Expectation maximization based detection for V-BLAST MIMO communication systems and performance evaluation

Maximum likelihood naturally arises as the target criterion for detection in many applications, as well as in layered space-time communications. Nevertheless, existing algorithms for maximum likelihood decoding have computational complexity that is not feasible for implementation in practical systems. Applying the expectation maximization algorithm to the maximum likelihood detection of layered space-time codes, we iteratively maximize the conditional log-likelihood of a single layer, rather than maximizing the intractable likelihood function of all layers. Computer simulations demonstrate the efficiency of the proposed detection scheme, in comparison to the well known nulling and cancelling detection scheme.