Demodulating FSK signal, using only frequency sample value

Hello guys,

I have signal in .binIQ format which contains imaginary and real part. I succesfully upload this file into the matlab create a valuable signal (Q+I).

In the picture on left side we can see a row with 2mil samples and in the picture on right is a zoomed one data burst.

From this signal I need to determine frequency shift, f1 & f2 because it is a FSK modulation. The only information whit I can work here is sampling frequency on 2.75 Mhz. (This signal have been already processed in AKRS so I know, that frequency shit is on +-150Khz, but I have to work without this information ).

My purpose here is to demodulate this signal and get data in binary form.

frequency spectrum