| 摘要 |
A phase-locked loop frequency correction method and system are applied to selection of sub-bands of a multi-band voltage-controlled oscillator. The method comprises: within counting time TCNT[k], performing frequency counting on a frequency signal output by a voltage-controlled oscillator at a current working sub-band, to obtain a frequency count value FCNT[k], wherein the current working sub-band corresponds to the binary numerical value of a current node in a binary search tree (S401a); calculating an error between the FCNT[k] and a target frequency count value FCNTTARGET[k], comparing the absolute value of the error with a predetermined value, dynamically adjusting the TCNT[k] within the numerical range of the TCNT[k] according to the comparison result, and determining, in combination with a binary search algorithm, a target working sub-band at which the voltage-controlled oscillator works (S402a). The error measured is compared with the predetermined value, and therefore whether a counting time reference is added or not is controlled; a proper choice is made between correction time and correction accuracy, so as to control the correction time effectively. This dynamic correction method can effectively shorten the correction time on the whole. |
