Spectral efficiency of cognitive radio networks under interference constraint and QoS guarantees

Spectrum Underlay Cognitive radio network model. [Display omitted] ► We study the spectral efficiency of a spectrum underlay cognitive radio network. ► We assume interference power constraint at the secondary network. ► We guarantee quality of service (QoS) for the secondary network. ► Our study relies on a cross-layer design technique. ► The results show the impact of the imposed constraint and the QoS guarantees. We study the problem of maximizing spectral efficiency of cognitive radio network deployments subject to an interference constraint and under specific quality of service (QoS) guarantees. The interference constraint corresponds to the upper limit of the received power that can be tolerated at the licensed users’ due to transmissions from unlicensed users. The QoS guarantees stem from the requirements imposed by the applications running at the users’ terminals. A cross-layer design is adopted that maps the user’s requirements into delay related QoS guarantees at the data link layer and error probability QoS guarantees at the physical layer. The obtained numerical results provide important insights regarding the impact of the considered constraint and guarantees on the achievable spectral efficiency of cognitive radio networks.