Analysis of the output of FM correlation systems

By the term "FM correlation system," we mean the analog correlation system that consists of two channels, each containing an FM detector. Expressions are derived for the output of the FM correlation system for the following cases. Each channel input to be correlated is a conventional FM signal plus Gaussian noise; and each input is an amplitude-limited or a nonlimited narrow-band Gaussian random signal plus Gaussian noise. The effect of the input carrier-to-noise power ratios is made clear. The features of the FM correlation system are shown in comparison with a conventional correlation system. In addition, a detailed analysis of the effect of the envelopes of the narrow-band Gaussian random signals on the output is presented.