OFFSET BEAT ELIMINATION DEVICE, TELEVISION BROADCAST SIGNAL TRANSMITTER, AND TELEVISION BROADCAST TRANSMISSION/RECEPTION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an offset beat elimination device and a television broadcast signal transmitter optimum for constructing a television broadcast reception system having a beat canceling function. SOLUTION: A head end device 20 is provided with a beat canceler 30 which eliminates interference wave components to generate offset beat from a television broadcast signal of a prescribed channel. In the beat canceler 30, a channel selection demodulation part 32 consisting of a general purpose tuner module selects a station of television broadcast of the prescribed channel and generates a video IF (intermediate frequency) and sound IF. A video signal processing part 34 generates an I/Q signal by performing quadrature detection of the video IF the phase of which is delayed by 180 degrees by using video carrier waves reproduced from the video IF. Furthermore, the interference wave components are generated by performing digital processing to a Q signal and the video signal is generated by eliminating the interference wave components from an I signal. A re-modulation part 38 generates the television broadcast signal of the prescribed channel from the generated video signal and sound IF. COPYRIGHT: (C)2004,JPO&NCIPI