Interference-based optimal power-efficient access scheme for cognitive radio networks

In this paper, we propose a new optimization-based access strategy of multi-packet reception (MPR) channel for multiple secondary users (SUs) accessing the primary user (PU) spectrum. We devise an analytical model that realizes the multi-packet access strategy of the SUs. All the network receiving nodes have MPR capability. We aim at maximizing the throughput of the individual SUs subject to the PU´s queue stability. Moreover, we are interested in providing an energy-efficient cognitive scheme. Therefore, we include energy constraints on the PU and SU average transmitted energy to the optimization problem. Each SU accesses the medium with certain probability that depends on the PU´s activity, i.e., active or inactive. The numerical results show the advantage in terms of SU throughput of the proposed scheme over the conventional access scheme, where the SUs access the channel randomly with fixed power when the PU is sensed to be idle.