Baseband video/audio/data transceiver

Abstract

The BASEBAND VIDEO/AUDIO/DATA TRANSCEIVER invention simultaneously transmits and receives baseband video signals, audio signals, and associated digital data and control signals within a single continuous signal over a single physical transmission line. The device is a single cohesive module, best embodied as an integrated circuit. The audio signals are sampled, and subsequently reconstructed. Audio samples and digital signals are multiplexed, then fed to a multirate elastic buffer. The multiplexed signals are extracted from the elastic buffer coincidentally with the video signal horizontal synchronization pulses and applied to these same pulses, then placed on a channel having a similar transceiver at the other end. The transceiver invention separates the received signals from the transmission line by canceling out its own transmitted signal. The received audio and digital data bursts are culled and reshaped. The video signal horizontal synchronization pulses are simultaneously restored to the received baseband video signal. The culled bursts are fed to a second multirate elastic buffer in synchronism with received video signal horizontal synchronization pulses. The culled multiplexed signals are extracted from the second elastic buffer at a constant reconstruction rate, demultiplexed, and then reconstructed. The transceiver timing and synchronization are controlled by two phase locked loops, one for transmitter timing and one for receiver timing, each with its own clock counting chain. The transmitter loop is locked to the transmitted video signal horizontal synchronization pulses, while the receiver loop is locked to the received video signal horizontal synchronization pulses.