(1) Direct Signal: Line-of-sight transmission path
(2) Ground-reflected Signal: Reflected from ground surface
(3) Reflected Signal: Bounced from building surfaces
(4) Scattered Signal: Scattered from small obstacles (lamp posts, etc.)
(5) Diffracted Signal: Diffracted over building edges
Multipath Propagation Effects
In cellular communications, signals travel from the base station to the mobile device via multiple paths. Each path has different:
Path Length
Different distances result in varying propagation delays
Attenuation
Signal strength varies based on reflections and obstacles
Phase Shift
Different path lengths cause phase differences at receiver
Rayleigh Fading occurs when: Multiple paths combine with no dominant line-of-sight component, creating rapid amplitude variations following a Rayleigh probability distribution.