DIGITAL ALGORITHM FOR SUPPRESSION OF ADJACENT CHANNEL INTERFERER IN FM BROADCASTING

This paper deals with adjacent channel interference in FM broadcasting . We consider the problem of the adjacent channel interference with on e interferer with a carrier offset of 100 kHz, which is the ''worst ca se'', because the bandwith of the two FM signals is about 200 kHz, so that we have overlapping spectra. A conventional digital FM-demodulato r is compared with a new digital compensation algorithm using stereo m odel processes. The compensation algorithm uses the information of the envelope of the input signal, in order to improve the signal-to-noise ratio at the output of the demodulator. Simulation results show an im provement of more than 10 dB, if we have a measurement bandwidth of 53 kHz (= bandwidth of the stereo multiplex signal) and the amplitude ra tio rho between the interferer and the desired signal is less than 1.0 and greater than 0.1.