Viavi CellAdvisor JD700B Series, Руководство пользователя

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Chapter 10 Using CDMA Signal Analyzer
358
JD700B Series User’s Guide
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Do one of the following:
To Select Trace Legend
Clear current data and display with new
measurements Clear Write W
Display the input signal’s maximum response only
(unlimited or for a certain amount of time) Max Hold M
Display the input signal’s minimum response only
(unlimited or for a certain amount of time) Min Hold m
Capture the selected trace and compare traces Capture C
Load a saved trace More (1/2) > Load L
Hide the displayed trace Trace View > Off F
Remove all the traces and initialize the trace
settings More (1/2) > Trace
Clear All
NOTE
For the Max Hold and Min Hold , your instrument compares newly acquired data with the
active trace and displays larger maximum values or smaller minimum values on the
screen. You can set it to
Unlimited to hold and view maximum or minimum data or
specify a certain amount of time up to 60 seconds by using numeric keys or rotary knob.
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To select the detection option, select More (1/2) > Detectors , and then do one of the following:
To display Select
Random noise better than the peak without missing signals Normal
The highest value in each data point Peak
The root mean squared average power across the spectrum RMS
The lowest value in each data point Negative Peak
The center value in each data point Sample
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Optional . Select More (1/2) > Trace Info , and then select the trace number to view the trace’s
parameter setting information stored at the time of the measurement or None to hide the
information display.
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Optional. If you have the two traces T1 and T2, you can perform trace math. To view the power
difference between the traces, press the T1 – T2 -> T5 or T2 – T1 -> T6 soft key.
The result is overlaid on the screen along with the second Y-axis.
Conducting RF measurements
Channel power
The Channel Power measurement is a common test used in the wireless industry to measure the total
transmitted power of a radio within a defined frequency channel. It acquires a number of points representing
the input signal in the time domain, transforms this information into the frequency domain using Fast Fourier
Transform (FFT), and then calculates the channel power. The effective resolution bandwidth of the frequency
domain trace is proportional to the number of points acquired for the FFT.
The channel power measurement identifies the total RF power, power spectral density (PSD) and peak to
average ratio (PAR) of the signal within the channel bandwidth (1.23 MHz for cdmaOne).
After configuring test parameters as described in the “Configuring test parameters” on page 352, your
measurement result is displayed on the screen as like the following example,
Figure 210 .