A Message-passing Approach to Precoder Selection in Wireless Communication Networks

This paper addresses distributed techniques to the problem of precoder selection in a multi-cell scenario. This proposes an iterative method based on a message-passing procedure in factor graphs. A particular example of discrete precoder codebook is considered for transmission of a single data stream on two transmit antennas. For more realistic results, the wireless channel is modeled based on mea- sured data. Evaluations on the potential of such an approach in a wireless communication network are provided and its performance and convergence properties are compared with the greedy approach. Also, the output of the first iteration of the graph-based method is compared with greedy solution. Simulation results for the precoder selection example are presented and discussed, which show that the graph-based technique generally obtains gain in sum rate over the other approaches at the cost of a larger message size. Besides, the proposed method usually reaches the global optima in a efficient manner in terms of computational complexity and signaling load.