| 摘要 |
<p>The present invention relates to a method for determination, with a reduced quantization error, a ratio of the frequencies of two periodic signals, comprising the steps of receiving two periodic signals x 1 (101) and X2, having frequencies f 1 and f2 respectively; adjusting a measurement time interval of length T m that equals a natural number m times the period 1/f1; deriving a periodic signal xs (106) with a frequency f 5, from X2 in such a way that f 5= (mn+ 1)/T m, in which n is also a natural number; determining the average phase of the signal x5 with respect to the average phase of the signal X1, over a first time interval of the length T m by counting the number of periods of x5 that elapsed since the start of the first time interval, and determining the ratio of the sum of those count numbers that follow either the positive or the negative transitions of the signal X1, and the number of transitions of x 1 over the first time interval; determining the average phase of the signal x5 with respect to the average phase of the signal x 1, over a second time interval of the length T subsequent to the first time interval; determining the frequency ratio f 1 /f 5 and dividing this by the average number of periods of x 1 found over the two subsequent time intervals.</p> |
