On the Performance of PDMA With Decode-and-Forward Relaying in Downlink Network

This paper studies the application of cooperative techniques for pattern division multiple access (PDMA) in downlink (DL) network. More particularly, the performance of joint decode-and-forward (DF) relaying and PDMA (DF-PDMA) is investigated over Rayleigh channel, where the direct links are existent between the base station and users. To characterize the performance of the considered scenarios above, the closed-form expressions for outage probability and sum data rate are derived. Based on the derived results, the diversity orders achieved by users are obtained. The analysis results manifest that those users with DF relaying can achieve higher diversity order, in addition, the users selecting the PDMA pattern with higher column weight can further obtain higher diversity order. Simulation results unveil that DF-PDMA outperforms PDMA and orthogonal multiple access with DF relaying (DF-OMA) in terms of outage probability and system throughput. It is also worth noting that DF-PDMA can provide better fairness compared to DF-OMA.