Editing Path loss (section)

== Overview ==
In wireless communications, path loss is the reduction in signal strength as the signal travels from a transmitter to a receiver, and is an application for verifying the loss. There are several factors that affect this:

*Free-space path loss: This is the fundamental loss that occurs due to the spreading of the radio wave as it propagates through space. <ref>https://semfionetworks.com/blog/free-space-path-loss-diagrams/</ref> It follows an inverse square law, meaning the signal strength decreases proportionally to the square of the distance between the transmitter and receiver.

* Diffraction: When a radio wave encounters an obstacle, it can be diffracted, or bent around the edge of the obstacle. This can cause additional signal loss, especially in urban environments with many buildings. <ref> https://www.researchgate.net/figure/llustration-of-reflection-diffraction-scattering-and-absorption_fig2_228041875</ref>

*Absorption: Certain atmospheric gases and obstacles like buildings and foliage can absorb radio waves, reducing their strength.<ref>https://www.twc-net.com/blog/uncategorized/a46</ref>

* Reflection and scattering: Radio waves can be reflected off surfaces like buildings and the ground, and scattered by objects like trees and lampposts. This can lead to multipath propagation, where the receiver receives multiple copies of the signal that may interfere with each other. <ref> https://www.researchgate.net/figure/Reflection-scattering-and-diffraction-of-signal-Tait-Communications-2015_fig1_326705984</ref>

In understanding path loss and minimizing it, there are four key factors to consider in designing a wireless communication system:

1) Determining the required transmitter power: The transmitter must have enough power to overcome the path loss in order for the signal to reach the receiver with sufficient strength.

2) Determine the appropriate antenna design and gain: Antennas with higher gain can focus the waves in a specific direction, reducing the path loss.

3) Optimize modulation scheme: The choice of modulation scheme can affect the robustness of the signal to path loss.

4) Set the receiver sensitivity appropriately: The receiver must be sensitive enough to detect weak signals.