Enhancing security and novel user-clustering with energy harvesting and coded cooperation in PD-NOMA

This study introduces a low-complexity, short-code-based strategy that combines energy harvesting for power domain non-orthogonal multiple access (PD-NOMA) techniques. Due to its non-orthogonal nature, PD-NOMA is relatively more exposed to security vulnerabilities, rapid battery depletion in users due to multi-level SIC, and significant outage probability in congested environments. The presented work uses coded cooperation and short block-length codes to make it harder for unlicensed users to manipulate or steal the data of licensed users. This makes it less likely that unlicensed users will be able to find and decode data belonging to licensed users in the NOMA system. To optimize performance and reduce the frequent outage probability in the NOMA system, we developed a novel user clustering technique. Due to multi-level successive interference cancellation (SIC) at the cell center, users’ batteries quickly drain out in congested NOMA networks, leading to their declaration as energy-constrained. To overcome this issue, we use simultaneous wireless information and power transfer (SWIPT) at user-located cell centers based on the received radio frequency signals. Furthermore, it allows cell-center users to assist cell-edge users through the coded multi-user cooperation (coded Cop-PD-NOMA) technique, thereby enhancing the base station’s (gNodeB) network coverage. During the validation process, the proposed design offers secure NOMA communication, a novel user-clustering technique, and the application of SWIPT to cooperation in the PD-NOMA infrastructure. Bit-error rate (BER) and outage probability (OP) tests show that novel user-clustering and multiuser-coded Cop-PD-NOMA outperform single-user cooperation. Simulation results show that the proposed approach significantly reduces the outage probability (OP) and improves bit-error-rate (BER) performance by approximately 6.5 dB, which is only 2.5 dB in single-user cooperation.