Channel Estimation Using Adaptive Filters in MIMO-OFDM Systems

Since accurate channel state information is essential to diversity combination, coherent detection and decoding in a wireless MIMO-OFDM system, this paper presents a channel estimation method using adaptive filters in wireless MIMO-OFDM systems. Though this method presupposes no prior knowledge of channel statistics, it can track or estimate time-varying channel parameters instantaneously with the help of pilot symbols and adaptive filters. Simulation results have proved this method using adaptive filters has better performance than another method based on a least-square (LS) algorithm. And the method using a least-mean-square (LMS) filter has lower computational complexity than that using a recursive-least-squares (RLS) filter. However, the channel estimation method using the RLS filter has better performance and faster convergence than that using the LMS filter. Therefore, we can select a fitter channel estimation method using different filters according to its characteristics