R&S SMJ100A, Operating Manual

Page: 196 / 874

Instrument Function
R&S
®
SMJ100A
180 Operating Manual 1403.7458.32 ─ 14
5.4 Bit and Block Error Rate Measurements - BERT Block
The R&S SMJ contains an integrated bit error rate tester which makes it possible to
evaluate a signal demodulated and decoded by a DUT by measuring the bit error rate.
A known PRBS-modulated data sequence (PRBS =
p seudo r andom b inary s equence)
is sent to the DUT. The PRBS data sequence is decoded by the DUT and sent to the
R&S
SMJ in the form of clock and data signals. The bit error rate tester of the
R&S SMJ synchronizes to the known PRBS sequence and counts the bit errors. The
quotient obtained by dividing the number of error bits by the total number of bits is the
BER.
In addition, a block error rate measurement can be used to verify CRC checksums.
The ratio of errored blocks to total blocks yields the block error rate.
The settings are shown in the block diagram in the "BERT" function block and in the
menu of the same name that is accessed via the MENU button.
The equipment layout for the basic unit (R&S SMJ with B10x frequency option)
includes the option R&S SMJ-K80 (Bit Error Rate Tester).
Bit and Block Error Rate Measurements - BERT Block