Bit error rate and outage analysis of an interference cancellation technique for cooperative spectrum sharing cognitive radio systems

Abstract

In this study, an overlay spectrum sharing scheme has been proposed for a cognitive radio system. To achieve the desired quality of service for the licenced (i.e. primary) system and spectrum access for unlicenced (i.e. secondary) system, a three-phase cooperative decode and forward relaying is used. Furthermore, space–time block coding is used in order to cancel the interference at primary as well as secondary receiver. It has been shown that the proposed scheme helps in achieving diversity gain of three and two for primary and secondary systems, respectively. The performance of both primary and cognitive (secondary) system is appraised by deriving closed-form expression for bit error rate and outage probability. The theoretical and simulation results validate that the proposed scheme improves the performance of both systems as compared with the earlier proposed schemes.