DIGITAL MODULATION MODE
3-42
Modulation fading
The signal generator is able to simulate the effects of fading in a transmission system. Pressing the
[Fading Control]
key on the
Sig Gen
menu causes the
Digital Modulation Fading Control
menu
shown in Fig. 3-42 to be displayed.
LOCAL
Fading
Disabled
Rayleigh
Fading
Rician
Fading
Direct
Doppler
Doppler
Speed
Path
Ratio
C0849
Digital Modulation Fading Control
Doppler Speed
: 0 Hz
Direct Path Doppler : 0 Hz
Path Ratio
: 0 dB
(Direct/Scattered)
Fading Control: RAYLEIGH
Fig. 3-42 Digital modulation: Fading control menu showing Rayleigh fading selected
Select between the two types of fading by pressing the
[Rayleigh Fading]
or
[Rician Fading]
key.
Doppler speed for Rayleigh fading and the scattered path for Rician fading can be entered using
the
[Doppler Speed]
key.
To set the direct/scattered path ratio for Rician fading, press the
[Path Ratio]
key, enter the path
ratio in dB (positive or negative) and terminate the entry with the [dB] key. The direct path
doppler speed for Rician fading can be entered using the
[Direct Doppler]
key. The entered value
must be within a factor of 2 of the scattered path doppler.
When not required fading can be disabled using the
[Fading Disabled]
key.
Note that when Rayleigh fading is enabled the direct path doppler and the path ratio settings are
ignored.
Menu exit
Press
[SIG GEN]
to return to the
Sig Gen
menu where further selections may be made.