【摘要】 最小均方误差(MMSE)信道估计算法应用于MIMO-OFDM系统时将带来高计算复杂度且不易实现,根据这个问题,提出了一种基于期望最大化(EM)的线性最小均方误差(LMMSE)信道估计算法,并分析了该算法的性能.EM算法可以把多输入多输出(MIMO)信道估计问题转化为一系列单输入单输出(SISO)信道估计问题,避免了大规模的矩阵运算,简化了算法,提高了系统性能和估计精度,为进一步改善基于EM的LMMSE信道估计算法的性能,通过设计训练序列对EM迭代初值的计算方法进行了,改进,通过实验仿真表明改进后的方法提高了系统的性能.更多还原

【Abstract】 The channel estimation algorithm of minimum mean square error(MMSE)is of high computational complexity and is not easy to carry out when it is applied to multiple input multiple output with orthogonal frequency division multiplexing(MIMO-OFDM)systems.Aiming at these problems,an expectation maximum(EM)based linear minimum square mean(LMMSE)algorithm is proposed and the performance is analyzed.The EM algorithm can change multiple input multiple output(MIMO)channel estimation problem into a series of single input single output(SISO)channel estimation.This transformation can avoid large-scale matrix operation so as to simplify the algorithm and improve the performance of the system and the accuracy of the estimation.In order to enhance the performance of the EM-based LMMSE channel estimation,the initial value of the iterative EM algorithm is improved through designing the training sequences.The improved performance of the system is verified by several simulation experiments.更多还原