MAP Source Separation using Belief Propagation Networks

In this paper we continue our treatment of source separation based on dynamic sparse source signal models. Source signals are modeled in frequency domain as a product of a Bernoulli selection variable with a deterministic but unknown spectral amplitude variable. The Bernoulli variable is modeled by a first order Markov process with transition probabilities learned from a training database. We consider a scenario where the mixing parameters are estimated by calibration. We derive the MAP signal estimators and show that the optimization problem reduces to a Belief Propagation Network simulation. We also present preliminary separation performance results using TIMET database.