A MATLAB®-Based FM Demodulator for the Radio Broadcast Data System

A MATLAB®-based FM demodulator for the RBDS system was designed to investigate software-based FM demodulator techniques. An overview of the operation of FM decoder design is presented. The FM radio signal contains stereo/audio, as well as RBDS data. This thesis develops a FM radio receiver that extracts these message elements from the RBDS data and displays the message details in a user-friendly format. An Agilent vector signal analyzer (VSA-89600) is used to capture radio signals from a local radio station, and to convert this received FM radio signal into a MATLAB®- compatible format. The signal is then recorded on the host computer and processed using signal processing algorithms. Derivations and designs are done for various blocks of the processing chain to extract the RBDS signal from the FM radio signal, to demodulate this signal and recover the RBDS message (bits), and to decode these bits into a text message that is understandable by any user. Experimental results regarding message details of the received signal show a successful match with the original message information obtained from the radio station