How Do I Make a Phase and Frequency Error Measurement?

How Do I Make a Phase and Frequency Error Measurement?

Last updated: March 17, 2009

Measuring 3GPP TS 51.010 Section 13.1 Phase and Frequency Error

This procedure assumes that the BCH parameter for Cell Band is set up correctly for your mobile station and that the appropriate RF IN/OUT Amplitude Offsets have been set to offset loss between the mobile station and the test set. For more details see How Do I Configure the Test Set for My Test System? .

  1. Connect the mobile.
  2. Turn the mobile on and wait for Attached in the Active Cell field located in the bottom center of the screen. Note: For mobiles that don't perform a GPRS attach automatically, set the mobile to data mode.

  3. Press the Start Data Connection ( F3 ) key and watch for the Active Cell field changing to Transferring .
  4. Press the Measurement selection key.
  5. Select the Phase & Frequency Error measurement.
  6. Press the Phase & Freq. Setup ( F1 ) key.
  7. Set the measurement parameters as needed for your measurement situation, including:
    Measurement Timeout = 10 s
  8. Verify that the RMS phase error is not greater than 5 degrees, and the peak phase error is not greater than 20 degrees. Also verify that the mobile station's carrier frequency is accurate to within 0.1 ppm. PCS was the Cell Band used while capturing the results below. For the PCS band the Frequency error should not exceed +/- 195.26 Hz.

    A typical phase and frequency error measurement result is shown above.

  9. Press the Change View ( F2 ) key.
  10. Press the Graph ( F2 ) key to access the peak phase error graph.

    A typical peak phase error graph is shown above. The bottom section of the graph displays the binary representation of the demodulated bits from the burst the measurement was made on, normal symbols are shown in white, midable symbols in yellow, midamble symbols in error in red and tail symbols in dark cyan (the midamble symbols and tail symbols are not shown in above picture due to some reasons, but actually you can see in the test set)

    The marker can be turned on by pressing the Graph Control ( F5 ) key then the Marker Position ( F2 ) key. Set the required marker position using the knob or the numeric entry keys. In addition, the axis values can be changed by pressing the Axis Control ( F1 ) key. This allows you to zoom in or out to look at particular sections of the graph in more detail.

    A typical peak phase error graph is shown above. This graph is zoomed in to show bits ranging from 100.0 to 120.0 at a 1.0 degrees per division setting. The Y-axis reference point is changed to 5.0 degrees.

    In this case, the marker is turned on and positioned at bit 104. The phase error at the marker and its bit position are shown at the top of the display above the graph.

    If you require details on how to navigate through the phase and frequency error graph menus, see Phase and Frequency Error Graph Menus .

Phase and Frequency Error Graph Menus

Related Topics


Phase and Frequency Error Measurement Description

Programming a Phase and Frequency Error Measurement

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Phase and Frequency Error Troubleshooting