Programming a Bit Error Measurement
Last updated: December 3, 2008
This section contains three programming examples:
Programming a Bit Error Measurement for GSM
This section provides an example of how to make the bit error (BER) measurement via GPIB.
The following procedure assumes that an active link is established between the test set and the mobile station. See
Establishing an Active GSM Link with the Mobile Station
.
-
Set the cell power to a low operating level.
-
Configure BER measurement parameters using the SETup subsystem.
-
Set the measurement type (either residual Type IA, Type IB, Type II, or non-residual Type IA, Type IB, Type II).
-
Set the cell power to a low level for BER measurement.
-
Use the READ:BERROR? command to initiate and fetch the BER measurement results.
-
Set the cell power to a normal operating level.
Programming Example
10 OUTPUT 714;"SETUP:BERROR:TIMEOUT:TIME 5"! BER measurement times out after
20 ! 5 seconds.
30 OUTPUT 714;"CALL:CELL:POWER:AMPLITUDE -102 DBM"! Sets the cell power level
40 ! to a "low" level for the
50 ! BER measurement.
60 OUTPUT 714;"SETUP:BERROR:CONTINUOUS OFF" ! Configures a BER measurement to
70 ! Single Trigger.
80 OUTPUT 714;"SETUP:BERROR:COUNT 10000" ! Sets the number of bits to measure
90 ! at 10,000.
100 OUTPUT 714;"SETUP:BERROR:CLSDELAY:STIME 500 MS" ! Sets the Close Loop Delay
110 ! to 500 ms.
120 OUTPUT 714;"SETUP:BERROR:SLCONTROL ON" ! Sets the Signal Loop Control state to on.
130 OUTPUT 714;"SETUP:BERROR:TYPE TYPEIA" ! Sets the Measurement Type to IA.
140 OUTPUT 714;"SETUP:BERROR:LDCONTROL:AUTO OFF" ! Configure loopback delay
150 ! control to manual.
160 OUTPUT 714;"SETUP:BERROR:MANUAL:DELAY 1" ! Set frame delay to 6 frames in order
170 ! to correlate uplink and downlink bits.
180 OUTPUT 714;"READ:BERROR?" ! Initiate and fetch BER measurement results.
201 ENTER 714;Integrity,Bits_tested,Bit_err_ratio,Bit_err_count
202 PRINT "Integrity";TAB(20);Integrity
203 PRINT "Bits Tested";TAB(20);Bits_tested
204 PRINT "Bit Error Ratio";TAB(20);Bit_err_ratio
205 PRINT "Bit Error Count";TAB(20);Bit_err_count
206 OUTPUT 714;"FETCH:BERROR:COUNT:CRC?" ! Query CRC Count results.
220 ENTER 714;Crc_count
221 PRINT "CRC Count";TAB(20);Crc_count
230 OUTPUT 714;"CALL:CELL:POWER:AMPLITUDE -85 DBM" ! Returns the cell power level
240 ! to a good level.
250 END
Returned values
The measurements returned by this program are:
-
Integrity
returns the
Integrity Indicator
(0 means a successful measurement with no errors).
-
Bits_tested
returns the number of bits tested.
-
Bit_err_ratio
returns the ratio of bit errors to total bits tested.
-
Bit_err_count
returns the number of bit errors.
-
Crc_count
returns the CRC count (cyclic redundancy check).
Programming a Bit Error Measurement for GPRS
This section provides an example of how to make the GPRS bit error (BER) 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 (using
CALL:FUNCtion:CONNection: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 BER 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 Bit Error measurement parameters using the SETup subsystem.
-
Configure the downlink PDTCH parameters using the CALL subsystem.
-
Start the Bit Error measurement using the INITiate subsystem.
-
Use the FETCh? command to obtain Bit 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 -60 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:GBER:TIM:TIME 5" ! BER measurement times out after
90 ! 5 seconds.
100 OUTPUT 714;"SET:GBER:CONT OFF" ! Configures a BER measurement to
110 ! Single Trigger.
120 OUTPUT 714;"SET:GBER:COUN 10000" ! Sets the number of bits to measure
130 ! at 10,000.
140 OUTPUT 714;"SET:GBER: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:GBER" ! Start a BER measurement.
240 OUTPUT 714;"FETC:GBER?"
250 ENTER 714;Integrity,Bits_tested,Bit_ratio,Bit_err_cnt
260 END
Returned values
The measurements returned by this program are:
-
Integrity
returns the
Integrity Indicator
(0 means a successful measurement with no errors).
-
Bits_tested
returns the number of bits tested.
-
Bit_ratio
returns the ratio of bit errors to total bits tested.
-
Bit_err_cnt
returns the number of bit errors.
Programming an EGPRS SRB Bit Error Measurement
This section provides an example of how to make the EGPRS SRB bit error (SBER) 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 SRB Loopback (using
CALL:FUNCtion:CONNection: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 SBER measurements when the test set's operating mode is set to EGPRS BCH+PDTCH test mode (see
CALL:OPERating:MODE
).
-
Configure the BCH and PDTCH parameters using the CALL subsystem.
-
Configure the EGPRS SRB Bit Error measurement parameters using the SETup subsystem.
-
Configure the downlink PDTCH parameters using the CALL subsystem.
-
Start the EGPRS SRB Bit Error measurement using the INITiate subsystem.
-
Use the FETCh? command to obtain EGPRS SRB Bit 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 -60 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:MCSC MCS3,MCS3" ! Set the modulation coding scheme to MCS3.
70 ! Configure the measurement parameters
80 OUTPUT 714;"SET:SBER:TIM:TIME 5" ! BER measurement times out after
90 ! 5 seconds.
100 OUTPUT 714;"SET:SBER:CONT OFF" ! Configures a BER measurement to
110 ! Single Trigger.
120 OUTPUT 714;"SET:SBER:COUN 80000" ! Sets the number of bits to measure
130 ! at 80,000.
140 OUTPUT 714;"SET:SBER: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:SBER" ! Start a BER measurement.
240 OUTPUT 714;"FETC:SBER?"
250 ENTER 714;Integrity,Bits_tested,Bit_ratio,Bit_err_cnt
260 END
Returned values
The measurements returned by this program are:
-
Integrity
returns the
Integrity Indicator
(0 means a successful measurement with no errors).
-
Bits_tested
returns the number of bits tested.
-
Bit_ratio
returns the ratio of bit errors to total bits tested.
-
Bit_err_cnt
returns the number of bit errors.
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