Sum-Throughput Maximization in Wireless Sensor Networks With Radio Frequency Energy Harvesting and Backscatter Communication

This paper formulates and solves optimization problems whose objective is to maximize the sum-throughput of wireless sensor networks with radio frequency (RF) energy harvesting (EH) and backscatter communication. The paper proposes and analyzes three protocols for maximizing the sum-throughput; namely, the time-division with downlink data decoding protocol, hybrid power splitting/data decoding protocol, and backscatter-enabled combination protocol. The time-division protocol optimizes a wireless powered communication network (WPCN) with a two-way communication link between the sensors and a hybrid access point. The hybrid protocol optimizes a WPCN with a power splitting downlink data decoding phase. The backscattered-enabled combination protocol optimizes a WPCN with a power splitting downlink data decoding phase and backscatter communication enabled sensors. Numerical results show that the hybrid and combination protocols deliver up to 14.5% and 30.5% increase in sum-throughput, respectively, compared with the reference time-switching RF EH protocol in a dynamic environment. The findings are significant for the 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.