Resource allocation for downlink joint space-time and power domain non-orthogonal multiple access

摘要

A quasi-orthogonal space-time block code (Q-OSTBC) has been proposed to achieve a better multiplexing-diversity tradeoff. With unequal diversity order of symbols, the code can effectively mitigate the error propagation in the successive interference cancellation (SIC) based detector for each user. As well known, non-orthogonal multiple access (NOMA) has been recognized as a promising technique for 5G networks due to its superior spectral efficiency, many connections, and user fairness. In this paper, we have multiplexed the space-time and power domains and combined the Q-OSTBC with NOMA to further improve the system throughput. Both optimal and suboptimal power allocation schemes have been designed to maximize the system rate with the total power constraint and the quality of service (QoS) constraint of the weak user. Simulation results have validated our theoretical claims, and also shown that the proposed algorithms can realize the efficient power allocation with very low computational complexity.