| 摘要 |
<P>PROBLEM TO BE SOLVED: To calculate a much more accurate C/N ratio in consideration of the influences of digital interference wave, analog interference wave and apparatus deterioration when evaluating the quality of a terrestrial digital broadcast line on the basis of the C/N ratio of a terrestrial digital broadcast signal. <P>SOLUTION: Each of D/U ratio adding sections 16-2 to 16-N of arithmetic units 10-2 to 10-N adds D/U ratios of analog interference waves at relay stations from the stage of the adding section's own to the pre-stage, and each of equivalent C/N ratio calculating section 12-2 to 12-N calculates an analog interference wave equivalent C/N ratio corresponding to the added D/U ratio of the analog interference waves. Each of the arithmetic units 10-2 to 10-N handles the calculated analog interference equivalent C/N ratio as an analog interference wave equivalent C/N ratio at the relay station of a calculation target. Each of equivalent C/N ratio adding sections 15-2 to 15-N adds a digital interference wave equivalent C/N ratio, apparatus deterioration equivalent C/N ratio, the analog interference wave equivalent C/N ratio and the like and outputs an output signal C/N ratio. <P>COPYRIGHT: (C)2010,JPO&INPIT |
