Signal Impairment and Propagation Channel — Lesson 2

This lesson covers the concept of signal impairment and propagation channel, focusing on the effects of the ionosphere and troposphere on signal propagation. It delves into the impact of rain on signal attenuation and the role of temperature in the formation of water droplets and ice in the atmosphere. The lesson also explains the concept of specific attenuation and how it is influenced by factors such as frequency, polarization, and rain rate. It further discusses other potential sources of signal attenuation such as gaseous absorption, cloud absorption, and melting layer attenuation. The lesson concludes with an exploration of fade mitigation techniques and their application in real-world scenarios.

Video Highlights

00:18 - Introduction
01:08 - Rain affects signal attenuation at different frequency levels
04:46 - Example problem
06:48 - Atmospheric impairments
13:05 - Combined propagation effects
15:03 - Objective and principles of FMT
19:50 - Power control FMT
28:30 - Signal processing FMT

Key Takeaways

- Signal impairment occurs due to various factors including the ionosphere, troposphere, and rain.
- Specific attenuation, measured in dB per kilometer, is influenced by frequency, polarization, and rain rate.
- Other potential sources of signal attenuation include gaseous absorption, cloud absorption, and melting layer attenuation.
- Fade mitigation techniques are used to counter the effects of signal attenuation. These techniques include power control, signal processing, diversity, and layer two techniques.
- The effectiveness of fade mitigation techniques depends on the specific circumstances and requirements of the signal propagation.