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The asymptotic expressions of offloading outage probability are provided in the high signalвЂђtoвЂђnoise ratio regime. To evaluate the potential performance of IRS aided cooperative NOMAвЂђMEC, new closedвЂђform expressions of the offloading outage probability is deduced for a pair of users.

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When the direct links between the base station and the user are blocked, the offloading tasks will be refracted to the nearвЂђend user through the IRS and forwarded to the remote user, where the nearвЂђend user is equipped with an MEC server working at full duplex or half duplex mode. In this paper, an intelligent reflecting surface (IRS) assisted cooperative nonвЂђorthogonal multiple access and mobile edge computing (NOMAвЂђMEC) system is proposed, where a base station sends signals to users through the virtue of the IRS. In simulations, it is demonstrated that the theoretical results match well with the simulation results and the SOP of the proposed schemes is less than that of the conventional orthogonal multiple access scheme obviously. In order to gain more deep insights on the derived results, the asymptotic performance of the derived SOP is analyzed. Additionally, the closed-form expressions of secrecy outage probability (SOP) are derived for the proposed relayвЂ“antenna selection schemes. Under the condition that the channel state information of the eavesdropping channel is available or unavailable, two effective relayвЂ“antenna selection schemes are proposed. In order to reduce expense on radio frequency chains, selection combining (SC) is employed at both the relays and the users, whilst the eavesdropper employs either maximal-ratio combining or SC to process the received signals. This paper investigates relayвЂ“antenna selection to enhance physical-layer security of cooperative NOMA system in the presence of an eavesdropper, where multiple antennas are deployed at the relays, the users, and the eavesdropper. Secure transmission is essential for future non-orthogonal multiple access (NOMA) system. Monte Carlo simulations are present to verify the correctness of theoretical analyses that: (1) The outage probability of user n with pSIC is superior to that of orthogonal user, while the outage probability of user m is inferior to that of orthogonal user and (2) as the number of reflecting elements and Rician factors increases, the outage behaviors of RISвЂђNOMA networks are enhanced carefully. In addition, the system throughput of RISвЂђNOMA networks with ipSIC/pSIC is surveyed in detail. The impact of these parameters on outage behaviors of RISвЂђNOMA networks is also analysed. It indicates that the diversity orders are in connection with reflecting elements and Rician factors except the channel ordering. According to the approximate analyses, the diversity orders of user n with ipSIC/pSIC and user m are obtained in the high signalвЂђtoвЂђnoise radio regime.

More specifically, the exact and asymptotic expressions of outage probability for a pair of users, that is, the nearby user n and distant user m are derived, where the imperfect successive interference cancellation (ipSIC) and perfect SIC (pSIC) are taken into consideration. In this paper, the performance of RIS aided nonвЂђorthogonal multiple access (NOMA) networks with hardware impairments over Rician fading channels is investigated. Reconfigurable intelligent surface (RIS) has stimulated their potential applications for improving the performance of wireless communication networks.

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