Amplitude Modulation Theory: In Amplitude Modulation Theory, the amplitude of a carrier signal is varied by the modulating voltage, whose frequency is invariably lower than that of the carrier. In…
Need of Modulation in Communication System: Until the process of superimposing a low-frequency (long-wave) voice information component on a high-frequency (short-wave) carrier signal was perfected, the most widely used form…
Delta Modulation(DM): Delta modulation(DM) is process of modulation in which train of fixed width pulses is transmitted. Their polarity indicates whether the demodulator output should rise or fall at each…
Pulse Code Modulation(PCM): Pulse Code Modulation(PCM) is different from the other forms of pulse modulation studied so far, PCM also uses sampling techniques, but it differs from the others in…
Pulse Position Modulation(PPM): In this Pulse Position Modulation system, the amplitude and width of pulses is kept constant, while the position of each pulse, in relation to the position of…
Pulse Width Modulation(PWM): Pulse width modulation of PTM is also often called Pulse Duration Modulation (PDM). In this system, shown in Fig. 18.8, we have a fixed amplitude and starting…
Pulse Time Modulation(PTM): In Pulse Time Modulation the signal is sampled in the same way as in PAM, but the pulses indicating instantaneous sample amplitudes have a constant amplitude themselves.…
Pulse Amplitude Modulation(PAM): Pulse Amplitude Modulation(PAM) is the simplest form of Pulse Modulation. It is shown in Fig. 18.7. PAM is a pulse modulation system in which the signal is…