Performance analysis of secondary throughput in non-time-slotted full duplex cognitive radio networks

Abstract

Through the development of self-interference cancellation technique, recent studies have proposed full duplex cognitive radio newtorks that the secondary users communicate by full duplex with their respective transceiver. In full duplex cognitive radio networks, total throughput of secondary user networks can be improved by transmitting and receiving the data, or transmitting the data and sensing the existence of the primary user. In this paper, we consider the cooeprative spectrum sensing in the non-time-slotted full duplex cognitive radio networks and propose a new scheme to improve the average throughput. In the non-time-slotted cognitive radio networks, the primary user can change its activity during the transmission duration in contrast with the time-slotted cognitive radio networks. We analytically derive the collision probability and the outage probability for the two operation strategies of the secondary user under the cooperative spectrum sensing in non-time-slotted full duplex cognitive radio networks. We also analytically derive the collision probability and the outage probability for the proposed scheme in non-time-slotted full duplex cognitive radio networks. We then turn to determine the optimum decision threshold for the energy detector at each secondary user to maximize the average throughput subject to a constraint on the outage probability of primary user. In numerical results, we demonstrate and analyze the impact of cooperative spectrum sensing and proposed scheme in the non-time-slotted full duplex cognitive radio networks.