Throughput-efficient Joint Coalition Formation and Bandwidth Allocation in Cognitive Radio Networks

In this paper we consider the problem of joint coalition formation and bandwidth allocation in cognitive radio networks. We assume that the secondary links will be partitioned into disjoint coalitions, by which the available spectrum will be reused. On the other hand, we assume that the members of each coalition will transmit over orthogonal sub-bands with the available spectrum being optimally allocated among them. We formulate the problem as a coordinated coalition formation game where the optimization is held at a secondary coordinator (SC) that has all the required channel information. Given these assumptions, we use a closed form expression of the optimal bandwidth allocation for any given network partition, and we propose an algorithm to reach a Nash-stable partition (coalition structure), with the objective of maximizing the network throughput. Performance analysis shows that the proposed coalition formation algorithm with optimal bandwidth allocation provides a substantial gain in the network throughput over existing coalition formation techniques as well as the simple cases of singleton and grand coalition.