Amostragem e reconstrução de sinais

Abstract

This work presents the study performed to develop a didactic module using hardware and software solutions in order to demonstrate the sampling theory in classes. It provides the mathematical model of the sampling processes and analog signal reconstruction, which involves repeated and mirrored spectrum and filtering of audio signals so that spectral overlapping doesn’t happen. In order to validate the module developed in this work, three scenarios were used: 1 – Digital Signal Processing (DSP) system with implementations of both antialiasing and reconstruction filters; 2- DSP system without the antialiasing filter; 3 – DSP system with an inappropriately implemented antialiasing filter. Given these three scenarios, it was possible to measure the impact caused by the aliasing effect and the model requirements to avoid it, and also present to the students a visual and auditory perception of the effects caused by the aliasing in the sampled signals. It was also possible to show the students the appropriate way to avoid aliasing when sampling signals.