using fm modulator passband in matlab
If you just want to use a black box and don't want to build the whole transmitter and receiver, you can use the FM modulator/demodulator passband present at the communication blockset=>Modulation=>Analog passband modulation.
If you would like to build the transmitter and the receiver, you can use the Voltage-controlled oscillator present at communication blockset=>comm sources=>controlled sources to build the transmitter. For the receiver, you can use PLL present at communication blockset=>modulation=>synchronization with input connected to the modulated FM signal and use the LPF output (control voltage of VCO) as the demodulated wave.
You may need at some points to use data type conversion and zero-order hold to avoid errors due to different data types and continuous waves connected to sampled ones.