基于MIMO系统的盲均衡算法研究

Research on Blind Equalization Algorithm in MIMO Systems

MIMO通信系统中,随着数据率的不断提高,信道呈现出频率选择性,尤其是多径干扰和多用户干扰将会使接收端产生严重的码间干扰,而盲均衡技术能有效消除码间干扰。文中重点研究了基于MIMO通信系统的恒模盲均衡算法,并在此基础上提出了基于Sigmoid函数的变步长CMA均衡算法。该算法与传统方法的不同之处在于,该改进算法中所使用的步长因子能跟随均衡器的收敛情况自适应调整,且计算仿真结果表明,改进后的CMA算法能有效抑制噪声,且收敛速度快。

With greater data rate,the MIMO channel becomes to be frequency selective,with serious intersymbol interference at the receiving end caused by the multi-path and multi-user interference. The blind equalization technology can eliminate inter-symbol interference effectively. This paper focuses on the constant modulus blind equalization algorithm（CMA） in MIMO communication system and proposes an improved algorithm based on sigmoid function. Different from traditional methods,the proposed algorithm based on variable step size can change its step with the convergence of the equalizer. The simulation result shows that the algorithm has a better ability to control the noise and at higher convergence speed.