A simple method for localization in cognitive radio networks

In this paper, we study and propose an efficient method to accurately estimate the position and the transmit power of a primary user for spatial resource utilization in cognitive radio networks (CRNs). Not similar to conventional methods where positions of at least four secondary users are assumed to be known and then, complex techniques such as least square and constrained optimization algorithms are used, we handle the estimation problem with only three known positions of secondary users. Moreover, we give closed forms for all estimated parameters and study the problem in practical scenarios by considering a received signal threshold at secondary users. Computer simulations show the effectiveness of the proposed method.