Dirtortion AND Crosstalk Caused by Multipath Propagation in Frequency-Modulation Sound Broadcasting

The characteristics of multipath distortion in FM sound broadcasting were determined through computer analysis and subjective listening tests. Stereophonic multipath distortion is found to be far greater than monophonic multipath distortion, especially for long delay times. Crosstalk into stereophonic main-program reception due to multipath propagation from the SCA (Subsidiary Communications Authorization) using a 67-kHz subcarrier was also analyzed and multiplexing of the SCA is found to have a potential for causing severe crosstalk trouble. The DU ratios required to suppress the distortion and the crosstalk are provided.