Performance of Cooperative Spectrum-Sharing Systems with Amplify-and-Forward Relaying

This paper investigates the performance of using cooperative relaying technique in spectrum-sharing cognitive radio (CR) systems while considering constraints on the average received-interference at the primary receivers. Specifically, we consider that the communication between a secondary source and its destination nodes is assisted by an intermediate relay that uses amplify-and-forward (AF) strategy. In this context, we obtain closed-form expressions for the probability density function (PDF) of the received signal-to-noise ratio (SNR) at the secondary destination node for different channel fading distributions, namely, Nakagami and Rayleigh. Then, the end-to-end performance of the proposed cooperative relaying spectrum-sharing system is investigated in terms of the overall achievable capacity and outage probability of the secondary user communication. Finally, simulation results sustaining our theoretical analysis are provided and comparisons illustrating the overall performance of the cooperative spectrum-sharing system are drawn for different propagation conditions.