Partial cooperative NOMA for improving outage performance of edge users

Providing reliable service to cell edge users has been a practical challenge for network operators due to the deep fading effects and limited base station (BS) resources. The low received signal strength causes the Quality of Service (QoS) degradation of the cell edge users and hence demands appropriate solutions to improve the user connectivity. To address this issue, this article proposes a two-tier partial cooperative relaying scheme, deployed in a non-orthogonal multiple access (NOMA)-based downlink network that serves the edge users with the minimum required QoS. Comparative performance analysis has been presented for two relaying schemes: amplify-and-forward (AF) and partial decode-and-forward (DF) in terms of outage probability and overall sum rate of the edge users. Additionally, the maximal ratio combining (MRC) diversity technique is integrated with the relaying network to further enhance the QoS of cell edge users. The impact of successive interference cancellation (SIC) on the outage performance has been thoroughly investigated. It has been established through extensive simulation that the partial DF technique is a promising relaying technique to improve the overall performance of cell edge users.