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SMIQ
Fading Simulation
1125.5555.03
2.83
E-9
2.9.4.4 Menu
BIRTH-DEATH
In the BIRTH-DEATH mode the Fading Simulator simulates the dynamic propagation conditions according
to test case 3GPP, 25.104-320, Annex B4.
To do this, 2 paths are simulated which alternately appear (BIRTH) or disappear (DEATH) at random time
positions. The time positions lie within a grid of [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5]
µ
s. After a presettable time
(HOPPING DWELL) a path disappears from a grid position and re-appears at another randomly
selected grid position. During this hop, the second path remains stable at its grid position. After a further
HOPPING DWELL has elapsed, the second path changes its position and the first path remains at its
position, etc. The two paths never appear at the same time position (see Fig. 2-44).
According to Annex B4, each path has the same attenuation and phase and no Doppler shift. However,
this can be set in the menu BIRTH-DEATH for further tests. The dwell period of 191 ms (in line with
3GPP) can be varied between 100 ms and 5 s.
0 1 2 3 4 5
-1
-2
-3
-4
-5
0 1 2 3 4 5
-1
-2
-3
-4
-5
0 1 2 3 4 5
-1
-2
-3
-4
-5
P1
P2
P1
P1
P2
P1
P2
P2
Fig. 2-44
Example of hop sequence with BIRTH-DEATH fading
Fig. 2-45
Menu BIRTH-DEATH
STATE
Activation/deactivation of the BIRTH-DEATH simulation.
IEC/IEEE-bus command
:SOUR:FSIM:BIRT:STAT ON | OFF
IGNORE RF
CHANGES < 5%
When switched on, frequency variations below 5% are ignored. RF hopping is
thus faster than 3 ms. IEC/IEEE-bus command
:SOUR:FSIM:IGN:RFCH ON
STANDARD
Is now the same as SET DEFAULT.
SPEED UNIT
Selection of the unit required for the speed of parameter SPEED.
IEC/IEEE-bus command
:SOUR:FSIM:BIRT:SPE:UNIT KMPH