An Adaptive Mode Selection Mechanism for Hybrid Active and Passive Communications

In this paper, we propose an adaptive mode selection algorithm for a hybrid active and passive communication system, where the communication paradigm of the wireless-powered communication network (WPCN) is referred to as the active mode, while ambient backscatter (AB) is applied for the passive mode. Specifically, the proposed algorithm switches between the active and passive modes by simultaneously considering both energy harvesting and signal-to-noise ratio (SNR) conditions. Besides, to further improve the system's reliability, we adopt the rate-adaptive technique in passive mode, allowing devices to choose an appropriate rate for data transfer when performing backscattering. We also introduce analytical models to characterize the performance of the proposed mode selection algorithm. Simulation results validate the analysis and indicate that the proposed mode selection algorithm has the advantage in terms of both success probability and average throughput.