Methods and apparatus for simultaneously communicating voice and data in an analog cordless telephone system

摘要

A method of simultaneously communicating voice and data on the same channel in an analog cordless telephone system involves generating an analog signal from an audible voice signal during a cordless telephone call; generating a frequency shift keying (FSK) signal from digital data having a nominal frequency of about 20 KHz; summing the analog signal and the FSK signal to produce a composite analog and digital signal; modulating a radio frequency (RF) carrier with the composite analog and digital signal to produce a modulated RF carrier; and transmitting the modulated RF carrier. On the receiving end, the method involves receiving the modulated RF carrier during the call; demodulating the modulated RF carrier to reproduce the composite analog and digital signal; bandpass filtering the composite analog and digital signal to separate the analog signal and the FSK signal from one another; reproducing the audible voice signal from the analog signal; and detecting the digital data from the FSK signal and processing the digital data for display and control.