An Efficient Power Control Algorithm for Supporting Cognitive Communications in Shared Spectrum Areas

The concept of Cognitive Radio (CR) is meant to be utilised by both licensed and license-exempt users that coexist in a shared spectrum area whenever they need to avoid causing unaffordable interference to each other by following some rules. In fact, primary users should be protected by any licenseexempt transmission. To this end, power control is a pivotal mechanism to be used for interference management in these scenarios. Especially, transmit power control is a vehicle to mitigate interference, in presence of CR technology, when primary receivers are attempting to reach a desired Signal-to Interference Noise Ratio (SINR) level. In this work we assume that a CR network relies on the same spectrum area with a primary network. Our scope is to measure the introduced interference level caused by the CR transmitter and to properly modify its power to allow a legacy user to reach a required SINR according to location of the primary user in presence of interference. A series of results are presented to prove the efficiency of our proposed scheme.