Throughput maximisation by optimising detection thresholds in full-duplex cognitive radio networks

Herein the authors consider throughput maximisation for a secondary user (SU) in a full-duplex cognitive radio network (FD-CRN) when the SU has two separate antennas and a self-interference suppression capability. In the FD-CRN, the SU can simultaneously sense the spectrum throughout the whole time slot and transmit data. They propose algorithms based on brute-force search and particle swarm optimisation methods to help the SU achieve optimal detection thresholds for spectrum sensing in two different FD-CRN scenarios. In the first scenario, the SU individually performs spectrum sensing, whereas in the second scenario the SU's sensing results are improved by means of cooperative spectrum sensing. Theoretical and simulation results herein show that, for certain values of the system parameters in the above two scenarios, the system under consideration provides much higher throughput than previously proposed systems in conditions of high-transmission power or low signal-to-noise ratio of the primary signal.