Pulse Amplitude Modulation (PAM) is a pulse analog modulation scheme in which the amplitudes of a train of carrier pulse are varied according to the amplitude variations of message signal.
In pulse analog modulation pulse by pulse transmission will occured each of the pulse to be transmitted corresponds to baseband signal and can be directly transmitted through baseband channel only.
- PAM signal can be generated either using natural sampling or using flat-top sampling as shown in the figure of this video.
- PAM Generator consists of LPF, a multiplier and a pulse generator.
- Initially the modulation signal m(t) is passed through LPF to bandllimit the message signal.
- The bandlimiting is necessary to avoid aliasing effect in the sampling process.