Patent ID: 7813619

Claim:
A digital signal receiving system comprising: a digital signal receiving device which receives a digital communication signal, has a function of generating a clock signal based on PCR data included in the communication signal, and a function of transmitting a stream signal in the form of a plurality of packets, as well as the clock signal, the stream signal including the communication signal; and a host device which receives the stream signal and the clock signal from the digital signal receiving device via an interface section, the digital signal receiving device including: a recipient STC counter which counts the number of clocks of the clock signal and outputs the counter value as recipient STC data; a variation detector which calculates a difference between the recipient STC data and the PCR data as difference data, and detects a variation in frequency of the clock signal that exceeds a predetermined value based on the difference data; and a variation processor which sends, to the host device, variation information data obtained based on the recipient STC data and the PCR data, and sets the PCR data in the recipient STC counter if the variation detector detects the variation in frequency that exceeds the predetermined value, and the host device including: a host STC counter which counts the number of clocks of the clock signal sent from the digital signal receiving device, and outputs the counter value as host STC data; and an STC correcting unit which calculates correction data based on the host STC data and the variation information data if the variation detector detects the variation in frequency that exceeds the predetermined value, and sets the correction data in the host STC counter so as to coincide the counter value set in the recipient STC counter with the counter value set in the host STC counter.