FM - Pre emphasis

Pre emphasis is done

Options:

a) For boosting of modulating signal voltage
b) For modulating signals at higher frequencies
c) In FM before modulation
d) All of the above

Correct Answer: All of the above

Explanation:

Pre-emphasis is done for boosting the relative amplitudes of the modulating voltages at higher audio frequencies. In this method, the artificial emphasis of high frequency components of message signal is done before modulation in the transmitter. This is done because the noise is louder at higher frequencies. So pre emphasis is done before the noise is added in the communication channel.