Modem Definition: The term Modem Definition is an acronym for modulator-demodulator. The primary modem function is to convert digital data into an analog form which is suitable for transmission on common carrier circuits (example telephone…
Pulse Wave Code Format: There are many different code formats of pulse wave. The classification is based on three criteria, namely, form of information transmission, relation to zero level, and direction. Based on the 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. The input is caused…
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 that it is a digital…
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 a recurrent reference pulse, is…
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 time of each pulse, but…
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. However, one of their timing…
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 sampled at regular intervals, with…
Pulse Modulation: Pulse modulation may be used to transmit analog information, such as continuous speech or data. It is a system in which continuous waveforms are sampled at regular intervals. Information regarding the signal is…
Time Division Multiplexing(TDM): Time Division Multiplexing - Any pulse modulation scheme involves translating the audio, or modulating signal into a series of encoded pulses, sending these pulses over a transmission medium and reverting the pulses…
