Outage analysis for user pairing based downlink C-NOMA network with receiver diversity techniques over η-μ fading channel

In this paper, a novel downlink cooperative non-orthogonal multiple access scheme (C-NOMA) is proposed with various receiver diversity combiner techniques, such as maximal-ratio-combiner, equal gain combiner and selection combiner technique over η - μ fading channel. In addition, a user pairing is deployed for the proposed system model to reduce system complexity. To be more specific, to serve NOMA scheme, two users are selected out of multiple users in the proposed system model. The mathematical expressions of outage probability (OP) for the selected users are derived with M branch diversity combiner over η - μ fading channel, thereby the outage of the user pairing is obtained and analysed. Furthermore, the impact of various parameters such as number of receiver antennas M , user pairing, imperfect successive interference cancellation and target rate of users γ th , on OP are examined. From the analytical and simulation results it is evident that the proposed system outperforms the C-OMA system.