The Digital FM Broadcast Exciter Based On DSP

FM broadcast is one of the important method of public media and the significant outside propagate channel. Exciter is the core component of FM broadcast transmitter. It is used to make the audio signal modulate the carrier radio. The working of the exciter directly influence the quality of the FM broadcast signal. Now days analog FM exciters are universally applied in the transmitters of every radio station. The analog FM exciter which abides the Pilot frequency-FM standard has developed for more than 60 years. It has reached a mature stage and can't be eminently improved in some important indexes such as frequency response, distortion, signal to noise ratio(S/N). In recent years with the development of digital signal processing technology, digital FM exciter is increasingly being taken in attention by it's eminent standard such as high S/N, low distortion. But it is not be put into use because of the barrier of price. In our country digital FM exciter is basically rely on import. So the research on digital FM exciter is of great significance to lower the cost of broadcast equipment and improve the quality of broadcast.This essay firstly introduces the developing situation of digital FM exciter and the trend of digital exciter replacing analog exciter. Then the essay analysis the concern regulations of pilot-FM broadcast and carry out the idea of designing composite signal part accordingly. After that the essay introduces the designing of front channel and the choice of the concerned component and chip. In the end the essay analysis's the configuration and programmer of the TMS320C55x series DSP chips and the way that abides the regulations of pilot-FM broadcast to composite signal.