Dynamic spectrum access (DSA) is an integral part of cognitive radio technology aiming at efficient management of the available power and bandwidth resources. The present paper deals with cooperative DSA networks, where collaborating terminals adhere to diverse (maximum and minimum) quality-ofservice (QoS) constraints in order to not only effect hierarchies between primary and secondary users but also prevent abusive utilization of the available spectrum. Peer-to-peer networks with co-channel interference are considered in both singleand multi-channel settings. Utilities that are functions of the signal-to-interference-plus-noise ratio (SINR) are employed as QoS metrics. By adjusting their transmit power, users can mitigate the generated interference and also meet the QoS requirements. A novel formulation accounting for heterogeneous QoS requirements is obtained after introducing a suitable relaxation and recasting a constrained sum-utility maximization as a convex optimization problem. The optimality of the relaxation is established under general conditions. Based on this relaxation, an algorithm for optimal power control that is amenable to distributed implementation is developed, and its convergence is established. Numerical tests verify the analytical claims and demonstrate performance gains relative to existing schemes.
Bibliographical noteFunding Information:
This work was supported by the USDoD ARO Grant No. W911NF-05-1-0283; through collaborative participation in the Communications and Networks Consortium sponsored by the U. S. ARL under the CTA Program, Cooperative Agreement DAAD19-01-2-0011; the NSF grants CCF-0830480 and ECCS-0824007; and by the Gov. of C.A. Madrid Grant No. P-TIC-000223-0505. The U. S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation thereon. Part of this paper was presented at the IEEE Int. Conf. Acoustics, Speech, and Signal Processing, Las Vegas, NV, Mar.-Apr. 2008. Digital Object Identifier 10.1109/TCOMM.2010.03.080491
- Cognitive radio
- Distributed algorithms
- Dynamic spectrum access
- Optimization methods
- Power control