Optimal Congestion Control and Power Control with Outage Constraints in Cognitive Radio Networks

In this paper, we investigate the joint congestion control and power control for cognitive radio networks over fading channels. A cross-layer optimization problem based on the generalized network utility maximization framework is formulated to consider the outage probabilities of both primary and secondary links. After transferring it to a convex one by geometric programming, we employ a dual decomposition method to deduce two maximization sub-problems, and then two effective distributed iterative algorithms at transport layer and physical layer are proposed to achieve the optimal source rates and link transmission power levels. Numerical results show that the proposed algorithm providing outage probability guarantee and energy saving within reasonable convergence time.