Performance analysis of an (m, n) energy detector in fading environment with double threshold

It is known that, energy detector for spectrum sensing in cognitive system is simple in implementation, fast, and standards independent. However, it is known that energy detector suffers from its dependency over the noise level of detected signal. Different techniques have been proposed in order to combat that dependency. Among those techniques: antenna diversity, collaborative sensing, and double threshold schemes. In this paper we propose a technique that uses an m-antenna diversity and n-sensors collaboration (m, n) in order to improve the performance of a double threshold energy detector in fading channel. Close formulas for Receiver Operating Characteristics (ROC) and its complement were used in our analysis. Simulation results in both AWGN and fading channels show an agreement with obtained results in the case of Gaussian channel and confirm the behaviour of double detector on the sense of improving probability of collision at the expense of spectrum utilization.