CDP Composite (cdma2000/1xEV-DV)
trace shows the measured channel power in each code channel for the composite signal. Code Domain Power (CDP) is an analysis of the distribution of signal power across the set of Code Channels normalized to the total signal power. When Normalize IQ Traces is on, the power is expressed in dBc deciBels referenced to the carrier: A technique for expressing a power measurement in logarithmic form using the carrier power as a reference., and is relative to the total power in the signal. When Normalize IQ Traces is off, the power is expressed in dBm deciBels referenced to a milliWatt: dB relative to 1 milliwatt dissipated in the nominal input impedance of the analyzer. If the is greater than one, all PCGs within the are averaged together to produce the CDP Composite results.
You can view CDP trace data as absolute power by clearing the check box ( tab).
Display Format
The data is shown in a multi-color format that assigns a unique color to each code layer and related active code channels. This makes it easy to visually identify and distinguish the active code channels () for a given code layer (). The colors are also user definable (see Display Preferences > Color tab).
For CDP and CDE trace data displays with separate I/Q channel trace bars, to position the Marker to the desired Code Layer/Channel bar, you must click in close proximity to the horizontal bar that indicates the value of the code channel being measured.
The y-axis shows the power level and the x-axis shows the (code channel). The x-axis annotation and marker location are based on the lowest symbol rate (ksym/sec), or equivalently, the highest . The channels can be reordered so that all related code channels are displayed adjacent to each other (see Code Order).
This example Channel 1 Composite CDP display (code order = bit reversed), Trace A Marker shows the following:
|
Symbol Rate: |
38.4 Ksym/s |
|
Walsh Code Length: |
32 |
|
Walsh Code Number |
18 |
|
Power Level: |
-9.714 dB |
|
Asterisk *: |
The asterisk (*) indicates that the marker is positioned on an active channel |
Use the CDP Layer trace data display to view only one code layer () at a time.
See Also
