Programming a Bit Error Measurement

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 .

1. Set the cell power to a low operating level.
2. Configure BER measurement parameters using the SETup subsystem.
3. Set the measurement type (either residual Type IA, Type IB, Type II, or non-residual Type IA, Type IB, Type II).
4. Set the cell power to a low level for BER measurement.
5. Use the READ:BERROR? command to initiate and fetch the BER measurement results.
6. Set the cell power to a normal operating level.

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

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.

Related Topics

Bit Error Measurement

SETup:GBERror

INITiate

FETCh:GBERror

Bit Error Troubleshooting

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.

Related Topics

EGPRS SRB Bit Error Measurement

SETup:SBERror

INITiate

FETCh:SBERror

EGPRS SRB Bit Error Troubleshooting