Distributed MVDR Beamforming for (Wireless) Microphone Networks Using Message Passing

In this paper we present a distributed algorithm for MVDR beamforming which is based on message passing. The message-passing algorithm performs generalized linear-coordinate descent (GLiCD) operations to exchange messages between neighboring microphone nodes, which converges increasingly fast as the noise correlation matrix becomes more and more diagonal. The algorithm makes use of a trade-off parameter which controls the off-diagonal energy of the noise correlation matrix. For the case the noise correlation matrix is truly diagonal, the performance of the GLiCD algorithm is equivalent to that of the delay-and-sum beamformer (DSB). The algorithm does not require any constraint on the network topology, is fully scalable and can exploit sparse network geometries, thereby making it suitable for distributed signal processing in large scale networks.