Minimum-Bandwidth Multiplex Radioteleprinter System
R. Tottingham · IRE Transactions on Communications Systems · 1971
A new data system uses AM broadcast signals to carry teleprinter signals. Useable at medium or shortwave frequencies, the multiplex technique provides point-to-point or broadcast teleprinter service utilizing existing transmitters and antennas. A minimum-bandwidth PM subcarrier is used to phase modulate the broadcast carrier wave without disturbing operation of either the broadcast transmitter or receiver.