Research On Distributed Power Control In Cognitive Radio Network

With the rapid development of communication technology, wireless resources become more congested. As one of the most effective measures to solve the problem of wireless resources scarcity, Cognitive Radio(CR) has attracted much more researchers’ attention. Due to the interference from Secondary Users(SUs) to Primary User(PU) must be limited strictly and SUs should communicate normally, power control between SUs is necessary.In Cognitive Radio networks(CRNS), the competition relationship between SUs makes researchers use game theory to solve the power control problem. In this paper, we assume that PU and multiple SUs coexist in the same band at the same time. Taking into consideration that both PU and SUs can communicate normally, a distributed power control algorithm that aims at the whole energy efficiency of the cognitive networks is studied. Considering low energy efficiency in most of existing algorithms, we propose a distributed multi-Leader Stackelberg(DMS) algorithm on the basis of non-cooperative power control game(NPG) algorithm. The proposed algorithm divides all the SUs into two parts and conducts different strategies aimming at reducing the overall interference until the algorithm converges.Compared with others in which SUs maximize their own utilities selfishly, SUs in this paper make up for the loss of the whole energy efficiency in CRNs by combining cooperation with non-cooperation to implement power allocation. Besides, the simple utility function and power reduction strategy(PRS) makes the algorithm easy to implement. Finally, the simulation results verify the proposed power control algorithm improves the Qo S of PU and the total energy efficiency of the cognitive network, reduces the transmission power of SUs and facilitates the efficient utilization of wireless resources.