Exploiting macro-diversity in cellular networks using the sum-product algorithm

Abstract

We present a distributed macro-diversity algorithm for the uplink process in a cellular network, where base stations cooperate via message-passing to improve signal quality. We show that the cellular network can be modeled as a factor graph with loops and a simple distributed cooperative scheme for base stations can be derived from the sum-product algorithm. Assuming Gaussian signaling, we analyse the convergence of the algorithm and show its dependency on cellular system parameters such as the intercell interference, the signal-to-noise (SNR) ratio and the network size. We show that the algorithm converges if the intercell interference level is below some threshold, which is dependent on th..