The purpose of the State checkbox is to set the state of the signal generator RF output:
The behavior of the State checkbox varies depending on signal settings such as whether the signal is a multi-carrier signal using one or multiple instruments, or if AWGN is a signal component. But regardless of the State status, checked or unchecked, with each click of the Execute button, the software always downloads all of the carriers shown in the test settings window.
For the instruments supported by the software, the AWGN state can be checked (on) or unchecked (off). This provides the choice of either having the signals with or without AWGN.
When the wanted signal state is checked, the AWGN state can be checked or unchecked. If the wanted signal is unchecked, the current AWGN state remains and cannot be changed.
The AWGN state does not affect the RF output of the instrument, it merely turns the Dual ARB AWGN feature on or off.The wanted signal state determines the RF output state. For example, if the both the wanted signal and AWGN states are unchecked, when Execute is clicked, the software creates and downloads the signal with the following state settings:
With the PXB as the Signal Generator selection, the wanted signal state grays out and remains checked. The PXB generates the AWGN, and the AWGN checkbox can be checked or unchecked.
With the PXB as the Fading Simulator selection, the PXB generates the AWGN and the AWGN checkbox can be checked or unchecked.
With the External Fader as the Fading Simulator selection, the software AWGN Interferer checkbox and settings are unavailable and grayed out. The AWGN must be provided by the external fader, which is not controlled or supported by the software.
This section applies to only LTE and W-CDMA Clause 7 tests.
The software couples all of the carrier states to the wanted signal. This indicated by the grayed out State checkbox for all signals but the wanted signal. When the wanted signal state is unchecked, the software unchecks all of the State check boxes. When the wanted signal state is checked, all carrier states are checked. Regardless of the State checkbox status, when Execute is clicked, the software creates and downloads the waveform file with all of the carriers. The only change that occurs with regards to the State checkbox, is whether the instrument RF Output is on or off.
For guidance on combining signals, refer to the LTE FDD and LTE TDD Tests topic.
See the section, Multi-Carrier Signal using Multiple Instruments, PXB-LTE Clause 7 Tests.
The software couples the state of only those carriers that use the same instrument as selected in the Signal Generator field. For each carrier that uses a different instrument, the State status is independent for that signal.
This means that for each carrier that uses its own instrument, the RF output of that instrument can be toggled on or off independently of the other carriers by checking or unchecking the State check box. For example, if the test signal uses three carriers, a wanted signal, an interferer (E-UTRA, Interferer, W-CDMA, etc.), and a CW interferer, and each carrier uses a different instrument, the following instrument states would occur for the indicated software State status:
State is Checked
- Dual ARB or real-time application is on
- RF output is on
State is Unchecked
- Dual ARB or real-time application is on
- RF output is off
CW Interferer—State is Checked
- RF output is on
For tests where the CW Interferer uses its own instrument, the software does not create a waveform file so there is no need for the Dual ARB. Instead the software only sets the instrument settings for the CW signal. For more information, see the Waveform Files topic.
LTE Clause 7: E-UTRA Interferer and CW Interferer Combined—State is Unchecked
In this instance, the CW interferer state is coupled to the E-UTRA interferer state and cannot be independently set. So if the E-UTRA interferer state is unchecked, the software also unchecks the CW interferer state. If the E-UTRA interferer is checked, the CW interferer is also checked.
- Dual ARB is on
- RF output is off
When the CW Interferer uses the same instrument as one of the other carriers, it becomes part of the other carrier's waveform file. For more information, see the Waveform Files topic.
For guidance on whether signals can be combined, refer to the Test Case Manager Software topic.
While the PXB is a single instrument, it has the capability to use multiple baseband generators (BBG) and its use requires multiple instruments. Signal generators are connected to the PXB as RF upconvertors and controlled by the PXB based on the software settings. If it is a single channel configuration (one BBG—PXB (BBG1)), only one signal generator is needed.if it is a two channel configuration (two BBGs—PXB (BBG1/2), two signal generators are needed. When a signal uses the PXB selection of either PXB (BBG1) or PXB (BBG2) as the Signal Generator selection, the signal state grays out and remains checked. The override settings feature does not change this attribute.
With PXB as the Fading Simulator selection, the Signal Generator selection for each signal grays out along with the state checkbox. The override settings feature does not change this attribute. This is because the signal generators are connected to and controlled by the PXB based on the software settings. But the AWGN state checkbox is available to toggle on or off. When checked, the PXB generates the AWGN.