Tongxin xuebao (Jan 2007)
Channel estimation method for MIMO-OFDM systems based on pilots and modified Kalman filter
Abstract
A combined channel estimation method of time-frequency-selective fading channels in MIMO-OFDM systems was proposed.The time-varying channel was modeled as an autoregressive(AR) process and a low-dimensional Kalman filter based on pilots was used to estimate the AR parameters,and the LS(least square) algorithm was adopted to track the time-varying channel fading factors.The Kalman estimator explored the time-domain correlation of the channel,and a minimum mean square error(MMSE) combiner was used to modify the Kalman estimates.The proposed solution could reduce the complexity of the high-dimensional Kalman filter and track the channel both in frequency and time domains.The simulation results show that this method improves the LS estimates and has a comparable performance to the com-plex high-dimensional Kalman channel estimation method.