Exact Ergodic Capacity Analysis for Cognitive Underlay Amplify-and-Forward Relay Networks over Rayleigh Fading Channels

Vo Nguyen Quoc Bao, Vu Van San


In this paper, we propose a novel derivation approach to obtain the exact closed form expression of ergodic capacity for cognitive underlay amplify-and-forward (AF) relay networks over Rayleigh fading channels. Simulation results are performed to verify the analysis results. Numerical results are provided to compare the system performance of cognitive underlay amplify-and-forward relay networks under both cases of AF and decode-and-forward (DF) confirming that the system with DF provides better performance as compared with that with AF.

DOI: 10.32913/rd-ict.vol3.no14.563


Ergodic capacity, Rayleigh fading channels, cognitive radio, underlay relay networks, amplify-and-forward, decode-and-forward.


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