Digital Bus Information

Digital Bus Information

Last updated: November 10, 2006

This section is only applicable to the lab application with rear panel digital bus.

Description

A test set equipped with cdma2000, 1xEV-DO or W-CDMA lab applications can perform mobile station tests that require faded signals. The test set must be equipped with a rear panel that includes a connector labeled Digital Bus.

   
NOTE
For detailed setup and operating instructions pertaining to faded signal generation, refer to

E5515C Fading Solution Application Guide

It can be downloaded at http://cp.literature.keysight.com/litweb/pdf/1000-1894.pdf .

   

When a faded signal from the test set is needed, the forward baseband signal path from the Test Set is diverted to a PC running Baseband Studio software. This software is capable of digitally adding fading patterns requested by the user.

Fader Setup

Baseband Studio software also controls the test set's call parameters and digital bus signal path switching modes. The status of the various digital bus parameters and the controls themselves are made available by selecting Digital Bus Info from the Call Control screen.

  • Baseband Studio Summary - The current values in use for baseband signal level adjustments.
  • Digital Bus Summary - The current data and clock rates for the modulation type of the faded signal.

With the Digital Bus Information screen displayed, the following fading parameters are displayed:

The Bbio Control menu provides three settings:

  • Digital Bus Path - Must be Internal for non-faded signal operation.

  • ALC Mode - Must be Closed Loop for non-faded signal operation.

  • Calibrate Open Loop ALC - Used to generate calibration tables that are needed when ALC Mode is Open Loop.

   
IMPORTANT
The Digital Bus Path and ALC Mode fields are controlled by the Baseband Studio software when a faded signal is generated by the test set. The only time these field settings will need to be manually changed is during certain diagnostic routines. Refer to the Installation Note (E5515-90243) shipped with the Option 504 kit for instructions on performing diagnostic tests.