MIMO-OFDM系统中基于迭代MAP算法的RLS信道估计

RLS Channel Estimation via the Iterative-MAP Algorithm for MIMO-OFDM Systems

该文提出了一种适用于MIMO-OFDM系统的迭代最大后验概率(Iterative-MAP)信道估计算法。接收机利用MAP译码算法中的信息位和校验位软信息,经过非线性映射将信息反馈至信道估计模块,采用递归最小二乘(RLS)自适应滤波算法对信道时变状态参数进行跟踪,提高了信道估计的精度。仿真结果表明,该方法与最小二乘(LS)算法相比,估计的均方误差(MSE)和误帧率(FER)性能都有较大改善。

This paper proposes an iterative Maximum A Posteriori （MAP） probability channel estimation algorithm for MIMO-OFDM systems. The receiver employs the soft systematic bits and soft parity bits of MAP decoding and feeds them back to the channel estimator through nonlinear mapping. To track the time-varying channel, the estimator adopts the Recursive Least Squares （RLS） adaptive filtering algorithm so as to improve the accuracy of the estimation. Computer simulations show that the proposed algorithm can achieve much better performance than the conventional Least Squares （LS） channel estimation in both Mean Square Error （MSE） and Frame Error Rate（FER） .