@月合大等 Content Three Phenomena in Wireless Channel Path loss and shadowing ■Multipath fading Stochastic characterization of multipath fading Duality of multipath fading WSSUS assumption on multipath fading A review of propagation channel modelling Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 20/199
Content Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 20 / 199 ■ Three Phenomena in Wireless Channel ■ Path loss and shadowing ■ Multipath fading ■ Stochastic characterization of multipath fading ■ Duality of multipath fading ■ WSSUS assumption on multipath fading ■ A review of propagation channel modelling
@月冷大等 Path loss Caused by Dissipation of the power radiated by the transmitter ■ Effects(caused by terrains)of the propagation channel 528 100 524 57 538 52日 .0 10012014016016020022024020280300 Frequency(GHz) Manhattan Path Loss versus Distance 0.2 di n=6 n=5 2 130 80 LOS 0 60 n-3 80 (-914 MHz 40 0 n=3.54 Bo 0=12.8d n=2 =168 50 n=l 1345 23456 10 100 Transmitter-Receiver Separotion (m) Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 21/199
Path loss Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 21 / 199 Caused by ■ Dissipation of the power radiated by the transmitter ■ Effects (caused by terrains) of the propagation channel
@月命大凳 Theoretical Path loss in free space Find the electric field intensity caused by a line charge with length L and charge density p. Let the z-axis of a cylindrical coor- dinate system coincide with the line charge and the mid point of the line be at the origin. Evaluate directly the electric poten- tial and the electric field intensi- ty.From=亮J产品d北， we obtain(sin a2 sin a1)ez -(cos a2-cos a1)er] ■Only when L→o,then a1→0 anda2→元，E=er Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 22/199
Theoretical Path loss in free space Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 22 / 199 x z y r 2 1 r O r ! r dz z r z e r e , ) 2 P ( r, z It is impossible to apply Gauss’ law to calculate the field because Find the electric field intensity caused by a line charge with length L and charge density ρ. ■ Let the z-axis of a cylindrical coordinate system coincide with the line charge and the mid point of the line be at the origin. ■ Evaluate directly the electric potential and the electric field intensity. From E = ρl 4πǫ 0 R L 2 − L 2 r − r ′ |r − r ′ | 3 d l ′ , we obtain E = ρl 4πǫ 0 r [(sin α 2 − sin α 1 ) e z − (cos α 2 − cos α 1 ) e r] ■ Only when L → ∞, then α 1 → 0 and α 2 → π, E = ρl 2πǫ 0 r e r
@月傍大学 Path loss 入2 PR=PrGrGRATD2 Shadowing f倒-anN0 10 (1010g10-(dBm)) Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 23/199
Path loss Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 23 / 199 PR = PTGTGR λ2 4πD2 Shadowing fΩp (x) = 10 xσΩp√2π ln 10 exp "−10 log10 x − µΩp(dBm)2 2σ2Ωp #