The invention relates to a
system and a method which demodulates the frequency-modulation
signal, which solves the compatibility issue of analog FM
demodulation in digital mobile interphone
system, comprising the following steps: firstly, sampling the input analog FM
signal by data sampling module; secondly, removing carrier of the FM data by carrier removal module; thirdly, analyzing the removedcarrier
signal of IQ dual to revivify the modulated signal by
baseband analytic module; finally, outputting the final modulated signal by lowpass module. The functions of
clock module, carrier removal module,
baseband analytic module and lowpass module can be realized by a FPGA. The invention has an
advantage of achieving the compatibility of analog FM
demodulation and the digital treatment of
analog signal in digital mobile interphone
system, so as to enhance the signal anti-interference capability.