Resource allocation for outage probability minimisation in cognitive radio multicast networks

In this paper, we consider a downlink secondary cognitive radio multicast network that consists of a cognitive base station and a set of secondary multicast groups sharing spectrum with a primary network. To protect the transmissions of the primary network, an interference power constraint is applied to restrict the transmit power of the cognitive base station. The problem of joint channel and power allocation for the cognitive radio multicast network is studied. The objective is to minimise the weighted aggregate outage probability for a given target rate for the cognitive radio multicast network. Specifically, two types of outage probabilities, namely, group outage probability and individual outage probability, are considered. For each type of outage probability, the optimal joint channel and power allocation algorithm is proposed based on Lagrange dual optimisation. Simulation results are illustrated to verify the effectiveness of the proposed algorithms. It is shown that the proposed algorithms significantly improve the performance of the cognitive radio multicast network in terms of outage probability. Copyright © 2014 John Wiley & Sons, Ltd.