Power Consumption Minimization for Uplink NOMA With Finite Blocklength Gaussian Coding

In light of the demands of green communications and latency constraints in 5G, this paper investigates the resource allocation to minimize the power consumption for 2-user uplink non-orthogonal multiple access (NOMA) schemes with finite blocklength codes. In contrast to the existing research, we consider the achievable bound developed with the finite blocklength Gaussian shell codes (FBGSC) as it is greater than the widely used i.i.d. Gaussian achievable bound. To sufficiently explore the potential of NOMA, three typical 2-user uplink NOMA schemes are investigated in this paper, in terms of the classical power domain NOMA, rate splitting multiple access (RSMA) and NOMA with joint decoding (NJD). Simulation results indicate that with FBGSC, NJD always outperforms the other two schemes. In addition, it is found that, with FBGSC, RSMA outperforms NOMA only if the channel quality difference is small. To the best of our knowledge, we are the first to investigate uplink NOMA and RSMA with the shell bound developed by Scarlett (2017), which is the state of the art for their corresponding channels in the finite blocklength regime. Besides, we are also the first to investigate the power/energy-efficient transmission for all these three NOMA schemes with the shell codes.