METHOD AND APPARATUS FOR ADAPTIVE POWER ADJUSTMENT OF MIXED MODULATION RADIO TRANSMISSION

摘要

Audio input (154) is transmitted via frequency modulation transmitter (156) and digital data (162) is simultaneously transmitted from a second transmitter (162). Both transmissions are received by a common receiver (158). Prior to transmission, the audio input is processed by a psychoacoustic processor (164) which controls an attenuator (166). The digital data is modified by the attenuator prior to transmission to ensure that it does not exceed a global masking threshold of the audio signal. This results in reducing noise introduced by the digital data at transmission to a level at the receiver which cannot be perceived by the human ear.