Performance Analysis of Cooperative Pattern Division Multiple Access (Co-PDMA) in Uplink Network

As a promising candidate non-orthogonal multiple access scheme for the fifth generation (5G) wireless communication system, pattern division multiple access (PDMA) has received considerable attention recently. Using pattern matrix (G_PDMA^[2,3], as an example, is used in this paper), PDMA directly maps the information bits of different users to radio resources, such as code, power, time and frequency, and space resource. PDMA can meet the requirements of massive connectivity and higher spectral efficiency for the 5G mobile network. In order to further improve transmission reliability and enhance the coverage, an uplink cooperative PDMA (Co-PDMA) scheme with half-duplex decode and forward relay is proposed. The analytical expressions of outage probability (OP) and sum data rate are derived to characterize the performance of the proposed scheme. The results show that the proposed Co-PDMA scheme achieves superior outage performance, with gains of 8 and 12 dB over the nonCo-PDMA and cooperative orthogonal multiple access (Co-OMA), respectively, @ OP = 0.1. Besides, the scheme is found to outperform two other schemes in terms of higher sum data rate and achieve an almost maximum 50% gain over Co-OMA when every user has the same target data rate.