Question

Which one of the following is not classified as pulse modulation?

• A. \(\text{Pulse duration modulation} \)
• B. \(\text{Pulse Amplitude Modulation} \)
• C. \(\text{Pulse band Modulation} \)
• D. \(\text{Pulse position Modulation} \)

Hint:

Pulse modulation techniques mainly include Pulse Amplitude Modulation (PAM), Pulse Width Modulation (PWM), and Pulse Position Modulation (PPM). "Pulse Band Modulation" is not a standard classification.

Answer 1

The Correct Option is C

Step 1: Understanding Pulse Modulation
Pulse modulation refers to a technique where the message signal is encoded in the form of pulses. The major types of pulse modulation are:
- Pulse Amplitude Modulation (PAM): The amplitude of the pulses is varied according to the message signal.
- Pulse Duration Modulation (PDM) or Pulse Width Modulation (PWM): The width of each pulse is varied according to the message signal.
- Pulse Position Modulation (PPM): The position of each pulse is varied according to the message signal.
Step 2: Identifying the Incorrect Option
- The given options (1), (2), and (4) are recognized types of pulse modulation.
- Pulse Band Modulation (PBM) is not a recognized type of pulse modulation. Modulation techniques primarily fall into analog modulation (AM, FM, PM) or pulse modulation (PAM, PWM, PPM, PCM).
Thus, option (3) - "Pulse band Modulation" is incorrect.
Final Answer: The correct choice is Option (3): Pulse band Modulation, as it is not a classified pulse modulation technique.