Patent ID: 6870492

Claim:
A sampling rate converter for altering an initial sampling rate to a desired sampling rate resulting in near-unity fractional sampling rate alteration, comprising: an interpolator for receiving and up-sampling digital data representing a continuous waveform signal, the digital data having a first sampling rate, wherein the interpolator produces upsampled and filtered data at a second rate; a clamped cubic spline (CCS) intepolator for producing down sampled data based on the upsampled and filtered data wherein a ratio defined by the first and second data rates is near-unity; and wherein the CCS intepolator implements a cubic polynomial in logic, and further wherein the CCS interpolator includes: derivative estimation block for producing derivative estimates of a data sequence; CCS coefficient calculation block for producing coefficient values of the cubic polynomial based on the derivative estimates and a buffered sequence of samples; and CCS evaluation block for producing the down sampled data based upon the derivative estimates, the coefficient values of the cubic polynomial and a specified value of time, x, and further based upon a trigger to produce the down sampled data.