AM-PSK system for broadcasting a composite analog and digital signal using adaptive M-ary PSK modulation

摘要

A radio-frequency broadcasting system and method for simultaneously broadcasting analog and digital signals in a standard AM broadcasting channel wherein the system includes: a transmitter for providing, and broadcasting, a composite signal containing an adaptively- modulated phase- shift-keyed digital signal with analog programming material modulated thereon; and a receiver for detecting the composite signal, extracting the analog audio signal and digital audio, or data, therefrom, and playing back the received audio programming. The adaptively-modulated phase-shift-keyed digital signal is responsive to the transmitted signal, dynamically increasing the digital data transmission rate as the transmitted signal power increases. Symbol states are generally arranged around concentric arcs, and adjacent symbol states are generally equidistant.