JPL's Wireless Communication Reference Website

Chapter: Wireless Channels
Section: Multipath fading, Rayleigh fading

Animation of Rayleigh fading

In this JAVATM 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

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).
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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 1996