New look on relay selection strategies for full-duplex multiple-relay NOMA over Nakagami-m fading channels

By removing the orthogonal use of radio-resources, non-orthogonal multiple access (NOMA) has been introduced to improve spectral efficiency fifth generation (5G) and beyond networks. This paper studies system performance in a dual-hop multi-relay NOMA using decode-and-forward (DF) scheme over Nakagami-m fading channels. A group users is considered, i.e. near far which are decided by how strong these related channels are. Specifically, we obtain closed-form expression outage probability near/far when several relay selection schemes adopted for selecting best among M intermediate relays. As main finding, this introduces three strategies including two-stage selection, max-min power allocation based schemes. benefit, considered employ combining technique order signal transmissions an increased reliability context massive connections 5G wireless communications. conducting numerical simulations, evaluate impact number relays, factor, severity parameter on users. Finally, along with throughout delay-limited transmission mode provided via results necessary comparisons provided.