In an effort to make your experience with the PXB as successful and effortless as possible, a variety of tips are listed below. A quick review of these tips prior to using the PXB will help with your success.
You must have the 10 MHz reference connected between external instruments and the PXB. Otherwise, you risk data underflow/overflow, which yields sub-optimal results.
Make sure the PXB reference is correctly set to internal or external for your setup.
The PXB currently supports the following
8960 Wireless Communications Test Set applications:
|
Model |
Description |
8960 Firmware Version |
PXB Firmware Version |
|
E1962B* |
cdma2000 Mobile Test App |
B.19.07 or later |
1.6.0 or later |
|
E1966A* |
1xEV-DO Terminal Test App |
A.13.10 or later |
1.6.0 or later |
|
E1987A* |
Fast Switch Test App Supports:
|
A.13.07 or later |
1.6.0 or later |
|
E6701G |
GSM/GPRS Lab App G |
G.01.12 or later |
1.6.0 or later |
|
E6702C |
cdma2000 Lab App C |
E.00.05 or later |
1.6.0 or later |
|
E6703C |
W-CDMA Lab App C |
C.01.17 or later |
1.5.3 or later |
|
E6706C |
1xEV-DO Lab App C |
E.00.05 or later |
1.6.0 or later |
|
E6785G |
Fast Switch Lab App G Supports:
|
G.00.15 or later |
1.6.0 or later |
|
E6785H |
Fast Switch Lab App H Supports:
|
H.00.06 or later |
1.6.0 or later |
|
E6703H |
DC-HSPA Support |
H.01.12 or later |
2.0.0 or later |
|
E6785H |
DC-HSPA Support |
H.01.13 or later |
2.0.0 or later |
* Requires the 8960 test application's corresponding Option 405 digital bus software license (E1962B-405, E1966A-405). The E1987A Fast Switch Test App requires the corresponding Option 405 license to use a desired format.
Before setting up a measurement using an 8960, go to http://wireless.agilent.com/rfcomms/refdocs and read the user's guide for the appropriate 8960 application.
If mobile station testing is performed at frequencies that do not have amplitude offsets assigned to them, the test set will estimate an amplitude offset based on the nearest settings. This can cause unexpected results in your measurements. The recommended approach is to clear all entries in the 8960's RF IN/OUT Amplitude Offset table to prevent any undesired amplitude offsets. If you want to use the 8960's Amplitude Offset feature, make sure you fully understand its operation before setting up a measurement. For detailed information on Amplitude Offset for 8960 applications, go to http://wireless.agilent.com/rfcomms/refdocs and read the Amplitude Offset topic under Measurements for your desired application.
In all supported configurations using the 8960, if the signal power and noise power differ by more that 20 dB during power calibration, the 8960 will generate an error due to the limitations its hardware.However, in 1x2 configurations, since the RF signal is sourced from the signal generators, the error messages can be safely ignored. Alternately, you can manually set the 8960 cell power to match the signal power shown on the AWGN Settings of the PXB. If AWGN is not used, set the cell power to match the amplitude of the signal generators.
The PXB's AUX I/O port provides connectivity to external devices for auxiliary signaling information, such as output markers (frame, even second, etc.) or input signals from a device under test (power control commands, HARQ, ACK/NACK, etc.). AUX I/O port functionality is controlled through two groups of settings: global PXB settings (see Global AUX I/O Settings) and application settings (see AUX IO Summary). See the Signal Studio application's help for specific signal pin assignments.
Many of the connectors on the PXB I/O cards are SMB. You'll need one to four SMB to BNC cables (Agilent part number 8121-1789) or adapters depending on your setup (differential analog I/Q output setups and markers require more SMB to BNC cables or adapters).
Make sure the digital bus cables (Agilent part number N5101-60003) are correctly connected between the external instruments and the PXB.
Verify that the digital bus cable connectors are securely locked on both sides and at both ends.
Make sure the external instruments have the correct firmware revisions and the correct options installed.
|
|
For best performance, external instruments connected to PXB should have the same options and the same firmware revision. Mixing different models of analyzer or source, mixing options within those products, or mixing firmware revisions within those products will cause small latency differences between the channels. This can lead to unexpected degradations in the measurement's results. |
| Baseband generator option (E4438C-601 or E4438C-602) |
High output power option recommended
(N5182A-1EA)
|
|
For best performance, external instruments connected to PXB should have the same options and the same firmware revision. Mixing different models of analyzer or source, mixing options within those products, or mixing firmware revisions within those products will cause small latency differences between the channels. This can lead to unexpected degradations in the measurement's results. |
|
|
For external input, the PXB supports signal analyzers at a maximum bandwidth of 40 MHz with Option RTL and (B1X or B40). |
|
|
Signal analyzers that are used in 2x8 MIMO (ext in) configurations are required to have Option RTL for corrected IQ data (DIF 40 hardware) installed. |
| 25 MHz analysis bandwidth option: N9030A-B25 | |
| 40 MHz analysis bandwidth option: N9030A-B40 | |
| 140 MHz analysis bandwidth N9030A-B1X |
| 25 MHz analysis bandwidth option: N9020A-B25 | |
| 40 MHz analysis bandwidth option: N9020A-B40 |
| 25 MHz analysis bandwidth option: N9010A-B25 | |
| 40 MHz analysis bandwidth option: N9010A-B40 |
| Basic VSA option: 89601A-200 (required) | |
| Hardware connectivity option: 89601A-300 (required) |
The external instruments must be in a known state when the PXB is controlling them.
Before starting, preset the external instruments.
Make the external instrument settings from the PXB user interface, not from the external instrument front panel.
Check that the carrier frequency in Fader Master Setup matches the carrier frequency of the RF source when using the fader.
These parameters are not automatically coupled and will cause Doppler errors if they are different.
When installing I/O boards in a PXB, make sure to install them starting with the IOA slot (the first, or top slot), leaving unoccupied slots at the bottom of the unit. The PXB will not recognize I/O boards and will fail to properly load configurations, especially if the IOA slot is left empty.
Make sure the LAN or GPIB connection to the external instruments is working.
It is important to note that the GPIB port must be either an input or an output. Therefore, you cannot control the PXB through a GPIB input, and then concurrently use the PXB to control an MXA or an MXG through the GPIB output. There are multiple ways that allow the PXB to be a listener and a talker concurrently:
Use LAN for all instruments, so that this problem never arises.
Use the PXB as the controller, so that the GPIB port is only an output. If you use the PXB as a GPIB controller, be sure to enable the interface in Agilent IO libraries. The PXB defaults to a slave instrument.
Use mixed modes: LAN to PXB, then GPIB from PXB to external instruments.
Use GPIB as the input to PXB, then a USB-to-GPIB converter to connect the PXB to external instruments.
Set all the output signal generators to the same power, the power of the highest signal in the group.
The PXB provides power balancing between antennas so that the output power will be correct when measured with a power meter.
Latency compensation is performed such that combinations of X-Series Signal Generators (MXG-A, MXG-B, EXG-B) are now supported for both SISO and MIMO configurations. Combinations of X-Series Signal Generators and the ESG-C are not allowed in MIMO configurations. ESG-C is allowed in combination with X-Series Signal Generators for SISO configurations only and latency compensation is performed.
For signal analyzers, the dependency is on the installed options rather than model number. For MIMO configurations, PXA/MXA/EXAs with RTL can be mixed and PXA/MXA/EXAs without RTL can be mixed, but the instruments must all either have RTL or not. Signal Analyzers used in MIMO configurations should be running the same firmware version for best performance. For non-MIMO configurations, the PXB allows mixing but warns the user about the different latencies.
You must set the attenuator to maximize dynamic range.
Do not let the input power to multiple MXAs be widely different. A 20 dB difference is OK; a 50 dB difference is not because both are using the same settings and they do not have that much dynamic range in the digitizer.
In general, the PXB works best with the ALC turned off in the signal generators.
Having the ALC turned on only works when channel summing, noise, and fading are turned off.
If you must turn the ALC on, you will have to route the markers manually in the signal generator user interface.
You must run a user IQ calibration on the MXG or ESG to minimize LO feedthrough.
It is possible for the RMS of the signal to get so low due to the backoff required for Peak to Average Ratio of fading and noise, that LO feedthrough becomes a significant contributor to EVM and output power.
A good I/Q calibration is critical to making accurate measurements.
When you think the PXB is playing, check for the DIGBUS annunciator on the front panel of the ESG or MXG. If the annunciator is not displayed, one of the following is probably the issue:
The digital bus cable is not present or is not connected correctly.
The waveform is not actually playing.
The waveform output is directed at the wrong I/O port.
The incorrect firmware revision is installed in the signal generator.
Make sure you have the correct C19 AC power cord. PXB power cords are unique on the PXB end.
There are two PXB executable icons on the desktop - one indicates simulation mode and the other uses real hardware.
Use the mode that exercises the hardware (does not have "Simulation Mode" in its name).
When the PXB powers up, it auto-starts the PXB firmware.
To install licenses on the PXB, run the Agilent License Manager (ALM) from within the PXB.
If you have a USB memory device with a PXB license file saved on it, the PXB will not automatically install the license.
If you encounter an unexpected error, do as instructed by the firmware.
Save the N5106A and InternalN5106A event logs:
Select Start > Control Panel > Administrative Tools > Event Viewer
Open the event log for N5106A, choose Action, and select "Save Log File As" to save the file
Repeat step b for the InternalN5106A event log
Report the problem to your Agilent representative with as much detail as possible when describing what was being done when the problem occurred.
PXB firmware version 1.9 and later includes Revision to Current (R2C) licensing. Under R2C licensing, new features and enhancements are enabled on the instrument with a purchased and installed N5106AK-R2C upgrade license. Bug fixes are not considered enhancements and do not require an R2C license. See the Release Notes or www.agilent.com/find/N5106AK-R2C for more information.
PXB errors (e.g., "not connected to MXG") and crashing can occur during power calibration if the test system's RF network feeds reverse power into an MXG's output ports. Reverse power levels of as little as -50 dBm can cause problems. To prevent reverse power problems, use a circulator or similar to block downlink signals.
The .bin files saved during signal capture operations are unencrypted and can be used with any Agilent signal generators for playback, including the PXB. You can later analyze signals captured and saved as .bin files using the VSA software, but it requires byte swapping. You can also import them into Matlab; however, the files require some reformatting. See Understanding Binary Formatted Waveform Data for information on the supported I/Q waveform format.
With the firmware license Option N5106AK-169, Fader Interleaving for 4x4 and 2x8, the number of DSP units can be extended for larger MIMO configurations and up to four fader channels per baseband board. MIMO configurations that require this option are shown in the Configuration Tree with asterisks.
If you want to use the touch screen, there is a Windows keypad for entering units. To open the keypad:
Select On-Screen Keyboard from the Tools menu.
With the PXB application as the active window, press the Keyboard hardkey on the front panel.
