Secure and reliable SWIPT in active RIS-aided downlink NOMA with hardware impairments

Abstract

Abstract Due to growing system complexity and the vulnerability of wireless transmissions to information leakage, maintaining secure and private communication in sixth-generation (6G) networks continues to be a significant problem. By enabling wireless power transfer to distant Internet of Things (IoT) devices while retaining low latency and high spectral efficiency, power beacons (PBs) have been acknowledged as an efficient way to increase energy efficiency simultaneously. However, non-ideal components like amplifiers, oscillators, and mixers unavoidably create hardware impairments (HIs), which can deteriorate security and dependability in practical deployments. To overcome these challenges, this work proposes a novel framework that integrates active reconfigurable intelligent surfaces (ARIS) into a secure downlink non-orthogonal multiple access (NOMA) system. The base station (BS) is powered by an energy-harvesting device with PB assistance. In contrast to previous research, the approach specifically takes into account the influence of HIs. To assess system performance, closed-form formulae for effective secrecy throughput (EST), intercept probability (IP), and outage probability (OP) are generated. The conclusion is supported by simulation results, which demonstrate that a higher signal-to-noise ratio (SNR) decreases OP while raising IP. Moreover, the proposed ARIS-NOMA scheme outperforms conventional ARIS-orthogonal multiple access (OMA) approaches, providing valuable insights for secure wireless system design.