Power Control in Cognitive Radio Networks: How to Cross a Multi-Lane Highway

Abstract--We consider power control in cognitive radio networks where secondary users identify and exploit instantaneous and local spectrum opportunities without causing unacceptable interference to primary users. We qualitatively characterize the impacts of the transmission power of secondary users on the occurrence of spectrum opportunities and the reliability of opportunity detection. Based on a Poisson model of the primary network, we quantify these impacts by showing that (i) the probability of spectrum opportunity decreases exponentially with the transmission power of secondary users, where the exponential decay constant is given by the traffic load of primary users; (ii) reliable opportunity detection is achieved in the two extreme regimes in terms of the ratio between the transmission power of secondary users and that of primary users. Such analytical characterizations allow us to study power control for optimal transport throughput under constraints on the interference to prim...

• Type: Journal
• Year: 2008
• Where: CORR
• Authors: Wei Ren, Qing Zhao, Ananthram Swami
• Keywords: CORR 2008, Education, Primary Users, Secondary Users, Spectrum Opportunities