Outage analysis of cooperative NOMA system with imperfect successive interference cancellation and channel state information over Rayleigh fading channel

Abstract

Summary Cooperative communication is a significant technology for fifth generation (5G) and beyond wireless communication to improve the quality of service (QoS) in massive networks. In addition, it serves as a promising candidate along with non‐orthogonal multiple access (NOMA) scheme to increase the spectral efficiency. Conventionally, cooperative‐NOMA (C‐NOMA) systems are analysed by assuming perfect successive interference cancellation (SIC) and imperfect SIC (I‐SIC) over Rayleigh, Rican, α−μ, Hoyt fading channels, and so on. In this paper, near–far relay (NFR) C‐NOMA system is analysed aiding perfect SIC, perfect channel state information (CSI), imperfect (I‐CSI) and (I‐SIC) over Rayleigh fading channel. Initially, we derive analytical expressions of outage probability (OP) by considering I‐SIC and I‐CSI for NFR‐C‐NOMA system. The accuracy of analytical results is verified through Monte Carlo (MC) simulations. Interpretation of the results conveys that I‐CSI and I‐SIC have a substantial impact on OP in NFR‐C‐NOMA scheme and existing schemes. Later, we examined impact on OP in NFR‐C‐NOMA by varying relay position, target rate of users and jointly considering the I‐SIC, I‐CSI. Further, it is also observed that the NFR‐C‐NOMA scheme shows better outage performance than state‐of‐the‐art schemes.

Enhancement of outage probability for down link cooperative non-orthogonal multiple access in fifth-generation network

“…The performance of a near-far relay C-NOMA system is explored using a Rayleigh fading channel, perfect and imperfect channel state information, and SIC, albeit only for a single user [18]. The usage of a half-duplex MIMO C-NOMA system with just a partial grasp of the channel state, as well as outage probability (OP) over Nakagami-m fading channels, is explored in [19]. The results, on the other hand, showed that the power allocation coefficients (PLCs) of users who were physically close to the BS were all assigned the same value.…”

“…Here is a quick rundown of our most significant contributions: − The OPs for the 2 users' NOMA and C-NOMA systems are generally represented in closed form by theoretical analysis with varying distances and PLCs. However, the simulation demonstrates that the derived OP expressions are more exact than those in [19]. − This paper proposes an opportunistic suboptimal relay selection technique that considers both users.…”