Angle-domain MAP channel estimation algorithm by singular value decomposition for MIMO-OFDM systems

Maximum a posteriori probability (MAP)channel estimation algorithm needs to invert large-size matrices when it is applied to multiple-input multiple-output with orthogonal frequency division multiplexing (MIMO-OFDM)systems. And the data transmission efficiency will be reduced with the increasing number of transmit antennas. To deal with these problems, an angle-domain MAP algorithm based on singular value decomposition (SVD)is proposed. The proposed algorithm decomposes MIMO channel into a series of single- input-single-output (SISO) channels in the process of expectation maximum (EM). Meanwhile, the method of SVD avoids large-scale matrix inversion. Depending on the spatial independence of MIMO channel in inrut single-output angle domain, most significant taps (MST)technique is used to enhance the performance of estimation. Besides, to improve the data transmission efficiency and further the performance of estimator, joint estimation is carried out over multiple OFDM symbols. Simulation results indicate the effectiveness of the proposed algorithm. ©2009 by Editorial Department of Chinese Journal of Radio Science.