Power Control for Underlay Cognitive Radio Networks with Full - duplex

Radio communication, one of core contents in wireless communication, is facing a great crisis of running out of resource. Unlike other energy crisis which can be solved by using all kinds of alternative energy, the only resource of radio communication is channel, in another word, spectrum. Rather than sticking on trying to achieve the rest one percent of capacity, more and more scholars start to realize that methods reuse the existing available channel such as cognitive radio and full-duplex transmission lead a much brighter future. Both cognitive radio (CR) and full duplex transmissions are effective means to enhance spectrum efficiency and network capacity. In this paper, we investigate the problem of power control in an underlay CR network where the CR nodes are capable of full-duplex (FD) transmissions. The objective is to guarantee the required quality of service (QoS) in the form of a minimum signal-to-interference-plus-noise (SINR) ratio at each CR user and keep the interference to primary users below a prescribed threshold. We design an effective distributed power control scheme that integrates a proportional-integral-derivative (PID) controller and a power constraint mechanism to achieve the above goals. We analyze the stability performance of the proposed scheme and develop a hybrid scheme that can switch between FD and half duplex modes. The proposed schemes are validated with extensive simulations.