Topological Pilot Assignment in Large-Scale Distributed MIMO Networks

We consider the pilot assignment problem in large-scale distributed multi-input multi-output (MIMO) networks, where a large number of remote radio head (RRH) antennas are randomly wide area, and jointly serve relatively smaller users (UE) coherently. By artificially imposing structures on UE-RRH connectivity, we model network by partially-connected interference network, so that can be cast as topological management with multiple groupcast messages. Building upon such connection, formulate (TPA) two different ways respect to whether or not to-be-estimated channel connectivity pattern is known a priori . When it known, TPA low-rank matrix completion solved simple alternating projection algorithm. Otherwise, sequential maximum weight induced matching either mixed integer linear program yet efficient greedy With formulations problem, evaluate efficiency proposed algorithms under cell-free massive MIMO setting.