An Improved Power Control Strategy for Cognitive Radio Networks with Imperfect Channel Estimation

Power control of secondary user is an important issue for cognitive radio systems to protect the transmission of primary users. There are several ways to protect the primary user under the accurate estimation of the channels. In this paper, we focus on the protection of primary user under the imperfect channel estimation. We first gives the mathematical expressions of the outage probability of the primary link and the capacity of the secondary user under imperfect channel estimation. In order to alleviate the impact of channel estimation error and to enhance the robustness of the primary link, an improved power control strategy is then proposed. We also study the tradeoff between the primary user protection and the capacity of the secondary user via computer simulations.