Beam Design for Energy-Efficient Wireless Coverage of 5G mmWave Networks

This paper investigates beam design in a millimeter wave (mmWave) network, where some obstacles block the link between the base stations (BSs) and the user equipments (UEs). There is a single cell in an area where the UEs communicate with the single BS through a line of sight (LoS) link. To provide services in the network, synchronization signal blocks (SSBs) are transmitted by the BS in a fixed beam pattern. We aim at minimizing the transmit power by designing the beam while meeting the coverage requirement, which depends on the reference signal received power (RSRP) at the UEs. A non-convex power minimization problem is then formulated by jointly optimizing the beam directions, beam width and beam number subject to the coverage constraints. To resolve this problem, an alternating optimization (AO) based algorithm is proposed and the successive convex approximation (SCA) method is applied. The simulation results demonstrate that the proposed algorithm can significantly improve the performance of power consumption compared with the other two heuristic algorithms.