Advantages of PPM
PPM has following advantages:
(i) Due to constant amplitude of PPM pulses, the information is not contained in the amplitude. Hence, the noise added to PPM signal does not distort the information. Thus, it has good noise immunity.
(ii) It is possible to reconstruct PPM signal from the noise contaminated PPM signal. This is also possible in PWM but not possible in PAM.
(iii) Due to constant amplitude of pulses, the transmitted power always remains constant. It does not change as it used to, in PWM.
Disadvantages of PPM
The disadvantages of PPM may be listed as under:
(i) As the position of the PPM pulses is varied with respect to a reference pulse, a transmitter has to send synchronizing pulses to operate the timing circuits in the receiver. Without them, the demodulation would not be possible to achieve.
(ii) Large bandwidth is required to ensure transmission of undistorted pulses.