Comparative Analysis of DSP Interpolation Process for Diverse Insertion Techniques and FIR Filtering

摘要

In many digital signal processing (DSP) applications, it is required to increase the number of samples that a discrete time signal contains; this process is called interpolation and it implies an estimation of the values to be inserted. In this work, a comparative analysis of the digital interpolation process for diverse techniques of insertion and FIR filtering is presented. The aim is to obtain the best reconstruction of a test signal which has been designed to be a simple model of a real signal. First, decimation is used up to the limit of the Nyquist theorem in order to generate the test signal. Then, this signal is fed into the interpolator, passing through two stages: 1) sample insertion, which is based on zero stuffing, zero-order hold and splines, and 2) filtering, which is based on two FIR techniques, such as time convolution and fast filtering using DFT. The results show that by using the zero stuffing technique together with the fast filtering, a despicable reconstruction error is obtained. In addition, this arrangement has the advantage of a fast response.