Example Usage of Reverse CLPC Transient Mode

 Last updated: October 28, 2004

 You can use an external spectrum analyzer or the test set's internal Spectrum Monitor to observe the mobile station's response to the closed loop power control (CLPC).

 

 Testing 4.4.4 Range of Closed Loop Power Control

 Definition: The mobile station provides a closed loop adjustment to its open loop estimate. Adjustments are made in response to valid received power control bits. The range of the adjustment is defined by the difference between the maximum mobile station output power and the open loop estimate, and the difference between the minimum mobile station output power and the open loop estimate.

 We recommend you use the test set and an external Spectrum Analyzer (for example, Keysight E4443A PSA) to make the tests. The general setup procedure is shown below. You may need to change some settings that are appropriate for your test scenario.

  1.  
  2. Hardware Connection:
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    • Connect the mobile station's antenna output to the power splitter; Connect one output end of the power splitter to the RF INPUT port of the PSA; Connect the other output end of the power splitter to the RF IN/OUT port on the test set's front panel.
    •  Connect the TRIG OUT port on the test set's rear panel to the EXT TRIGGER INPUT port on the PSA's front panel via a BNC cable.
    •  Connect the 10 MHz REF IN port on the test set's rear panel to the 10 MHz OUT (SWITCHED) port on the PSA's rear panel via a BNC cable.
  3.  Press the blue SHIFT and then the green Preset key to full reset the test set.
  4.  Establish a call with the following parameter settings (you need to change some settings as needed).
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    • Press CALL SETUP to access Call Parms and Call Control menus.
    •  Set Cell Band ( F8 on the Call Parms 1 of 4 ) to US PCS or others depending upon your mobile station.
    •  Set Radio Config ( F11 on the Call Parms 1 of 4 ) to (Fwd1, Rvs1) .
    •  Select FCH Service Option Setup ( F12 ) (Call Parms 1 of 4) , set Service Option for Fwd1, Rvs1 to SO2 (Loopback) .
    •  Set Traffic Data Rate ( F12 on the Call Parms 2 of 4 ) to Full (indicating 9600 kbps), or other values required for your tests (Half indicating 4800 kbps, Quarter indicating 2400 kbps, Eighth indicating 1200 kbps).
    •  Press Originate Call ( F3 ) to initiate a call. Verify that the Connected is in the Active Cell status field.
  5.  Set Call Drop Timer to Off ( F10 on the Call Parms 2 of 4 menu) to keep the test set from drop the connection based on the very low output power level of the mobile station.
  6.  Set Cell Power (Î or ) to -61 dBm/1.23 MHz ( F7 on the Call Parms 1 of 4 ) to yield an open loop output power, measured at the mobile station antenna connector, of -15 dBm (for US PCS band). It is variable due to the selected cell band).
  7.  Set Pwr Ctrl Size ( F8 on the Call Parms 2 of 4 menu) to 1.0 dB power control step size. Change the setting as required for other tests.
  8.  Set Rvs Power Ctrl ( F7 on the Call Parms 2 of 4 menu) to Alternating bits , which makes test set to transmit consecutive alternating '0' and '1' power control bits to the mobile station.
  9.  Press the Rvs Power Ctrl Transient Parm ( F8 ) on the Call Parms 4 of 4 menu. See Setting Reverse CLPC Transient Parameters for details on the parameters.
    •  
    • Set the Transient Number of Steps to 100 .
    •  Set the Transient Mode to Up-Down-Up .
    •  Press the Close Menu ( F6 ) key.
  10.  Set External Trigger Type ( F4 on the Gen Info menu) to FDEPendent (see How Do I Change Generator Information? ). For more details on the trigger sources, see Setting External Trigger .
  11.  Set up the PSA: set its trigger source to use EXT FRONT (depending on your hardware connection); turn on the 10 MHz OUT timebase; set to use zero span mode, and set other parameters needed for your test scenario. See the PSA user's documents for details on the PSA setup.
  12.  Go to Call Parms 4 of 4 menu, press the Start Rvs Power Ctrl Transient ( F2 ) key to start sending the closed loop power control bits as specified in step 10. Note that coincident with the transmission of the first power control bit of the transient the test set will output a trigger signal (a TTL rise based pulse with a width of about 1.25 ms.) to the TRIG OUT port on the test set's rear panel as specified in step 9. After completion of the transient transmitting, the closed loop power control returns to the Alternating bits mode as specified in step 7. See Reverse CLPC Transient Modes for details.
  13.  Observe the measurement results from the PSA. A typical display is shown below.
  14.  Repeat the procedures and change the settings as required for other tests.
  15.  After finishing the measurements:
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    • Turn the Call Drop Timer back to On .
 

Related Topics
 

Setting Reverse Closed Loop Power Control

 Setting External Trigger

 How Do I Change Call Parameters?