Detection performance analysis for SCMA based cooperative spectrum sensing under different fading channels

Sparse code multiple access (SCMA) is a novel code domain non-orthogonal multiple access scheme that enables the overloading of the fifth generation multi-user system. SCMA accommodates massive user connectivity, higher spectrum efficiency, low latency, flexible service multiplexing, etc. Integrating SCMA with cognitive features empowers the exploration of more frequencies under the spectrum scarcity issues. This paper proposes spectrum sensing with SCMA technology with an maximum passing algorithm (MPA) detector for multi-user detection at the receiver side. A novel double threshold based log-likelihood ratio MPA detector has been used for spectrum sensing in cooperative cognitive radio networks for Rayleigh fading, Rician fading and generalized Nakagami fading channel. The analytical detection performance versus signal to noise ratio (SNR) curve has been compared with the simulation results for the corresponding fading channels. The simulation results verify the SCMA-based system model performance in terms of detection probability well matched with analytical results. The paper also includes the comparative study of detection probability vs SNR under Rayleigh, Rician and Nakagami fading channel.