Disadvantages of Pulse Amplitude Modulated (PAM) Signal
Following are the drawbacks of a PAM signal:
(i) The bandwidth required for the transmission of a PAM signal is very large in comparison to the maximum frequency present in the modulating signal.
(ii) Since the amplitude of the PAM pulses varies in accordance with the modulating signal therefore the interference of noise is maximum in a PAM signal. This noise cannot be removed easily.
(iii) Since the amplitude of the PAM signal varies, therefore, this also varies the peak power required by the transmitter with modulating signal.