These tests are used to determine the performance of the transmitter and require the use of only one signal. The interferer signal is applied to the transmitter port.The tests are used do to determine a range of attributes such as power adjustment capability in the presence of an interferer, and the ability to inhibit undesired signals due to intermodulation. The tests are supported on only the N5172B EXG or the N5182B MXG signal generators.
A separate signal generator is required for each test signal. None of the signals can be combined into a single waveform file.
A few of the tests require the use of a GMSK Interferer signal. This software includes the ability to build this signal, so no additional Signal Studio software is required beyond that shown in the System Requirements topic.
To perform BER testing, a wanted signal with 1022 frames is required. This means that the wanted signal needs approximately 39 Msa of memory and can take about seven minutes to download depending on items such as processor speed and connection. An example of this is the wanted signal (RMC 12.2K) used for the 7.6 Intermodulation test. Because it can take time to download a test signal, the software has incorporated additional Execute behavior to minimize the time when changes are made to the signal.
With the PXB, the PXB controls the signal generators based on input from the software. The PXB generates the signals, then using the PXB configuration set in the PXB Setting window, outputs the signals to the signal generators for upconverting. Because the PXB controls the signal generators, the Signal Generator fields in the test setting window are grayed out. Use the PXB to add fading to any of the test signals.
The narrowband Clause 7 tests, Narrow Band Blocking and Intermodulation (Narrowband), use a GMSK Interferer signal. The software creates this signal differently form the W-CDMA signals in that the GMSK signal is created from a previously generated and stored waveform file. The W-CDMA signal is generated in conjunction with the N7600B Signal Studio software, there is no pregenerated waveform file. If a test includes the GMSK signal and the test settings are exported for use in the Signal Studio software, the GMSK settings, because of the pregenerated file, are not included in the exported file. In addition, the Signal Studio software cannot reproduce the GMSK signal.
If there is a need to continue using the GMSK Interferer provided by the software and it has already been download using this software, the signal can be controlled using the SCPI commands from the SCPI Log Viewer. If the GMSK waveform needs to be stored on the signal generator or manually download, see the Transferring the GMSK Interferer File topic.
Because some of these tests require fading or diversity output (multiple antennas), the instruments used require fading capability as well as single-user MIMO 1x2 operation. The software provides two selections for these capabilities. Either selection still requires the use of signal generators listed in the requirements topic. But how these signal generators are controlled for the signals is dependent upon the Fading Simulator selection, PXB, or External Fader.
With the PXB, the PXB controls the signal generators based on input from the software. The PXB generates the baseband signals and adds the AWGN. Then using the PXB configuration set in the PXB Setting window, outputs the signals to the signal generators for upconverting. Because the PXB controls the signal generators, the Signal Generator fields in the test setting window are grayed out.
With the external fader, a signal generator selection is required. The signal generator must be configured and show as connected in the Hardware Connections and Settings node. The software then controls, and downloads the signal and settings to the signal generator.