Spectrum sensing error optimisation in cognitive radio networks

In this paper, we analyse the spectrum sensing error in cognitive radio networks that use energy detection to determine the presence of primary users. We present a theoretical framework to show the existence of a minimum in the spectrum sensing error for an optimally selected energy detection threshold. We apply our analysis to both cooperative and non-cooperative sensing network scenarios. In the cooperative configuration, we present upper and lower bounds for the optimum energy detection threshold and in the non-cooperative configuration, we present a closed form expression for the optimum energy detection threshold. We also investigate the sensitivity of the sensing error to the detection threshold at different PU signal levels. We validate our analysis against empirical data obtained from a cognitive radio testbed based on the Universal Software Radio Peripheral hardware platform.