User Cooperation in Wireless Powered Communication Networks

TL;DR

This paper introduces a user cooperation scheme in wireless powered communication networks that enhances throughput and fairness by allowing a nearer user to relay information for a farther user, optimizing time and power allocations.

Contribution

It proposes a novel user cooperation method in WPCNs that jointly optimizes energy transfer, information transmission, and relaying to improve throughput and fairness.

Findings

User cooperation improves throughput in WPCNs.

Optimized resource allocation enhances user fairness.

Simulation confirms effectiveness of the proposed scheme.

Abstract

This paper studies user cooperation in the emerging wireless powered communication network (WPCN) for throughput optimization. For the purpose of exposition, we consider a two-user WPCN, in which one hybrid access point (H-AP) broadcasts wireless energy to two distributed users in the downlink (DL) and the users transmit their independent information using their individually harvested energy to the H-AP in the uplink (UL) through time-division-multiple-access (TDMA). We propose user cooperation in the WPCN where the user which is nearer to the H-AP and has a better channel for DL energy harvesting and UL information transmission uses part of its allocated UL time and DL harvested energy to help to relay the far user's information to the H-AP, in order to achieve more balanced throughput optimization. We maximize the weighted sum-rate (WSR) of the two users by jointly optimizing the time and power allocations in the network for both wireless energy transfer in the DL and wireless information transmission and relaying in the UL. Simulation results show that the proposed user cooperation scheme can effectively improve the achievable throughput in the WPCN with desired user fairness.