초록 ▼

A simulcast transmitter apparatus having automatic synchronization capability is disclosed which utilizes a signal readily available from any one of a number of available master timing sources to maintain a constant, uniform time delay to the transmitter via its interconnect link, even though the ti

A simulcast transmitter apparatus having automatic synchronization capability is disclosed which utilizes a signal readily available from any one of a number of available master timing sources to maintain a constant, uniform time delay to the transmitter via its interconnect link, even though the time delay corresponding to this interconnect link is susceptible to variation. 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 a 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 transmitter is therefore able to be compensated 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.

대표청구항 ▼

In a plurality of base stations, each having a transmitter connected to a central controller via an interconnect link having an associated time delay and forming one branch of a simulcast transmission system for transmitting message signals in a synchronized first mode, apparatus for providing autom

In a plurality of base stations, each having a transmitter connected to a central controller via an interconnect link having an associated time delay and forming one branch of a simulcast transmission system for transmitting message signals in a synchronized first mode, apparatus for providing automatic synchronization capability, the apparatus comprising in combination: adaptive delay means, inserted between said interconnect link and said transmitter, having a first input electrically connected to said interconnect link and a second input for utilizing a reference sync signal; and master timing signal receiving means electrically connected to said second input of said adaptive delay means for providing said reference sync signal thereto, said adaptive delay means having a first and a second mode of operation, with said second mode activated upon detecting a re-sync command from said central controller at said first input and utilizing said reference sync signal at said second input for varying an adjustable time delay therein in opposite fashion to said associated delay, for re-adjusting, during said second mode and automatically maintaining during said first mode, a constant total delay from said central controller to each of said transmitters, for sending message signals from said base stations in precise time synchronization.