fm demodulation of recorded data using simulink

hello I'm trying to input a very low frequency signal to the pc using the sound card. In order to do so, I had to change i't frequency using FM modulation which was done using timer 555. I need to demodulated it after recording in simulink, but all the blocks have frequency deviation which I don't know. Timer 555 ic only allows you to control the carrier frequency. how do I demodulate the signal?

Answer 1

[Ed Marquez]

As you mentioned, it is necessary to know the frequency deviation in order to use the FM demodulation blocks in Simulink.

Note that you can attempt to obtain that frequency deviation if you know the maximum frequency of the message signal and the carrier frequency.

Furthermore, you can take a look at the example provided in the link below to calculate frequency deviation from FM equation:

http://www.careerride.com/view/frequency-deviation-calculation-from-fm-equation-21879.aspx

[isra]

But what will the modulation index (k) be?