An Improved Bayesian EM Channel Estimator for MIMO-OFDM Systems
MIMO-OFDM系统中一种改进的Bayesian EM信道估计器

An improved Bayesian EM channel estimator is proposed for MIMO-OFDM systems. Using the candidates list of the List Sphere Decoder (LSD) and a prior information from the decoder, the approximations of the soft decision symbols in the conventional EM channel estimator are modified. The a posteriori probabilities, the first and second moments of the soft symbol decisions are calculated more accurately. Based on the prior information of the channel measured by the initial estimation, a new Maximum A Posteriori (MAP) estimation of the channel impulse response, which considers the posteriori cross-correlation of the soft symbols, is obtained. Simulation results show that the newly proposed BEM algorithm outperforms conventional EM estimation schemes both in terms of BER and mean square estimation error.