Zero-Crossing Principle for Detecting Narrow-Band Signals

This paper describes a zero-crossing principle for detecting weak narrow-band signals immersed in Gaussian noise. The principle is simple to implement and leads to a zero-crossing detector, comparable in performance to a square-law detector. The zero-crossing principle has many of the properties associated with the incoherent phase principle of signal detection. Unlike the square-law detector, the zero-crossing detector is relatively insensitive to system gain fluctuations. Probability of false alarm and probability of error are presented for both the square-law detector and the zero-crossing detector. An application of the zero-crossing principle to the problem of incoherent detection of a stationary radar target in clutter is discussed.