Resource optimization for cooperative SWIPT-NOMA systems with imperfect SIC

This paper investigates a cooperative non-orthogonal multiple access (NOMA) system designed for multiple users. It integrates simultaneous wireless information and power transfer (SWIPT) while accounting for the imperfections in successive interference cancellation (SIC). In this scenario, a nearby user functions as a relay for a more distant user. Through the utilization of a power splitting (PS) protocol, the nearby user adeptly manages both energy harvesting and decoding signals from users. A user pairing strategy is employed, aiming to guarantee a significant contrast in channel gains between users within each pair. Subsequently, the power allocation coefficients and PS factor for each cluster are derived to optimize the performance of nearby users and amplify the overall system throughput. This optimization takes into account the individual target rates of each user while accommodating the presence of imperfect SIC. Numerical results affirm the enhanced performance of the nearby user, showcasing greater system throughput and minimal outage probability compared to existing schemes, even in the presence of imperfect SIC.