Signal-to-noise ratios in strong-carrier FM systems

Signal-to-noise ratios are derived for an FM (frequency modulated) system in which the r-f (radio-frequency) carrier is strong compared with the noise. The results are derived in a simple way without making use of high-order probability density functions. General formulas are derived for determining the signal-to-noise ratio with periodic modulation or with pulse modulation, and numerical results are given for the special case of a flat symmetrical r-f passband. The effect of a mistuned frequency detector is also taken into account.