  In this paper, a novel framework for normative modeling of the spectrum
sensing and sharing problem in cognitive radios (CRs) as a transferable utility
(TU) cooperative game is proposed. Secondary users (SUs) jointly sense the
spectrum and cooperatively detect the primary user (PU) activity for
identifying and accessing unoccupied spectrum bands. The games are designed to
be balanced and super-additive so that resource allocation is possible and
provides SUs with an incentive to cooperate and form the grand coalition. The
characteristic function of the game is derived based on the worths of SUs,
calculated according to the amount of work done for the coalition in terms of
reduction in uncertainty about PU activity. According to her worth in the
coalition, each SU gets a pay-off that is computed using various one-point
solutions such as Shapley value, \tau-value and Nucleolus. Depending upon their
data rate requirements for transmission, SUs use the earned pay-off to bid for
idle channels through a socially optimal Vickrey-Clarke-Groves (VCG) auction
mechanism. Simulation results show that, in comparison with other resource
allocation models, the proposed cooperative game-theoretic model provides the
best balance between fairness, cooperation and performance in terms of data
rates achieved by each SU.
