Robust Access Point Deployment and Adaptive User Assignment for Indoor Millimeter Wave Networks

Abstract

Millimeter wave (mmW) systems typically use beamforming techniques to compensate for the high pathloss. However, directional communications in the presence of uncertainty in user equipment (UE) locations and channel conditions make maintaining coverage and connectivity challenging. In this context, assuming that mmW access points (APs) use low complexity fixed directional antennas, we propose a joint optimization framework for AP deployment and UE assignment in indoor mmW networks. The goal of our optimization framework is to determine the minimum number of required APs, their optimal locations, their optimal beam directions, and their optimal assignments to individual UEs in order to ensure network-wide coverage and maximize the stability of mmW beams assigned to individual UEs. The network deployment decisions (i.e., the required number of APs, their placements, and their beam directions) are static and are taken before UE locations and channel conditions are revealed. The UE assignment decisions are taken under each realization of UE locations and channel conditions considering the availability and stability of the mmW beams. Our numerical results demonstrate the behavior of the proposed framework under various UE distributions and system parameters.