11. Pathloss, Shadowing and Multipath Altogether

Pathloss, Shadowing and Multipath Altogether – Transcript:

• Now let’s look at all that – when we take all of those effects together
• Starting with pathloss (at a given carrier frequency) – the received signal decreases logaritmically with the distance in a smooth manner
• Then we add shadowing – „slow fading” (aka large scale fading) – the signal decayes with some smooth modifications over time
• Finally when we add multipath – „fast fading” (aka small scale fading) – the signal rapidly oscillates along the average value

• Here is an exmple of a simulation where we have an map of a flat, with a placement of wifi access point in placed in the corner, and we can see how the signal propagates and how it value changes on the position depending on „the obstacles”
• That differs of course of the type of the obstacle – e.g. the wall and its type (concrete or carton/plastic”) window, glass door, open space, etc.

• Here is the same „flat” / office but we move the locaiton of the transmitter (AP), and we can see that depending on the location of the AP, the signal level in the same locaiton varies depending on the transmitter location