LTE PRACH Measurement
R&S
®
CMW-KM5xx/-KS5xx
741
User Manual 1173.9628.02 ─ 16
4.2.1 Test Setup
The external RF signal source (mobile station, signal generator etc.) is connected to
one of the RF input connectors (RF COM) at the front panel of the R&S
CMW. No
additional cabling and no external trigger is needed.
The input level ranges of all RF COM connectors are identical.
See also: "RF Connectors" in the R&S
CMW user manual, chapter "Getting Started"
Fig. 4-1: Connecting an RF transmitter to the instrument
4.2.2 How to Measure an Uplink PRACH Signal
The measurement expects an LTE PRACH UL signal. Any other signals, e.g. an LTE
UL signal without preambles (established connection) will not yield measurement
results.
After connecting your LTE UE to the R&S
CMW, you have to adjust at least the follow-
ing analyzer settings to the properties of the analyzed PRACH signal:
●
Duplex mode
●
Analyzer "Frequency"
●
"Expected Nominal Power", (optional) "User Margin" and "External Attenuation
(Input)".
Recommended values: "Expected Nominal Power" = peak power of the UE signal
during the measurement; "User Margin" = 0 dB. The smallest possible value of the
"Expected Nominal Power" plus the "User Margin" ensures maximum dynamic
range.
A number of "Measurement Control" settings in the configuration dialog must be in
accordance with the measured signal, the transmitted preambles and especially the
used Zadoff-Chu sequence. This is required for synchronization to the received signal
and proper decoding. Ensure that the following parameters match up:
●
"Channel Bandwidth"
●
"PRACH Configuration Index"
●
"High Speed Flag": this software version supports only the value FALSE, i.e. the
unrestricted set of N
CS
must be used
●
"Logical Root Sequence Index"
●
"Zero Correlation Zone Config"
General Description
深圳德标仪器
135-1095-0799
