Joint Beam and Power Control for Millimeter-Wave Multi-Flow Multi-Hop Networks

This letter investigates the joint beam and power control in multi-flow multi-hop networks with millimeter-wave (mmWave) directional transmissions. To guarantee fairness among multiple data flows, an optimization problem is formulated to maximize the minimum of the achievable rates for all flows by jointly optimizing three-dimensional (3D) antenna boresights and transmit powers. To address the non-convex problem, we employ the block coordinate descent (BCD) method to solve two subproblems iteratively. Specifically, each iteration involves solving the transmit power control subproblem by using successive convex approximation (SCA) techniques. Then, suboptimal antenna boresights, including the azimuth and elevation angles for multiple transmitters, are obtained by using a tailored particle swarm optimization (PSO) algorithm. The simulation results reveal the effectiveness and superiority of the proposed algorithm in enhancing the minimum end-to-end achievable rate (E2EAR) compared to the benchmark schemes.