A radar detector using quantized envelope samples

The detection of a sequence of echo pulses with random carrier phase is an important problem in radar. It is well known that, to a first approximation, the optimum receiver is a quadratic detector for small signal-to-noise ratios and is a linear detector for large signal-to-noise ratios. In this paper, a detector based on scaling and rounding envelope samples into digital words of only a few bits is presented and analyzed. This detector is essentially a generalization of a suboptimum detector known as a binary detector which performs postdetection integration by digital counting and is particularly useful in automatic detection systems. The asymptotic relative efficiencies of this detector relative to the quadratic detector and the linear detector are obtained. Also, nonasymptotic performance comparisons based on relative efficiency and on probability of detection are made. It is shown that this detector is more efficient than the other two detectors in most signal-to-noise ratio ranges. In addition, this detector is applicable when the noise environment is somewhat different from Gaussian.