A centralized cooperative power control algorithm for cognitive radio networks

In cognitive radio networks, coexistence of primary users (licensed users) and secondary users needs a power control algorithm employed by secondary users to avoid harmful interference and guarantee acceptable minimum signal-to-interference-plus-noise ratio (SINR) to the primary users. In this paper we present a centralized cooperative power control algorithm for cognitive radio networks in which a Central Base Station (CBS) collects secondary users' side-information and finds maximum number of secondary users who can achieve their target-SINRs while their total interference caused to primary users is kept bellow a given threshold. In our proposed algorithm each secondary user upon detecting a primary receiver estimates its location (distance and direction) with respect to the detected primary receivers and sends this side-information to the CBS. Assuming that, CBS knows locations of secondary users; CBS employ our proposed power control algorithm to find as many as possible secondary users who can coexist with primary users. Our simulation results show that complexity of our proposed algorithm is very low as compared to the exhaustive-search and it results in maximum number of supported secondary users (those who can reach their target-SINRs) keeping their total interference to primary users bellow a given threshold.