Programming a Block Error Measurement
Last updated: May 8, 2002
This measurement is
not
applicable to GSM.
This section provides an example of how to make the block error (BLER) measurement via GPIB.
The following procedure assumes that the Operating Mode has been set to Active Cell (using
CALL:OPERating:MODE
) and the data connection type has been set to ETSI Type B or BLER (using
CALL:FUNCtion:DATA:TYPE
). In addition, it is assumed that a data connection has been established between the test set and the mobile station (that is, the connection status is Transferring). See
Step 4: Make a connection
. Note that you can also make BLER measurements when the test set's operating mode is set to GPRS BCH+PDTCH test mode (see
CALL:OPERating:MODE
).
-
Configure the BCH and PDTCH parameters using the CALL subsystem.
-
Configure the Block Error measurement parameters using the SETup subsystem.
-
Configure the downlink PDTCH parameters using the CALL subsystem.
-
Start the Block Error measurement using the INITiate subsystem.
-
Use the FETCh? command to obtain Block Error measurement results.
Programming Example
10 ! This code assumes that the current data connection state is Transferring.
20 !
30 ! Configure BCH and PDTCH parameters.
40 OUTPUT 714;"CALL:POW -50 DBM" ! Set the BCH power.
50 OUTPUT 714;"CALL:PDTCH:PZER:LEV 30" ! Set the P0 reference level to 30 dB.
60 OUTPUT 714;"CALL:PDTCH:CSCH CS4" ! Set the channel coding scheme to CS4.
70 ! Configure the measurement parameters
80 OUTPUT 714;"SET:BLER:TIM:TIME 5" ! BLER measurement times out after
90 ! 5 seconds.
100 OUTPUT 714;"SET:BLER:CONT OFF" ! Configures a BLER measurement to
110 ! Single Trigger.
120 OUTPUT 714;"SET:BLER:COUN 2000" ! Sets the number of blocks to measure
130 ! at 2,000.
140 OUTPUT 714;"SET:BLER:LDC:AUTO ON" ! Sets the Loopback Delay
150 ! Control mode to ON. This
160 ! commands the test set to
170 ! determine the Block Delay.
180 ! Set up and select the downlink PDTCH power reduction levels.
190 OUTPUT 714;"CALL:PDTCH:PRED:LEV1 12db"
200 OUTPUT 714;"CALL:PDTCH:PRED:LEV2 0dB"
210 OUTPUT 714;"CALL:PDTCH:PRED:BURS1 PRL1"
220 OUTPUT 714;"CALL:PDTCH:PRED:BURS2 PRL1"
230 OUTPUT 714;"INIT:BLER" ! Start a BLER measurement.
240 REPEAT
250 OUTPUT 714;"INIT:DONE?"
260 ENTER 714;Meas_complete$
270 UNTIL Meas_complete$="BLER"
280 ! Fetch results.
290 OUTPUT 714;"FETC:BLER?"
300 ENTER 714;Integrity,Blocks_tested,Block_ratio,Block_err_cnt
310 END
Returned values
The measurements returned by this program are:
-
Integrity
returns the
Integrity Indicator
(0 means a successful measurement with no errors).
-
Blocks_tested
returns the number of blocks tested.
-
Block_ratio
returns the ratio of block errors to total blocks tested.
-
Block_err_cnt
returns the number of block errors.