Joint Optimization for Traffic-Offloading and Resource-Allocation Over RF-Powered Backscatter Mobile Wireless Networks

We develop the joint optimization schemes for traffic-offloading and resource-allocation over radio-frequency (RF) powered backscatter-based mobile wireless networks, where a macro-cell base station (BS), several small-cell access points (SAPs), and multiple energy harvesting (EH) mobile users (MUs) co-exist. Optimizing MUs' network access (via traffic-offloading) and system resource-allocation, we aim to minimize MUs' energy consumption by using low-energy consumption of backscatter. First, we consider the scenarios when short-range ambient backscatter (AB) communication (e.g., over several meters) is employed, enabling MUs to access nearby SAPs via ambient backscatter RF signals for data transmission. Using the alternating directions method of multipliers (ADMM), we develop a distributed traffic-offloading and resource-allocation scheme. Then, we focus on traffic-offloading and resource-allocation by adopting the concurrent AB (CAB) transmission, where multiple MUs can backscatter data concurrently to further reduce energy consumption. Moreover, we also use long-range bi-static backscatter (BB) communication (e.g., over 270-meter distance) for data transmission between MUs and BS, and then MUs can convey data by backscattering RF signals radiated from dedicated carrier emitters. Then, we study the joint traffic-offloading and resource-allocation when AB and BB communications are adopted by MUs accessing SAPs and BS, respectively. Finally, the numerical analyses validate and evaluate our developed schemes, showing their good convergence performances and significant reduction in energy consumption of MUs through backscatter communications.