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The problem of resources allocation in multiple-input multiple-output-orthogonal frequency division multiplexing based cooperative cognitive radio networks is considered, in this paper. The cooperation strategy between the secondary users is decode-and-forward (DF) strategy. In order to obtain an optimal subcarrier pairing, relay selection and power allocation in the system, the dual decomposition technique is recruited. The optimal resource allocation is realized under the individual power constraints in source and relays so that the sum rate is maximized while the interference induced to the primary system is kept below a pre-specified interference temperature limit. Moreover, because of the high computational complexity of the optimal approach, a suboptimal algorithm is further proposed. The jointly allocation of the resources in suboptimal algorithm is carried out taking into account the channel qualities, the DF cooperation strategy, the interference induced to the primary system and the individual power budgets. The performance of the different approaches and the impact of the constraint values and deploying multiple antennas at users are discussed through the numerical simulation results. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In the cognitive radio (CR) networks consisting of selfish users competing for spectrum resources, the social optimum is usually not achieved at the Nash equilibrium (NE) of the power control game, since selfish users are only interested in their own benefit. In this study with the aim of improving the NE efficiency, the authors extend the pricing concept to a multi-channel multiple-in multiple-out (MIMO) CR scenario and propose two iterative algorithms for power control and channel allocation in such systems. Specially, the authors consider both linear and non-linear pricing methods and derive the optimal pricing factor for both scenarios and prove the existence and uniqueness of the NE. Simulation results prove the outstanding performance of the proposed MIMO cognitive system considering price-based power control over the non-price-based MIMO cognitive systems. [ABSTRACT FROM AUTHOR]