JDS Uniphase CellAdvisor JD780A Series, Руководство пользователя

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JD780A Series Analyzers
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Using Mobile WiMAX Signal Analyzer
Conducting modulation measurements
Constellation
The Constellation is used to observe some aspects of modulation accuracy and can reveal certain
fault mechanisms such as I/Q amplitude imbalance or quadrature imbalance. It displays constellation
diagram by modulation types.
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.
d. Enter a value by using the numeric keys, and then press the Enter soft key.
e. Press the CP Ratio soft key, and then select the cyclic prefix ratio option: 1/4 , 1/8 , 1/16 , or
1/32 .
f. Press the DL Symbols soft key to set the number of downlink symbols.
g. Enter a value by using the numeric keys, and then press the Enter soft key.
h. Press the UL Symbols soft key to set the number of uplink symbols.
i. Enter a value by using the numeric keys, and then press the Enter soft key.
3.
To set the start/stop symbols, complete the following steps:
a. Press the Start/Stop Symbol soft key.
b. Enter a value by using the numeric keys, and then press the Enter soft key.
4.
Toggle the Preamble Index soft key and select the preamble search method: Auto or Manual .
5.
Toggle the Search Type soft key and select Full or Window .
6.
Optional . Press the Miscellaneous soft key, and then do the following as needed:
–
To select the detect mode, press the Detect Mode soft key and then select the option:
Auto , QPSK , 16 QAM , or 64 QAM .
–
To select the downlink zone, press the DL Zone soft key and then select the permutation
zone option: Auto , PUSC for partial usage of subcarrier channels, FUSC for full usage of
subcarrier channels, or AMC2X3 for adaptive modulation and coding.