Impact of remote radio head positions on the performance of distributed massive MIMO system with user mobility

The combination of interference mitigation, small cells and massive multiple-input multiple-output (MIMO) is the ultimate vision of future wireless technology. The combination of these three make a distributed massive MIMO system, in which the Base Station (BS) antennas are spread out over a large area, offering high coverage probability and less inter-cellular interference for cell-edge users as compared to a collocated massive MIMO system. The optimal configuration for remote radio heads (RRHs) in distributed massive MIMO is a challenge, which needs to be addressed. In this paper, we consider two scenarios for RRHs placement in a multi-cell distributed massive MIMO system. In the first case, RRHs are evenly placed on a circle of optimum radius. In the second case, RRHs are spatially distributed according to Poisson Point Process (PPP). The effect of both these layouts on different performance metrics including coverage, mobility, cost of deployment and interference is analyzed. Our work shows that placement of optimal circularly distributed RRHs outperform PPP distribution of RRHs in a multi-cell setting.