Characteristics of small-area signal fading on mobile circuits in the 150 MHz band

Abstract

Transmission on mobile radio circuits is often affected by standlng-wave breakup" resulting from spatial variations in rf signal amplitude, which to the moving mobile unit appear as rapid fades. Measurements made in the 150 mHz band confirm previous reports that within any small area such signal variations tend to follow the Rayleigh distribution. Statistical distributions have also been determined for the depths and widths of fades, in several different environments where fading was severe; rural, suburban and urban situations were found to produce rather similar results in-these respects. Some information is also given on the relation between median signal and circuit quality for speech, under fading conditions.