Effects of Video Bandwidth on the Performance of a Square Law Detector with Gaussian IF and Video Filters.

摘要

The effects of Gaussian-shaped IF and video filters on the performance of a square-law detector employing post-detection integration are analyzed. The number of additional noise-only samples that are integrated due to a finite video bandwidth is determined. Emerson's method is used to obtain an expression for the cumulants of the output probability density function. These cumulants are used in Edgeworth's asymptotic series expansion of the density functions. By integrating these density functions, the receiver operating characteristics are determined for various ratios of IF bandwidth to video bandwidth. A collapsing ratio which takes into account the Gaussian shape of the filters is formulated and compared against Barton's approximate formula for the collapsing ratio. For typical video bandwidths, Barton's approximate formula is found to overestimate the collapsing loss by an amount less than 0.5 db. (Author)