MIMO-OFDM iterative receiver design in multicell environments

In this paper, we consider an iterative receiver for multiple input multiple output (MIMO) orthogonal frequency division multiplexing (OFDM) systems when the co-channel interference (CCI) exists. In multicell envirnoments, the CCI is usually the OFDM signal from adjacent cells. Although the joint detection of the desired signal and CCI is desirable to effectively mitigate the CCI, it can be impractical due to prohibitively high computational complexity. Thus, a practical approach is to detect the desired signal only, while the CCI becomes a (colored) noise. This leads to an maximum likelihood (ML) based approach for the proposed iterative receiver, in which the estimation of the covariance matrix of the CCI and the MIMO channel is considered through a generalized expectation-maximization (GEM) algorithm.