Joint Transmission Scheduling and Power Allocation in Wirelessly Powered Hybrid Radio Networks

Abstract

In this paper, we consider a multi-user hybrid radio network consisting of both conventional active radios that transmit information by self-generated carrier signals and backscatter radios that modulate information on ambient RF signals. All users are wirelessly powered by a power beacon station (PBS) emitting unidirectional RF signals. We assume that each user in the hybrid radio network can schedule its data transmissions in two radio modes, which provides extra degree of freedom for sum throughput maximization. To exploit the radio diversity, we propose a joint optimization of each user’s transmission scheduling in two radio modes and the PBS’ power allocation for different users. We show that the proposed optimization admits a convex reformulation, efficiently tractable by a centralized algorithm at the PBS. Moreover, we propose a distributed solution that iterates between two sub-problems, i.e., power allocation at the PBS and transmission scheduling at individual users, with reduced computational complexity and guaranteed convergence. Our simulation results verify that two radio modes can complement each other in data transmissions, bringing significant improvement to the sum throughput performance of the hybrid radio network.