Multi-BD Symbiotic Radio-Aided 6G IoT Network: Energy Consumption Optimization with QoS Constraint Approach

Abstract

<p>Symbiotic radio (SR) is a novel paradigm in cognitive ambient backscatter communication, which makes the connection of devices without the need to reallocation of the frequency spectrum and complex energy infrastructure and so, can turn a 6G network into a green communication. In the system model of this paper, the base stations (BSs) with the active antennas, symbiotic backscatter devices (SBDs) and symbiotic user equipment (SUE) are considered. The main purpose is to minimize the energy consumption (EC) in the SR network and increase energy efficiency (EE) by taking into account to fulfillment of the minimum required throughput for SBDs. To this end, we introduce a new scheduling system called Timing SR (T-SR) to optimal resource allocation between SBDs. In this system, SBDs harvest energy from ambient signals and then send their information without interfering with each other, even in simultaneous transmission, to SUE by using the carrier of its signal. The main optimization problem has non-convex objective functions and constraints. To solve it, we use the novel mathematical methods called conic quadratic representation (CQR) and sequential quadratic (SQ) techniques. Finally, simulation results demonstrate the superiority of the proposed method compared to other outlined schemes in reducing the EC.</p>