Range-based Primary User Localization in Cognitive Radio Networks

In cognitive radio networks (CRNs), information regarding the positions of the primary users (PUs) is crucial as it may be helpful for improving the spectrum utilization and to avoid harmful interference. Existing Range-based methods require three or more than three known secondary users (SUs) to estimate primary user location and hence have the limitation that they cannot work if there are only two known secondary users available in the system. Also the existing methods cannot work if the precondition for applying Trilateration method is not satisfied (i.e. no common intersection point between the circles drawn for the secondary users). In this article we present Range based primary user localization technique to find out the location of PUs along with their transmit power. The proposed technique relies on the information collected from only two SUs to carry out the localization process unlike the existing techniques.