Question

Why PCM is called a modulation technique?

Answer 1

Modulation:

1. Modulation is a process in which parameters of a career signal are varied according to the instantaneous value of the message signal.
2. There are various types of modulation depending upon the modulation of various factors (like frequency, amplitude, etc.) on each of the modulation signals.
3. Digital modulation is used for digitalized platforms. It is of 3 types, namely, Pulse Amplitude Modulation (PAM), Pulse Width Modulation (PWM) and Pulse Code Modulation (PCM).

Pulse Code Modulation:

1. In Pulse Code Modulation, analog information is converted to a binary sequence.
2. The amplitude in analog signal is regularly tested, and all signals are quantized to the nearest value.
3. When a digital signal goes through PCM, the information is converted from analog form to binary form $\left(0,1\right)$.
4. Hence, this process is a modulation technique, specifically digital modulation.

PCM output of the instantaneous values of a sine wave

Thus, PCM is a modulation technique.