Animation of Rayleigh fading

In this JAVA^TM applet, Rayleigh fading is simulated by taking four reflected and scattered waves. Their relative amplitudes are 0.574, 0.533, 0.462 and 0.417. The Doppler shifts are chosen to lead to a Doppler spread of 1 Hz. This a relatively slow type of fading, that could occur in an indoor propagation environment. Often Doppler spreads of 50 - 100 Hz are experienced in vehicular reception above 1 GHz.

Figure: Approximation (orange) of Theoretical Doppler Spectrum (Black)

We took

+ 0.9 Hz, this would correspond to a wave arriving from 25 ° relative to the motion of the vehicle.
- 0.62 Hz, angle of arrival 128 °
+ 0.21 Hz, angle of arrival 78 °
- 1 Hz, the largest shift of all, angle of arrival -180 °, i.e., from behind the vehicle.

Note that in a typical Doppler spectrum, shifts of about the maximum value are more likely than shifts nearer to 0 Hz.

Java Applet: Phasor diagram of 4 scattered waves (in blue),
resulting an approximately Rayleigh-fading envelope (in black). .

Java Applet: Phasor diagram of 9 scattered waves (in blue),
resulting an approximately Rayleigh-fading envelope (in black).
Click on "Settings" to change the Doppler spread (by carrier frequency
and antenna speed) or to see the amplitude evolve as a function of time.

JPL's Wireless Communication Reference Website

Chapter: Wireless Channels Section: Multipath fading, Rayleigh fading

Animation of Rayleigh fading

JPL's Wireless Communication Reference Website © 1996

Chapter: Wireless Channels
Section: Multipath fading, Rayleigh fading