Successive Interference Cancellation and MAP Decoding for Mobile MIMO OFDM Systems and Their Convrergence Behavior
Turbo equalization schemes based on minimum mean square error criteria available in the literature for Multiple Input Multiple Output (MIMO) systems are computationally expensive, as they require a relatively large matrix inversion. In this paper, the authors propose a sub-optimal, Successive Interference Cancelation (SIC) based Maximum A Posteriori (MAP) decoding in doubly dispersive channels for Orthogonal Frequency Division Multiplexing (OFDM) MIMO systems (SIC-MAP-MIMO). SIC-MAP-MIMO leverages on the soft feedback symbol estimate to remove the inter-carrier interference and co-antenna interference from the received data thus making the subsequent MAP decoding simple. Extrinsic information transfer chart analysis supplemented with numerical simulation results show that SIC-MAP-MIMO achieves comparable BER performance to similar equalization schemes but with significant computational savings.