一种新的基于导频的MIMO-OFDM信道估计方法

A new pilot-aided channel estimation for MIMO-OFDM systems

提出了一种适用于时变衰落信道的MIMO-OFDM系统的组合信道估计方法。该方法利用优化导频和基于梯度的可变遗忘因子的改进RLS算法进行信道估计。此外,采用基于MMSE(minimum mean square error)的合并器对改进RLS算法的估计结果做了进一步修正。仿真结果表明,这种改进的RLS算法较传统的RLS算法能够更有效地跟踪时变衰落信道的变化;在相同条件下,该组合算法能够提高系统性能,获得更小的BER(bit error rate)。

In this paper a new pilot- aided channel estimation for MIMO-OFDM systems is proposed for time - varying fading channels. The gradient - based variable forgetting factor RLS algorithm is presented to track time-varying channels. This improved RLS algorithm produces much smaller MSE and hence provides better channel estimation. Besides, a minimum mean square error （MMSE） combiner is also used to modify the channel estimates obtained by the improved RLS algorithm. The results show that the proposed algorithm has better performance than the classical RLS algorithm in tracking time - varying fading channels and it also help obtain lower bit error rate （BER） for MIMO- OFDM systems.