“…In this section, we briefly review the best Bayesian based receiver in the literature, Expectation Propagation (EP) receivers [11]- [14], [19], [20], which is a combination of Bayesian and MMSE concepts. The main idea of the EP is to iteratively approximate the distribution of a random transmitted symbol vector, x by using a Gaussian probability distribution function (PDF) approximation based on the received signals y, p (t) (x|y), and a pair of tuning parameters, (λ (t) , γ (t) ) which are obtained from the exponential family distributions [17].…”