Power and Admission Control for UWB Cognitive Radio Networks

In this paper, we consider the power and admission control for ultra-wideband (UWB) cognitive radio networks, which are important to provide secondary users guaranteed quality of service while not causing severe interference to primary users. A power control algorithm to maximize the minimal data rate of all admitted secondary users is developed by solving a quasi-convex optimization problem. An admission control algorithm is also proposed to reject secondary users, which induce infeasible power control or low sum data rate, by a new criterion - the channel gain ratio. The channel gains used in the proposed algorithms are estimated by exploiting the ranging capability of UWB radios. The estimation error due to unpredicted channel shadowing is coped with the interference hole and the signal-to-interference-noise ratio margin. Finally, the performance of the presented power and admission control strategy is examined through simulations.