Processamento digital de sinais aplicado a detecção automática da modulação em rádio definido por software.

Abstract

In this work it was implemented a software radio to automatically identify the modulation type of a signal received by its antenna. Using an USRP (Universal Software Radio Peripheral), we received signals from AM and FM broadcasting stations in Campina Grande, digitalized and sent these signals to a computer to process them. This processing was implemented in GNU Radio from which we obtain a parameter, to quantify the variation in the received signals amplitude and classify their modulation type after doing a comparison with the treshold specified by the used technique. It was verified that even for signals received from comercial stations, with noise and imperfections, the system was capable of correctly identifying their modulation types.