C-NOMA system with adaptive SC-SBMRC diversity receiver over fading channels

Cooperative Non Orthogonal Multiple Access (C-NOMA) has gained significant recent interest as a highly promising option in providing quality of service to the users. It is a key component of upcoming communication systems. The primary objective of our work is to improve the downlink CNOMA system’s performance with a single ground station and two users by considering perfect channel. The fading effect causes a decrease in system performance. To improve system performance, the existing Selection Combining (SC) and Maximal Ratio Combining (MRC) diversity approaches are inadequate. In order to enhance performance, the proposed Adaptive Selection Combining and Selective Branch Maximal Ratio Combining diversity technique (SC-SBMRC) is used in downlink C-NOMA system at the receiver for fusion. Bit Error Rate and Outage Probability metrics are used to assess C-NOMA system’s performance with different fading channels. The proposed system taken in to consideration of Nakagami-m and Rayleigh generalized fading channels with ‘$\alpha -\eta -\mu$’ distribution by incorporating three essential fading parameters. The simulation experiments were carried out by using MATLAB Software. From the results it is observed that the Bit Error Rate is reduced from $4.8\times 10^{-1}$ to $3.0\times 10^{-3}$and also the Outage Probability enhanced from $9.6\times 10^{-2}$ to $9.4\times 10^{-3}$. Based on the numerical findings, the Cooperative Non-Orthogonal Multiple Access system with Adaptive SC-SBMRC diversity technique shows superior performance as compared to conventional C-NOMA system in providing quality of service to distant user.