How Do I Use the Real-Time Vocoder?

How Do I Use the Real-Time Vocoder?

Last updated: October 26, 2010

This section is only applicable to the lab applications and the test application with a required feature license.

The following procedure provides an example usage of Real-Time Vocoder. It is assumed that a mobile station's antenna output is connected to the test set's RF IN/OUT connector, an external audio source (such as a microphone) is connected to the test set's AUDIO IN port, and an external audio receiver (such as a loudspeaker) is connected to the test set's AUDIO OUT port.

General Procedure

  1. Press the blue SHIFT key and then the green Preset key to fully reset the test set.
  2. Follow the procedure described in How Do I Set Up a Call and Make a Connection? to establish a voice call.
  3. Press the lower left More key until menu 3 of 6 of Call Control is displayed.
  4. Press Voice Call ( F5 ), and then AMR Setup ( F1 ).
  5. Set AMR Source to Real-Time Vocoder from the pop-up menu.
  6. Press Real-Time Vocoder Parms ( F3 ). The Real-Time Vocoder Parameters menu is displayed. Set the parameters as desired and then press the close menu ( F6 ) key when finished.
  7. Speak into the mobile station. Verify that the voice is heard from the loudspeaker. The voice encoded by the mobile station is sent to the test set over the RF link. The test set then demodulates, decodes the signal and converts it to an analog signal output to the AUDIO OUT connector. The signal is then played by the loudspeaker.
  8. Speak over the microphone (that is connected to AUDIO IN connector). The analog voice signal is input to the test set's AUDIO IN connector. The test set samples, encodes the signal, and modulates it onto the RF link. When the mobile station receives the RF signal, it demodulates, decodes, and converts the signal into an analog audio output to its speaker. Verify that the voice is heard from the mobile station's speaker.
  9. A typical display during real-time vocoder operation is shown below. For an explanation of the encoder headroom and decoder headroom results, see Real-Time Vocoder Headroom Information .

Related Topics

Real-Time Vocoder

CALL:RTVocoder