# Performance Analysis of NOMA-based Cooperative Relaying in {\alpha} - {\mu} Fading Channels

## TL;DR

This paper evaluates the performance of NOMA-based cooperative relaying systems over alpha-mu fading channels, demonstrating superior spectral efficiency and analyzing the impact of channel parameters on system performance.

## Contribution

It provides a novel analytical framework for evaluating CRS-NOMA performance over alpha-mu fading, including closed-form expressions and asymptotic analysis.

## Key findings

- CRS-NOMA outperforms CRS-OMA in spectral efficiency at high SNR.
- Performance depends on alpha and mu parameters of fading channels.
- Asymptotic analysis links diversity order to channel parameters.

## Abstract

Non-orthogonal multiple access (NOMA) is widely recognized as a potential multiple access technology for efficient radio spectrum utilization in the fifth-generation (5G) wireless communications standard. In this paper, we study the average achievable rate and outage probability of a cooperative relaying system (CRS) based on NOMA (CRS-NOMA) over wireless links governed by the $\alpha$-$\mu$ generalized fading model; here $\alpha$ and $\mu$ designate the nonlinearity and clustering parameters, respectively, of each link. The average achievable rate is represented in closed-form using Meijer's G-function and the extended generalized bivariate Fox's H-function (EGBFHF), and the outage probability is represented using the lower incomplete Gamma function. Our results confirm that the CRS-NOMA outperforms the CRS with conventional orthogonal multiple access (CRS-OMA) in terms of spectral efficiency at high transmit signal-to-noise ratio (SNR). It is also evident from our results that with an increase in the value of the nonlinearity/clustering parameter, the SNR at which the CRS-NOMA outperforms its OMA based counterpart becomes higher. Furthermore, the asymptotic analysis of the outage probability reveals the dependency of the diversity order of each symbol in the CRS-NOMA system on the $\alpha$ and $\mu$ parameters of the fading links.