Resource Allocation in Multi-User NOMA Wireless Systems

Non-orthogonal multiple access (NOMA) has been considered as a key candidate technology for 5G wireless systems due to its superior spectral efficiency and system capacity. With the ever-development of wireless body sensor networks (WBSNs) and wireless communications, supporting real-time communications in the telemedicine communication becomes a very important challenge. In this article, our goal is to maximize the overall system throughput by optimizing sub-band allocation and power allocation, thereby improving real-time performance in telemedicine communications. Assuming that the base station could obtain perfect channel state information (CSI), we propose a suboptimal sub-band allocation algorithm with low complexity. In the power allocation scheme, the closed-form expressions of power allocation factors for multiplexed users on each subband are obtained based on the Karush-Kuhn-Tucker (KKT) optimality conditions. Simulation results demonstrate that the proposed resource allocation scheme is closest to the ideal subband allocation based on exhaustive search and is superior to other schemes.