| 摘要 |
A system and method are provided for efficiently switching a loop bandwidth using stored values in a digital filter of a phase-locked loop system. In a first timeslice, an input signal is digitally filtered using base coefficients multiplied by stored filter output and input values from previous timeslices. The filter output value is used to acquire the input signal frequency in a first bandwidth. In response to changes in the input signal frequency, the input signal is digitally filtered in a predetermined number of first intermediate period timeslices using transient coefficients multiplied by stored filter output and input values from previous timeslices. As a result, the first filter output value is maintained within a predetermined range. In a second timeslice, the input signal is digitally filtered using base coefficients multiplied by stored filter output and input values from previous timeslices to acquire the input signal frequency in a second bandwidth.
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