Fairness-Aware Resource Allocation in Full-Duplex Backscatter-Assisted Wireless Powered Communication Networks

Rui Jiang,Xiaoming Wang,Meihua Liu,Youyun Xu,Luis Castedo

doi:10.1155/2021/8842562

Abstract

In this paper, we introduce a full-duplex backscatter-assisted wireless powered communication network (FDBA-WPCN) with a full-duplex access point (FAP) and multiple energy harvesting wireless devices (WDs). The communication mode is a combination of backscatter communication (BC) and harvest-then-transmit (HTT). The entire time period of network is divided into energy harvesting/backscattering (EHB) period and information transmission (IT) period. In the EHB period, each WD either reflects information to the FAP by backscatter or harvests energy to prepare for the IT period. In the IT period, the WDs use their harvested energy to transmit information to FAP in time division multiple access (TDMA). However, under the setting, WDs with different distances from FAP will encounter unfairness in throughput due to the round-trip path loss in backscatter and the doubly near-far problem in HTT. To overcome the drawback, an optimization problem is considered to maximize the sum throughput under the condition of ensuring throughput fairness. By using convex optimization techniques, we obtain the optimal time allocation and the maximum same throughput of each WD. Comparing to the other two benchmark schemes, the simulation results prove the superiority of our proposed method.

Highlights

With the rapid evolution of the Internet of Things (IoT) and the proposal of green communication, energy harvesting (EH) technology for power-constrained wireless devices (WDs) has aroused great concerns in academia and industry
Motivated by the advantages of the above research, this paper investigates an FDBA-wireless powered communication networks (WPCNs) with an FD access point (FAP) and multiple WDs, where each WD is equipped with HTT module and backscatter communication (BC) module
The distance between full-duplex access point (FAP) and WDi is assumed as ð10 + ð10/KÞ × iÞm, which shows that the distances of different branches are different

Summary

Introduction

With the rapid evolution of the Internet of Things (IoT) and the proposal of green communication, energy harvesting (EH) technology for power-constrained wireless devices (WDs) has aroused great concerns in academia and industry. EH replaces traditional battery-powered or wired power supply methods and enables WDs to achieve contact-less and sustainable power supply. It can can extend the life of the WDs and reduce green gas emissions [1, 2]. WPCNs were first studied in [4], where the author proposes a typical transmission protocol, named harvest--transmit (HTT). WDs may require a long time to harvest enough energy for WIT in this process, which can reduce the time for information transmission (IT). In order to solve this problem, many experts have turned their attention to backscatter communication (BC) in recent years [5,6,7]

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Results

Conclusion