Operating Manual Vol 1 - ES Documentation

SMIQFading Simulation2.9.4.4 Menu BIRTH-DEATHIn the BIRTH-DEATH mode the Fading Simulator simulates the dynamic propagation conditions accordingto test case 3GPP, 25.104-320, Annex B4.To do this, 2 paths are simulated which alternately appear (BIRTH) or disappear (DEATH) at random timepositions. The time positions lie within a grid of [-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5] µs. After a presettable time(HOPPING DWELL) a path disappears from a grid position and re-appears at another randomlyselected grid position. During this hop, the second path remains stable at its grid position. After a furtherHOPPING DWELL has elapsed, the second path changes its position and the first path remains at itsposition, 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 with3GPP) can be varied between 100 ms and 5 s.P1 P2 P1 P1 P2 P2 P1P2-5 -4 -3 -2 -1 0 1 2 3 4 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 -5 -4 -3 -2 -1 0 1 2 3 4 5Fig. 2-44Example of hop sequence with BIRTH-DEATH fadingFig. 2-45STATEMenu BIRTH-DEATHActivation/deactivation of the BIRTH-DEATH simulation.IEC/IEEE-bus command :SOUR:FSIM:BIRT:STAT ON | OFFIGNORE RFCHANGES < 5%STANDARDSPEED UNITWhen switched on, frequency variations below 5% are ignored. RF hopping isthus faster than 3 ms. IEC/IEEE-bus command :SOUR:FSIM:IGN:RFCH ONIs now the same as SET DEFAULT.Selection of the unit required for the speed of parameter SPEED.IEC/IEEE-bus command :SOUR:FSIM:BIRT:SPE:UNIT KMPH1125.5555.03 2.83 E-9