Sampling Rate Conversion
Jan Vitasek
DOI:
Abstract
The topic of this article is conversion of the signal with given sampling frequency to signal with another sampling rate. The task is to change the sampling rate from fvz3=500Hz to fvz4=360Hz. There are two methods; in the text are called Method A and Method B. The Method B has two approximations, first and second order. The basic idea of Method A is to find the least common multiple. It has to use integrator (low-pass filter, cut frequency is half of original signal) and decimator (low-pass filter, cut frequency is half of final signal). At first the zero samples are pasted, these are filtered by low-pass filter and then the computed samples are selected. The method B is not so exacting for computation, because the integrate factor is smaller, than in the method A. Of course, there are used integrate filters (low-pass filter). The first order approximation selects the nearer sample of both border samples. The second order approximation interpolates samples by line. Selected sample is therefore more accurate.