Impartial SWIPT-Assisted User Cooperation Schemes

TL;DR

This paper introduces an impartial SWIPT-assisted user cooperation scheme for NOMA systems that improves outage probability and diversity metrics, and compares its performance with OFDMA frameworks.

Contribution

It proposes a novel impartial cooperation mechanism using SWIPT in NOMA, enhancing system performance over traditional methods.

Findings

IUCM outperforms partial cooperation in outage probability and diversity.

Incorporating IUCM into OFDMA preserves diversity order.

IUCM in OFDMA achieves the same outage probability as in NOMA under ideal relaying conditions.

Abstract

In this paper, we propose an impartial simultaneous wireless information and power transfer (SWIPT)-assisted cooperation mechanism for a non-orthogonal multiple access (NOMA) downlink scenario. Specifically, both a cell-center user and a cell-edge user apply the power-splitting technique and utilize the harvested energy to forward the other user's information on the premise of successful decoding of their own information. Both analytical and numerical results show that the proposed impartial user cooperation mechanism (IUCM) outperforms the traditional partial cooperation mechanism in terms of outage probability, diversity order and diversity-multiplexing trade-off (DMT). For comparison, we further incorporate the IUCM into an orthogonal frequency-division multiple access (OFDMA) framework, which is shown to preserve the same diversity order, while has a worse but more flexible DMT performance in comparison with the IUCM in the NOMA framework. Although the IUCM in OFDMA has a worse outage performance, it is proved that it has the same optimal system outage probability with the IUCM in NOMA when the relaying channel between the two users is error-free.