Iterative MAP receiver for interference suppression in SDM/OFDM systems

In this paper, we propose a reduced complexity iterative algorithm for joint maximum a posteriori (MAP) detection and interference suppression in orthogonal frequency division multiplexing (OFDM)-based space division multiplexing (SDM) systems. The receiver employs an iterative architecture where each iteration stage consists of the estimation of channel/covariance for co-channel interference (CCI) and the MAP detection that suppresses interference while detecting the data. The interference suppression is performed in the MAP detection by whitening the interference through combining the estimated covariance with the conventional MAP detection metric. Extensive simulations demonstrate that the proposed scheme dramatically improves the performance compared to that of the iterative MAP scheme without the suppression. Furthermore, it can effectively suppress both synchronous and asynchronous CCI without any a priori information on the CCI.