Abstract:
In a cellular network, a cell-edge user usually suffers from poor quality of service
(QoS) and low signal-to-interference and noise ratio (SINR), This is due to low received
signal power as the propagation distance increase and high fading effects, which leads
to a considerable outage probability and low achievable data rate.
The performance of the cell-edge users is an essential issue in non-orthogonal multiple
access (NOMA) systems. In this paper, we investigate the performance of the Simulta neous Wireless Information and Power Transfer (SWIPT) cooperative non-orthogonal
multiple access (C-NOMA) system in half-duplex, decode and forward (DF), energy
harvesting (EH), and power splitting relay networks over different scenarios which are
characterized by Rayleigh fading channels and capacity advantage of maximum-ratio
combining (MRC) over selection combining (SC) technique analyzed. The system per formance of such networks is analyzed in terms of outage probability (OP), achievable
capacity, and sum throughput, in comparison to the non-cooperative non-orthogonal
multiple access and conventional orthogonal multiple access (OMA) system
In this paper, published research that focuses on the improvement of cell edge perfor mance is reviewed. We consider a two-user non-orthogonal multiple access system in
which the cell-center user act as an energy harvester and information relaying for the
cell-edge user. We analyze the capacity advantage transmit antenna selection (TAS)
policy at BS. To evaluate the performance of considered systems, we used a closed-form
expression for the OP of both cell-center and cell-edge users, in addition to that we
use Rayleigh fading channel, selection combining (SC), and maximum-ratio combining
(MRC) at the cell-edge user, and also use a gradient decent algorithm that finds The
optimal value of Power splitting(PS) coefficient, which maximize throughput for the
cell-edge user.
Matlab simulation of numerical results has shown a cooperative SWIPT-NOMA us ing MRC has decreased in OP 40% compared to non-cooperative NOMA, 25.98% com pared to cooperative NOMA without a direct link, and 9.02% compared to cooperative
SWIPT-NOMA with SC techniques. The optimal value of the β is between 0.1 to 0.3
from the simulation result. Cooperative SWIPT-NOMA with MRC also provides an
increase in achievable capacity, 66.12% compared to the conventional OMA system,
12.88% compared to the non-cooperative NOMA system, and a 2.18% improvement
over SC techniques. Cooperative SWIPT-NOMA with MRC has a sum throughput
improvement of 7.64% over the SC technique, 11.68% over the non-cooperative NOMA
system, and 15.58% over the conventional OMA systems at low SNR.
