Fluctuation Noise in Pulse-Height Multiplex Radio Links

The choice of a method of multiplex synthesis and analysis will depend on (1) the distortion and noise characteristics of the link connecting the synthesizer and analyzer, and (2) the type of intelligence and tolerable distortion and noise in each channel. Among the various methods of multiplexing adaptable to transmission over radio links is the pulse-height or commutation method. The question of interchannel cross talk has already been solved quantatatively for this multiplex method, and it is the purpose of this paper to solve the associated problem of channel fluctuation noise in a precise manner. Expressions are obtained for the channel fluctuation noise of pulse-height multiplex systems used over f.m. and a.m. radio links. A comparison shows the f.m. channel fluctuation-noise improvement to be 4.15 times the deviation ratio, in contrast to the familiar √3 the deviation ratio for single-channel radio links.