Backscatter Cooperation in NOMA Communications Systems

In this paper, a backscatter cooperation (BC) scheme is proposed for non-orthogonal multiple access (NOMA) downlink transmission. The key idea to the surplus power of received signals at one user enhance reception who cannot recover its information. To evaluate performance BC-NOMA scheme, three benchmark schemes are introduced, which include non-cooperation (NC)-NOMA conventional relaying (CR)-NOMA and incremental (IR)-NOMA scheme. For all these schemes, outage performance, expected rate, diversity-multiplexing trade-off (DMT) analyzed. Additionally, optimal allocation maximize rate in high signal-to-noise ratio region derived. theoretical results show that can both transmission reliability (outage performance) effectiveness (expected rate) compared with NC-NOMA. Furthermore, representative numerical presented validate results. It shown unlike two relaying-based cooperative (CR/IR-NOMA), improve cost without impairing spectrum efficiency, makes backscattering an appealing solution NOMA downlinks.