https://www.mathworks.com/help/comm/ref/cpfskdemodulatorbaseband.html
CPFSK Demodulator Baseband - Demodulate CPFSK-modulated data - Simulink
The CPFSK Demodulator Baseband block demodulates a signal that was modulated using the continuous phase frequency shift keying (CPFSK) method.
cpfskdemodulatorbasebanddemodulatemodulated