Joint Access-Selection and Power Allocation for Spectrum Sharing Cognitive Radio Networks

Dynamic spectrum access via active spectrum sharing has been considered as a promising approach to improve the spectrum utilization for future wireless systems. In this paper, based on our recent study on the optimal transmit-power allocation for an active spectrum sharing system comprised of single primary-user (PU) and multiple secondary-users (SUs) [7], we move a further step to investigate a more challenging scenario comprised of multiple PUs and multiple SUs. Specifically, we formulate a joint SU-selection and power allocation problem, in which the PUs properly select different groups of SUs to share channels with and the PUs and SUs then determine the proper transmit-powers. We aim at maximizing a system reward for serving the SUs' traffic while trading off the PUs' additional power consumptions to guarantee their required quality of service (QoS). We exploit the layered structure of the joint optimization problem and propose an efficient algorithm to solve it. Numerical results are provided to validate performances of the proposed algorithm and show advantages of performing the joint SU-selection and power allocation in active spectrum sharing.