| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and device for estimation of video quality in an optical video distribution system, capable of quantitatively estimating effect to a transmission quality due to SPM that occurs in transmission path at short times. SOLUTION: The video quality estimation method has a first step for calculating CNR<SB>RIN</SB>corresponding to RIN after transmission based on a specified calculation formula, a second step for calculating a time waveform of a non-modulated IF signal after transmission and calculating a Duty ratio of a duration of a voltage value of 0 V or more to a duration of one cycle based on the acquired time waveform after transmission, a third step for input of characteristics of Duty ratio to CNR in an optical receiver of the optical video distribution system, which is acquired in advance through measurement, and calculating CNR<SB>Duty</SB>corresponding to the Duty ratio calculated at the second step with comparing with the characteristics of Duty ratio to CNR, and a fourth step for calculating a total CNR based on a specified calculation formula by using the CNR<SB>RIN</SB>calculated at the first step and the CNR<SB>Duty</SB>calculated at the third step. COPYRIGHT: (C)2011,JPO&INPIT
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