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WCDMA PRACH Measurement
R&S
®
CMW-KG4xx/-KM4xx/-KS4xx
854 User Manual 1173.9657.02 ─ 11
Fig. 5-6: Off power limit
5.2.6.5 Power Step Limits
During a random access procedure the UE is expected to transmit RACH preambles at
increasing power until the Node B sends an ACK on the AICH or until the maximum
number of preambles within one cycle is exceeded.
In the configuration dialog you can specify the expected step size and a symmetrical
tolerance value. The limit applies to all preamble steps. Exception: If the preamble
power exceeds the nominal maximum power plus the lower limit (see
chapter 5.2.6.2,
"Maximum Output Power Limits" , on page 852), no limit check is applied to the related
steps.
When the combined signal path scenario is active, the expected step size parameter
("Preamble Power Steps") is controlled by the signaling application.
The expected step size "Preamble Power Steps" is also used to calculate the expected
preamble power and to adapt the expected nominal power internally during the pream-
ble cycle.
Please note that 3GPP TS 34.121 specifies no test requirement for the accuracy of the
preamble power step size. But the minimum requirements section 5.5.2 "Transmit
ON/OFF Time Mask" contains a reference to 3GPP TS 25.101, section 6.5.2.1 and a
table of power step size tolerances.
Fig. 5-7: Power step limits
5.2.7 Measurement Results
The results of the WCDMA PRACH measurement are displayed in several different
views. Use the "Display" parameters to select the views and to change the appearance
and contents of the views. The views are described in the following sections.
● Overview ............................................................................................................... 855
● Detailed Views: Modulation ...................................................................................855
● Detailed Views: I/Q Constellation Diagram ........................................................... 856
● Detailed Views: UE Power and Power Steps ........................................................857
● Detailed Views: TX Measurement .........................................................................858
● Selecting and Modifying Views ............................................................................. 859
● Using Markers .......................................................................................................860
General Description
深圳德标仪器
135-1095-0799