B3-Multipath Propagation

=⌘ B3-Multipath Propagation =

=⌘Multipath and how to use it=

Note: The mobile phone users will typically not have a direct link between the mobile phone and the antennas of the base station in a typical environment. Such a situation, where the mobile communication has to go "around a building" or "around the corner" are called NLOS, non Line-of-Sight connection. As compared to a Line-of-Sight LOS connection the signal is typically reduced by some 20-30 dB.

=⌘ Boundary conditions =
 * What is happening on electrical walls, magnetic walls?



Scattering, reflection and diffraction ( explain differences ) are the three major components in wave propagation. Ideal reflection environments are characterised through $$ |r| =1,\ \ \phi_r=180\deg $$

Related physics
Free Space impedance $$Z_0 $$ as connection of permeability $$\mu_0$$ and permittivity $$\varepsilon_0$$.

$$ \mu_0=4 \pi \cdot \10^{-7} N/A^2$$. The unit of $$\mu_0$$ is $$Newton/Ampere^2 = N/A^2 = kg m/s^2 1/A^2$$

$$\varepsilon_0=\frac{1}{\mu_0 c^2} $$ $$ = 8.854 \cdot \10^{-12} F/m$$.

The unit of $$\varepsilon_0$$ is Farad/m: $$F/m = A s/V = A^2 s^4/(kg m^2)$$

= Diffraction = Diffraction is the transforming of a wave at an object, typical edge of a house ("edge diffraction") or the roof-top

= Scattering = Interaction with object being about the same size as the wavelength, $$ lambda... $$