scheme in space-time block coding communications

空时分组码(STBC)通过使用发射分集策略和空时编码方案可以明显改善系统性能。然而,其接收端必须获得准确的信道状态信息(CSI)才能进行有效的信号检测。而对于复杂的无线通信环境,这种前提条件有时却难以得到满足。独立分量分析(ICA)是一种将一个复杂的数据集合分解为多个独立子集的盲源分离(BSS)技术。通常情况下,即使没有空间信道的任何信息,ICA也可以仅凭接收信号恢复出发射信号。提出了一种利用ICA技术的STBC盲信号检测方案,在建立了适用于ICA的特定通信系统模型后,几种典型的ICA算法被用来进行性能比较。理论分析表明,ICA盲接收技术的应用可以在一定程度上替代基于信道估计的传统方法,增强系统对信道估计错误的顽健性。仿真实验结合了具体的STBC系统,比较了基于ICA的不同方案的性能,并讨论了最优的信号检测方案。

Space-time block coding （STBC） schemes are capable of improving system performance by using transmit diversity strategy and specific coding schemes. Nevertheless, they need precise channel state information （CSI） at the receiver end in order to achieve good detection performance, which is difficult to be guaranteed in some specific scenarios because of complicated communication conditions. Independent component analysis （ICA） technique is to separate a complex data set into a couple of independent sub-sets, which belongs to the family of blind source separation （BSS） technique. ICA techniques were exploited into the STBC communication systems, and they were used to detect the transmitted signals blindly, which need not the channel estimation. After analyzing the essential structure of STBC system, the specific model suitable to ICA is established, and several typical ICA algorithms are adopted to make a comparison. The robustness against channel estimation errors can be acquired by using the ICA based schemes. Simulation results demonstrate the validity of proposed approaches, and after the comparison among different ICA based detection schemes, the optimal one is found and the discussions are also given.