where B_e is the required bandwidth

where B_e is the required bandwidth, ∆f_pp is the peak-to-peak frequency deviation of the modulator, f_v is the highest video frequency, and w is a weighting factor used to account for the nonuniform response of the eye pattern to white noise in the video bandwidth. The total S/N improvement depends on the system design, but is generally in the range 36-44 dB.11,22 The reduced C/N requirements thus make an FM system much less susceptible to laser and receiver noises than an AM system.