| 摘要 |
PROBLEM TO BE SOLVED: To measure the jitter of a program clock reference(PCR), frequency offset and a drift rate in a motion picture engineering group(MPEG) by utilizing a selectable constant measurement bandwidth when PCR arrival time is unequal and a PCR rate is variable. SOLUTION: An interval PCR-int(n) of PCR arrival time is measured by an asynchronous and accurate reference oscillator, the selectable constant measurement band-width BW is fixed on a constant measurement bandwidth for demarcating the frequency of a jitter from that of a wander independently of the variable PCR rate and the jitter Jit(n) of the PCR, frequency offset FO(n) and the drift rate DR(n) are measured in accordance with the interval of PCR arrival time, a PCR value PCR(n) at each PCR arrival time and the fixed selectable constant measurement bandwidth by using a format of a pair of differential equations. |
