Performance Assessment of Millimeter-Wave NOMA System With Intelligent Reflecting Surface

Abstract

This paper analyzes the performance of millimeter-wave (mmWave) non-orthogonal multiple access (NOMA) system with the aid of an intelligent reflecting surface (IRS). We derive the outage probability (OP) expressions at two users D 1 and D 2 of the IRS aided mmWave-NOMA system (the IRS-mmWave-NOMA system in the following). We validate the derived expressions via computer simulations. By considering the Nakagami-m fading channels and the path loss model proposed for 5G standard in the IRS-mmWave-NOMA system, our results are more suitable in practical scenarios. Specifically, numerical results observe that even the carrier frequency is extremely high (f c = 90 GHz) and the transmitter-receiver distances are further than 50 m, the OPs at D 1 and D 2 can achieve 10 −4 when the transmit power of base station (BS) is 30 dBm (dB in the following). Moreover, the OPs at D 1 and D 2 with IRS are greatly lower than OPs without IRS. This result demonstrates the huge benefits of utilizing IRS in mmWave-NOMA system. In addition, we can use an IRS with larger number of reflecting elements to maintain the OP performance at D 1 and D 2 when the distances are increased and f c is higher. On the other hand, we should choose a suitable value of power allocation coefficients to obtain the same performance at D 1 and D 2 .INDEX TERMS Non-orthogonal multiple access, millimeter-wave, intelligent reflecting surface, moment function, outage probability.

Performance Analysis of Multiple-RIS-Based NOMA Systems

“…Consequently, the MS protocol is regarded as having the simplest implementation [30]. According to Liu et al [31], we make the following assumptions: the RISs contain N components, N R for reflection and N T for transmission, with N R þ N T ¼ N. In practice, in the context of IRS, a controller is often employed to dynamically adjust the phases of the reflecting elements [32]. This enables the IRS to optimize its beamforming capabilities and enhance the performance of the wireless communication system.…”