A framework to optimize the frame duration and the beam angle for random beamforming of mmWave mobile networks

Abstract

Random Beamforming (RBF) for mmWave systems has been proven to provide optimal performance for downlink MIMO systems with respect to the number of users and the number of antenna elements in the base station. The mobility of User Equipment (UE) and its effect on the overall system capacity has been studied as well. The duration of each frame transmitted between the Base Station (BS) and any UE depends largely on the mobility state of the UE. Static UE can receive frames with any size and duration (to achieve the optimal sum rate performance), but mobile UE is limited to a specific frame duration before that UE gets out of the narrow beam coverage area. Beam angles used by the RBF is another application specific factor in the network design and its optimization for specific conditions is required to ensure providing the best achievable throughput to each user in the network. This work is suggesting a framework to optimize the frame duration and the beam angle for each mobility model with different outage probability thresholds (when the UE is moving out of the beam coverage area during transmission or reception). Convex optimization is used as the outage probability has been proven to monotonically increase with both the frame duration and the beam angle.