Two measurement display modes are available: spectrum and spectrogram. Figure: CPRI Spectrum Display and Figure: CPRI Spectrogram Display show display screens on an Anritsu BTS Master MT8220T loaded with Option 752. The screens and menus on your instrument may differ depending on the model, installed option, and firmware version.
In both display modes, the connection status of the SFP ports is displayed on the instrument screen as colored dots above the sweep window. Green indicates a good connection, red indicates an error, and gray (no color) means no connection. In the examples below, a dual-port instrument model is shown and Port 2 has no connection.
• LOS – Loss of Signal
• LOF – Loss of Frame
• RAI – Remote Alarm Indication, returned to sender as a response to LOS or LOF
• SDI – SAP (Service Access Point) Defect Indication, when any of LOS, LOF, or RAI is detected
CPRI Spectrum
Spectrum mode displays signals as a waveform in a traditional spectrum analyzer view.
CPRI Spectrum Display
• AxC Group No – Shows the AxC group containing the IQ data represented by each of the potential four traces. The AxC group numbers are color-coded to match the display colors of Trace 1 through Trace 4. Use the AxC Trace Config Menu to manually select the AxC group number for each trace. (This multiple AxC group feature requires firmware version 2.6 or later.)
• Line Rate – Displays the selected line rate for SFP Port 1 (top) and Port 2 (bottom).
• Ref Lvl – Indicates the maximum amplitude value on the Y-axis, that is, the top grid line, of the sweep window. Refer to Amplitude Menu. The value shown is the amplitude reference level of the currently active display: Display 1 or Display 2.
• RBW – Is the current resolution bandwidth. When present, a pound sign (#) in front of RBW indicates that the Auto RBW setting is off and the RBW value is or can be set independently of the frequency span. Refer to Bandwidth Menu.
• VBW – Is the current video bandwidth. When present, a pound sign (#) in front of VBW indicates that the Auto VBW setting is off and the VBW value is or can be set independently of RBW.
• Display BW – Shows the CPRI bandwidth of the currently active display. Refer to Display Config Menu.
• Traces – Displays the Trace A, B, and C Operations settings associated with Trace 1. Refer to Trace Menu. These settings are not displayed when Trace 1 is turned off.
• AxC Display – Lists the traces (1 through 4) that are currently turned on. Refer to AxC Trace Config Menu.
• Sweep – Shows the current sweep mode, single or continuous. Refer to Sweep Menu.
Spectrogram
A spectrogram is a three-dimensional representation of frequency, time, and power. Color is used to represent the relative power levels.
CPRI Spectrogram Display
• Sweep Interval – Shows the sweep interval of the currently active trace. Refer to Spectrogram Menu.
• RBW – Is the current resolution bandwidth. When present, a pound sign (#) in front of RBW indicates that the Auto RBW setting is off and the RBW value is or can be set independently of the frequency span. Refer to Bandwidth Menu.
• VBW – Is the current video bandwidth. When present, a pound sign (#) in front of VBW indicates that the Auto VBW setting is off and the VBW value is or can be set independently of RBW.
• Traces – Displays the Trace A, B, and C Operations settings associated with Trace 1. Refer to Trace Menu. These settings are not displayed when Trace 1 is turned off.
• AxC Trace – Shows the number of the trace being displayed, N/A if no carrier trace is configured, that is, turned on. In dual display mode, a value is displayed for each of Spectrogram Display 1 and 2. When switching from dual to single mode, the currently active display will be shown as the single display. Refer to Display Setup Menu.
