Drawbacks of PAM method

Drawback of using PAM method is

Options:

a) Bandwidth is very large as compared to modulating signal
b) Varying amplitude of carrier varies the peak power required for transmission
c) Due to varying amplitude of carrier, it is difficult to remove noise at receiver
d) All of the above

Correct Answer: All of the above

Explanation:

In PAM, Bandwidth is very large as compared to modulating signal frequency. In PAM, the amplitude of the rectangular pulse train is varied according to the instantaneous value of the modulating signal. Due to this, the required power for transmission is also varied. Due to varying amplitude of carrier, the interference of noise is very high in PAM. So it is difficult to remove noise at receiver.