Dual‐ordered non‐orthogonal multiple access with decode and forward relaying

Cooperative non‐orthogonal multiple access (NOMA) system has demonstrated the ability to improve spectral efficiency, massive connectivity, and spectral efficiency. In this study, the authors propose a novel dual‐ordered NOMA in a decode and forward (DF) relaying network, where a dynamic channel ordering is considered at both source and relay nodes during the symbol transmission period. The proposed NOMA system uses instantaneous channel gain as the channel state information (CSI) measure for channel ordering of the NOMA users in contrast to the more popular statistical CSI measures. We have established the efficiency of the proposed method through investigation of three different performance metrics: outage probability, ergodic rate analysis, and fairness of the proposed scheme in a downlink NOMA network with DF relaying. The results obtained show superior performance of the double ordered NOMA as compared to the single‐ordered NOMA.