A Two-Phase Channel and Power Allocation Scheme for Cognitive Radio Networks

We consider a cognitive radio network in which a set of base stations make opportunistic unlicensed spectrum access to transmit data to their subscribers. As the spectrum of interest is licensed to another (primary) network, power and channel allocation must be carried out within the cognitive radio network so that no excessive interference is caused to any primary user. For such a cognitive network, we propose a two-phase channel/power allocation scheme that improves the system throughput, defined as the total number of subscribers that can be simultaneously served. In the first phase of our scheme, channels and power are allocated to base stations with the aim of maximizing their total coverage while keeping the interference caused to each primary user below a predefined threshold. In the second phase, each base station allocates channels to their active subscribers based on a maximal bipartite matching algorithm. Numerical results show that our proposed resource allocation scheme yields significant improvement in the system throughput