Propagation Measurements and Models for Wireless Communication Channels 指導教授：黃文傑 老師 學　　生：曾凱霖 學　　號：M9121014 無線通訊實驗室

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

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

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

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

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

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

劇終

Effect of mobility in communication systems

Effect of mobility in communication systems (cont.)

Effect of mobility in communication systems (cont.)

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.

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

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

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

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