JDS Uniphase CellAdvisor JD780A Series, User Manual

Page: 477 / 592

JD780A Series Analyzers
Using Mobile WiMAX Signal Analyzer
477
Measurement example
Figure 238 EVM vs. subcarrier measurement with Mobile WiMAX signal analyzer
NOTE
You can use the LIMIT hot key to analyze your measurements with the user-definable
limit and Pass/Fail indication. See
“Setting limit for modulation tests” on page 479 for
more information. The Spectral Flatness and Frequency Error are not used in the EVM
vs. Subcarrier mode.
EVM vs. symbol
The EVM vs Symbol is used to show the error vector magnitude representing the average
constellation error of WiMAX OFDMA symbols.
Setting measure setup
After configuring test parameters as described in the
“Configuring test parameters” on page 456, you
can continue your measurement. The measurement settings can be saved and recalled as a file. You
can also use JDViewer, PC application software to configure a measure setup, save as a file, and load
the file on to the instrument.
Procedure
1.
Press the MEASURE SETUP hot key.
2.
Press the System Config soft key, and then do the following:
a. Press the Bandwidth soft key, and then select the nominal channel bandwidth to be
measured from the following choices:
–
7 MHz (8/7): Sets the channel bandwidth to 7 MHz with sampling factor 8/7. In
conjunction with nominal channel bandwidth
–
8.75 MHz (8/7): Sets the channel bandwidth to 8.75 MHz with sampling factor 8/7
–
10 MHz (28/25): Sets the channel bandwidth to 10 MHz with sampling factor 28/25
b. Toggle the Frame Length soft key and select 5 ms or 10 ms .
c. Press the TTG (RTG) soft key to set the transmit/receive transition gap between the last
sample of the downlink burst and the first sample of the subsequent uplink burst.