Optimized Wireless Energy Harvesting Sensor Network with Backscatter Communication and Beamforming

This paper formulates and solves a joint-optimization problem whose objective is to maximize the sum-throughput of a wireless powered communication network (WPCN) with radio frequency (RF) energy harvesting and backscatter communication using a beamforming hybrid access point. A new multi-sensor blind adaptive beamforming with combination protocol (MS-BABF/combo) is proposed and analyzed. Numerical results show that the jointly optimized MS-BABF/combo protocol delivers up to 48.8% and 26.4% increase in sum-throughput compared to a single input, single output configuration and the MS-BABF with time-switching (MS-BABF/TS) protocol, respectively, in a dynamic environment. The MS-BABF/combo protocol also considerably decreased the sensor dropout rate compared to the MS-BABF/TS protocol from 1.0% to 0.43% at 7.5m. The findings are significant for future widespread adoption of WPCN systems powered by RF energy sources in the real world by increasing the amount of harvested energy and system achievable data rate.