Signal-To-Noise Ratio Out of an Ideal FM Detector for SSB FM Plus Gaussian Noise at the Input

The signal-to-noise ratio (SNR) at the output of an ideal FM detector is determined as a function of the modulation index for the case of an SSB-FM signal plus narrow-band Gaussian noise at the input, where the input SNR is large. The modulation is assumed to be sinusoidal, and the noise is taken to be flat over the intermediate frequency band.