@月命大 Mechanism identified by polarization properties XPDs versus the interaction type: Group Interaction type/scatterers XPDs in dB along the propagation path T,1 T0,2 1 Diffraction around the roof [15,281 [16,30] edge of B3 2a Reflection/scattering by [-10,17 [-6,16] at least one tree 2b Reflection/scattering only [5,22] -6,16 by man-made structures Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 62/199
Mechanism identified by polarization properties Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 62 / 199 XPDs versus the interaction type: Group Interaction type/scatterers XPDs in dB along the propagation path rˆℓ, 1 rˆℓ, 2 1 Diffraction around the roof [15, 28] [16, 30] edge of B3 2a Reflection/scattering by [−10, 17] [− 6, 16] at least one tree 2b Reflection/scattering only [5, 22] [− 6, 16] by man-made structures
@月冷大学 Modeling channels based on mechanism Modeling channel composition based on propagation mechanisms. Specular/reflected paths and the diffracted paths are identified. The former paths exhibit less path loss than the latter paths. UE# 8 ·: UE #7 Rel.power [dB] Figure 4.Estimated paths superimposed on a panoraic photograph taken from the BS location at the roof.The directions of the UE locations are indicated with green circles.It should be noted that the UEs are in NLOS conditions so that they are not visible from the BS. Medbo,J.;Asplund,H.;Berg,J.E.&Jalden,N.Directional channel characteristics in elevation and azimuth at an urban macrocell base station Antennas and Propagation (EUCAP),2012 6th European Conference on,2012,428-432 Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 63/199
Modeling channels based on mechanism Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 63 / 199 ■ Modeling channel composition based on propagation mechanisms. ■ Specular/reflected paths and the diffracted paths are identified. ■ The former paths exhibit less path loss than the latter paths. Rel. power [dB] 0 -5 -10 -15 -20 -25 -30 UE #7 UE #1 Figure 4. Estimated paths superimposed on a panoraic photograph taken from the BS location at the roof. The directions of the UE locations are indicated with green circles. It should be noted that the UEs are in NLOS conditions so that they are not visible from the BS. Medbo, J.; Asplund, H.; Berg, J. E. & Jalden, N. Directional channel characteristics in elevation and azimuth at an urban macrocell base station Antennas and Propagation (EUCAP), 2012 6th European Conference on, 2012, 428-432
@月命卡等 Modeling channels by mechanism [Medbo et al. 2012] Classification of paths as diffracted or specularly reflected done by means of the projected UE location h,which is [aap] obtained by extrapolating the estimat- ed wave direction at the base station to the distance corresponding to the esti- mated delay. If h is on or near ground level,the wave is classified as specular If h is significantly above ground,e.g. more than half of the height of the clos- est obstructing building,then the path [p]oe is classified as diffracted For this measurement the radio link at UE locations for which the excess loss 400 600 800 Rel.power is larger than 25 dB has a significant Propagation distance [m] [dB] contribution from diffracted paths. Figure 3.Power distributions in elevation angle and propagation distance for UE locations having excess loss less than 25 dB (upper)and higher than 25 dB(lower).Projected UE heights of -6.5,0 and 6.5 m above ground are indicated with solid lines. Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 64/199
Modeling channels by mechanism [Medbo et al. 2012] Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 64 / 199 ■ Classification of paths as diffracted or specularly reflected done by means of the projected UE location h, which is obtained by extrapolating the estimated wave direction at the base station to the distance corresponding to the estimated delay. ■ If h is on or near ground level, the wave is classified as specular ■ If h is significantly above ground, e.g. more than half of the height of the closest obstructing building, then the path is classified as diffracted ■ For this measurement the radio link at UE locations for which the excess loss is larger than 25 dB has a significant contribution from diffracted paths. extrapolating the estimated wave direction at the base station to the estimated delay. If the projected UE location is on or near ground level, the wave has whereas if the projected UE location is significantly above ground, e.g. more than half of the height of the closest obstructing building, then the path is rresponding power distributions ce for the two sets of UE locations are shown in Fig. 5. It is clear that only for the UEs having excess loss larger than 25 dB there is significant power for projected UE heights larger than 6.5 m. This is also confirmed by comparing the diffracted fraction of total power vs UE locations and excess loss shown in Fig. 4. In order to get an impression of the overall distribution of Fraction of total power classified as diffracted versus excess Rel. power [dB] Propagation distance [m] Elevation angle [deg] Elevation angle [deg] Figure 3. Power distributions in elevation angle and propagation distance for UE locations having excess loss less than 25 dB (upper) and higher than 25 dB (lower). Projected UE heights of -6.5, 0 and 6.5 m above ground are indicated with solid lines
@月冷大学 Chapter 3.2 Channel spread function Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 65/199
Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 65 / 199 Chapter 3.2 Channel spread function
@月净大等 Diagram showing the dispersion of channel in multiple dimensions Scatterer Specular path Path 1 Rx Scatterer Path D -Nominal Direction of Arrival Spread in Direction of Departure Spread in Direction of Arrival Tx Nominal Direction of Departure Moving Scatterer Dispersive path Graduate course:Propagation Channel Characterization,Parameter Estimation and Modeling 66/199
Diagram showing the dispersion of channel in multiple dimensions Graduate course: Propagation Channel Characterization, Parameter Estimation and Modeling 66 / 199 Tx Moving Scatterer Path 1 Path D Nominal Direction of Departure Nominal Direction of Arrival Rx Scatterer Scatterer Spread in Direction of Departure Spread in Direction of Arrival Specular path Dispersive path