Construction of Pulse Amplitude Modulation
An amplitude modulation circuit, a carrier signal source, and a pulse generator can be used in a simple arrangement to generate a Pulse Amplitude Modulation (PAM) signal.
- The signal that modifies the carrier signal’s amplitude is produced by the modulating signal generator. Depending on the application, this signal might include any desirable waveform (sine, square, etc.).
- Carrier signal source produces the carrier signal. This signal is usually a high-frequency waveform, most frequently a sine wave.
- The PAM signal is created by this circuit by combining the modulating and carrier signals. The carrier signal’s amplitude is managed by the modulating signal.
Pulse Amplitude Modulation
Pulse Amplitude Modulation (PAM) is a key modulation technique used in digital communication for transmitting analog data and is one of the most widely used types of analog-to-digital conversion. Its process is simple where the amplitude of a sequence of pulses changes with the instantaneous amplitude of the analog message signal. The analog signal that is to be modulated is sampled by a sequence of pulses that are amplitude-modulated on the carrier to produce the amplitude-modulated pulses.
The analog signal is sampled at regular intervals to enable the amplitude of pulses due to be produced by the carrier to be varied. The sampled values are quantized to a specific number of quantization levels or discrete levels whereupon the process is repeated. Due to its simplicity of implementation and analysis, PAM is often employed in many applications including digital communication, audio transmission, and instrumentation among others. One of the biggest drawbacks of PCM is its sensitivity towards channel errors, as poor-quality channels will introduce noise and distortion, particularly over larger distances and lower data rates.
Table of Content
- What is PAM?
- PAM Block Diagram
- Types
- Mathematical expression
- Construction
- PAM Circuit
- Solved Examples on PAM
- Applications
- Advantages
- Disadvantages