Applications of Pulse Amplitude Modulation
- To send digital data over phone lines, digital subscriber line (DSL) modems use PAM.
- Pulse code modulation is used in audio CDs to encode analog audio signals into digital form.
- Digital data is sent across optical fibers using PAM in fiber optic communications.
- Physiological signals are sent over PAM in biomedical signal processing, including electrocardiography (ECG).
- Pulse width modulation (PWM) techniques are used in PAM-based industrial automation systems to control motor speed and position.
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