Simulcast transmission system having automtic synchronization

Abstract

An improved simulcast transmission system having automatic synchronization is disclosed which utilizes a signal from any one of a number of readily available master timing sources to maintain a constant, uniform time delay to a multiplicity of transmitters even though the time delay corresponding to an included individual interconnect link is susceptible to variation. This simulcast system includes a central controller for controlling, via an interconnect link, the operation of each transmitter located at a plurality of base station sites. This central controller includes a master timing signal receiver and periodically outputs a resynchronization command via the interconnect link to the base stations. Each interconnect link may consist of a phone line or other radio link which exhibits a relatively fixed, but unstable, delay. Each base station includes at least a transmitter and an adaptive-delay device which operates as a remotely-adjustable delay network upon receipt of a resync signal from the central controller to readjust and automatically maintain a uniform amount of time delay to each transmitter in the base stations. A master timing signal receiver such as a suitable radio navigation receiver is coupled to a suitable fixed delay network and provides the reference sync signal for each remotely-sited base station throughout the designated geographical area. This simulcast system is therefore cable to compensate for varying amounts of delay caused by utilizing alternate links which may be necessary to maintain system reliability while overcoming inclement weather, interference, or other equipment difficulties.

Dependencies are inferred from the claim text.