Reduced Complexity Blind Layered Space-Time Equalization for MIMO OFDM Systems

This paper proposes a reduced complexity blind layered space-time equalization (LSTE) for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM). Blind source separation (BSS) combined with a vertical Bell Laboratories layered space-time (V-BLAST) scheme is used in a small portion of subcarriers to perform blind signal detection and channel estimation iteratively. In the remaining subcarriers the channel state information (CSI) is obtained by interpolation using the previously acquired CSI, and signal detection is subsequently carried out with a V-BLAST scheme. Compared to previous work where BSS is used in each subcarrier, the proposed system obtains similar performance while significantly reducing the computational complexity and improving the robustness to the propagation of permutation errors. Also, the performance of the blind LSTE can approach the ideal case with perfect CSI, by using a moderate number of iterations