| 摘要 |
<p>Method and apparatus for providing a sequence of digitized samples to a modem in substantial synchronism with the incoming signal baud rate, but without using a variable sampling frequency. An incoming signal is sampled at a fixed rate, stored temporariy in a buffer memory, and then interpolated using a digital interpolation filter to provide a sequence of interpolated samples that are equivalent to those that wou!d have been obtained if a variable-frequency sampling rate had been used. Any relative delay between the samples supplied to the modem and the baud rate is sensed and accumulated in an up/down counter. Then the accumulated delay stored in the counter is used to control the selection of coefficients for the interpolation filter.</p> |
