Performance analysis of a relay-aided cognitive radio network with multiple secondary links

Abstract

In this paper, we investigate a cooperative D2D communication in cognitive radio (CR) networks, which is composed of two secondary links, one primary link, and a relay network. In cases where data transmission is not performed directly, the source devices can communicate with their destinations via the relay network, which consists of some idle secondary devices. We propose a clustering relay selection (RS) method to enable simultaneous transmission of primary and secondary sources. The proposed RS classifies the relay devices into two clusters and assigns one cluster to the primary link and another to the secondary links. Furthermore, an interference management approach is proposed to improve the system performance. By jointly employing the proposed RS and a cooperative beamforming (CBF) method in each cluster, the investigated approach can maximize the received SINR at the destinations while maintaining the interference plus noise power below a predefined threshold. To investigate the performance, we optimize the proposed RS and CBF vectors by solving a convex semidefinite problem using the bisection search algorithm. Simulation results are provided to show the efficiency of the investigated strategy.