Signal processing device, CATV head end, and CATV system

摘要

PROBLEM TO BE SOLVED: To provide a signal processing device capable of processing signals with increased quality, a CATV head end, and a CATV system.SOLUTION: A signal processing device 100 comprises: a down-converter 2 which converts an input high-frequency signal to an intermediate frequency signal; a local oscillation unit 11 which supplies a local oscillation frequency signal to the down-converter 2; an intermediate frequency processing unit 3 including a bandpass filter 3a which selectively transmits a prescribed band of the intermediate frequency signal; an A/D conversion unit 4 which converts the intermediate frequency signal that has transmitted through the bandpass filter 3a from analog to digital; an orthogonal demodulation unit 5 which generates a baseband signal from the intermediate frequency signal after the A/D conversion; a digital filter 6 which performs digital signal processing for selectively transmitting a prescribed band of the baseband signal; and an orthogonal modulation D/A conversion unit 8 which converts the baseband signal that has transmitted through the digital filter 6 to a high-frequency signal from digital to analog.