Signal processing apparatus, the receiving device, catv head-end and catv system

摘要

PROBLEM TO BE SOLVED: To appropriately switch reception systems.SOLUTION: A signal processor includes: an active system part having a first down converter for converting an inputted high frequency signal into an intermediate frequency signal, a first IF part for extracting a signal of a desired channel from the intermediate frequency signal, and a first detector part for outputting a first detection voltage, provided after the first IF part; a reserved system part having a second down converter for converting an inputted high frequency signal into an intermediate frequency signal, a second IF part for extracting a signal of the desired channel from the intermediate frequency signal, and a second detector part for outputting a second detection voltage, provided after the second IF part; a determination part for determining whether to output a signal from the active system part or a signal from the reserved system part, based on the first detection voltage and the second detection voltage; and a switching part for switching a path to either the active system part or the reserved system part according to the determination.