Distortion produced by band limitation of an FM wave

Abstract

The bandwidth required to transmit an FM wave is related to how much distortion is allowed in the signal. Here expressions are developed for the distortion (interchannel interference) produced when an FDM-FM wave passes through an ideal filter. The signal is represented by a flat (PM) band of Gaussian noise. The formulas obtained hold only for small rms frequency deviation, but fortunately this is an important case in microwave communication systems. The theoretical expressions agree well with Monte Carlo results published recently by Anuff and Liou.