Editing a Scenario

This procedure guides you through the settings to edit a scenario using the Scenario Generator tab on the software user interface (UI). To learn more about individual cell settings, refer to the UI descriptions.

To view a list of the completed edits through the UI, see the log at the bottom of the view in the Scenario Graphics tab.

1. Load a PXB GNSS configuration:

   If you already have a GNSS configuration loaded on the PXB, skip the following substeps and proceed to Step 2.

   1. Open the PXB Baseband Generator and Channel Emulator software.

   2. Under Generate in the Configuration Browser, select either a single- or dual-channel configuration.

   3. For each of the channels in the block diagram, click the drop-down arrow in the waveform block, and in the dialog box that appears, use the drop-down menu to select GNSS (Global Navigation Satellite System). ARB on the waveform block changes to GNSS.

      

   4. In the Assign Waveform Source dialog box, click OK.

   5. Assign an MXG/EXG/ESG signal generator to the output block for each channel along with selecting the IO Port and IO Port Type.

      

   6. In the Assign External Instrument dialog box, click OK.

   7. Click Load Configuration.

2. In the Settings Browser, select Scenario Generator and ensure the Scenario Generator tab is active, if not, select it.

   Notice that the software starts with Create as the default Generation Mode.

3. Click Generation Mode, and from the drop down menu, select Edit.

4. Click the Source Scenario File cell, and use the dialog box button to launch the Open dialog box for navigating to and selecting the scenario file to edit.

5. If there is a desire to keep track of the edits, click the Save Edit Log cell, and from the drop down menu, select  On.

   The software saves the log file with the same name (uses .log extension) and at the same location as the edited scenario file when you click the Save Scenario button.

6. Click Edit Mode and from the drop down menu, select the mode:

   • Delete Channel

   • Apply Power Offset

   • Equalize Power

   • Create Multipath

   • Trim

     The settings that follow the Edit Mode cell change based on this cell's selection.

7. Finish configuring the settings for the selected Edit Mode:

   • To Delete Channel

     

     To view active and deleted channels, click the Scenario Graphics tab.

     1. Click Source Channel, and enter the channel to delete.

     2. Click the Apply button.

     3. Repeat Steps a and b to delete another channel.

   • To Apply Power Offset

     

     1. Click Source Channel and set the channel to which the offset applies.

        If an offset was set in the original file, this offset is added to the original offset.

     2. Click the Start Time cell and enter the time location within the scenario where the power offset begins.

     3. Click the Stop Time cell and enter the time location within the scenario where the power offset stops.

     4. Click Power Offset, and enter the amount of the offset that occurs from the Start time value to the Stop time value.

     5. Click the Apply button.

     6. Repeat Steps a–e for applying additional power offsets.

   • To Equalize Power

     

     All of the satellite power settings in the scenario are relative to each other, so when you equalize the power, it sets all of the satellites to 0 dB. The actual output power is determined by the signal generator's amplitude setting.

     • Click the Apply button.

   • To Create Multipath

     

     1. Click Source Channel and enter the index of the satellite channel that is to receive the create multipath operation.

     2. Click Destination Channel and enter the index of the channel that will store the newly created multipath channel data.

     3. Click the Start Time cell and enter the time location within the scenario where the create multipath operation begins.

     4. Click the Stop Time cell and enter the time location within the scenario where the create multipath operation ends.

     5. Click Power Offset, and enter the amount of the offset that occurs from the Start time value to the Stop time value.

     6. Click Delay Offset, and enter the time delay of the multipath channel in chips.

     7. Click Doppler Shift, and enter the Doppler shift of the multipath channel in Hz.

     8. Click the Apply button.

   • To Trim

     

     1. Click the Start Time cell and enter the start time location within the scenario that marks the new start time location.

        For all channels, the software deletes the portion of the scenario with a time that is earlier than the value entered.

     2. Click the Stop Time cell and enter the stop time location within the scenario that marks the new stop time location.

        For all channels, the software deletes the portion of the scenario with a time that is later than the value entered.

     3. Click the Apply button.

8. To make further edits using another mode, repeat Steps 10 and 11.

9. When all changes have been made, click the Save Scenario button to launch the Save As dialog box for selecting a location and saving the file.

Related Topics

Scenario Generator