1. Propagation Measurements and Models for Wireless Communication Channels
指導教授：黃文傑 老師
學　　生：曾凱霖
學　　號：M
無線通訊實驗室

2. Outline 1、 The Physics of Propagation 2、 Outdoor Propagation
3、 Indoor Propagation
4、 RF Penetration into Building
5、 Conclusion

3. The Physics of Propagation
Path parameters
1、Path Loss-
log-distance path model：
log normal shadowing：
2、Multipath Delay Spread-

8. Outdoor Propagation Macrocells Microcells 1、Microcellular Systems-
2、Street Microcells-

11. Indoor Propagation Propagation inside signal-story buildings
1、Temporal Fading for fixed and moving
terminal
2、Multipath delay spread-
3、Path loss-
Propagation Between Floors
Computer-aided Design for in-building propagation prediction

14. RF Penetration into Building
Floors & attenuations
Penetration loss decreases with increasing frequency

15. Conclusion 3D numerical modeling
(time delay statistic, coverage,interference)
Higher data rates
AOA statistics in different enviroments

16. 劇終

17. Effect of mobility in communication systems

18. Effect of mobility in communication systems (cont.)

19. Effect of mobility in communication systems (cont.)

20. Radio Propagation Introduction (1) focus on bands around a few G Hz
BW is limited in the lower bands
penetration is very low above these bands
Advantages:
1 W power can penetrate several floors in a building and a few miles outdoor
Antenna ~ a few inches
A few inches of antenna separation can provide diversity gain.

21. Introduction(2) 3 design issues
10 ~ 30 G Hz - signals are confined in a room. Can extend throughout the building by leaky cable antennas
3 design issues
signal coverage -- determines the cell size or service area
max data rate -- determines the network throughput
channel fluctuation rate -- determines the timing and phase recoverage circuit and the power control algorithm

22. Multipath Fading (2)
Amplitude and phase fluctuation caused by attenuation and difference path length
Exact analysis -- solving Maxwell equation with boundary conditions
Ray-tracing method -- use geometric optic approach and treat propagation as rays, can also include transmission through walls and diffraction at building edges

23. Example 3 : (2D ray tracing inside a room)
Vertically polarized antenna
reflections from the walls dominate
LOS
LOS + First Order

24. Example 3 Second & higher order reflections contribute very little
with 4 walls there are 4 first order reflections, 12 second order reflections 48 third order reflections
Rays arrive with different amplitudes & phases
∴by central limit theorem, the combined signal is a zero mean Gaussian R.V.
The LOS signal adds a non-zero mean to it.
The amplitude of a complex Gaussian variable has a Rician distribution
reduces to Rayleigh distribution for zero mean case