Application of Compandors to FM Radio Systems with Frequency Division Multiplexing

Compandors are used to improve the intelligibility of speech transmission circuits by increasing the signal-to-noise ratio. Originally developed in the early 1930's for use with transoceanic radio circuits, they have since been applied to some extent on long distance telephone circuits, usually of the carrier-derived type. Within the past few years new telephone carrier systems have been developed which include a compandor as an integral part of the equipment for each speech channel.