Energy detector performance in a noise fluctuating channel

The authors address the energy detection performance of a detector, or more specifically, the determination of the required signal-to-noise ratio (P_s/P_n) for given probabilities of detection (P_d) and probabilities of false-alarm (P_fa) in a noise fluctuating channel. A theoretical model for evaluating energy detection performance is presented. It is shown that the classical model for analytically predicting the detection performance of an energy detector is suitable when the channel noise level is assumed Gaussian distributed. However, for a channel in which the noise fluctuates, the model proposed by the authors is more applicable. In this case, to hold the probability of false alarm constant, the average detection threshold must be set at a higher level than if the noise were assumed Gaussian. It is concluded that in a channel, such as the HF channel, where the fluctuating noise level approximates a lognormal distribution, an increase in integration time could improve P_d up to a limit. This limit is a function of P_s/P _n and the noise characteristics