R&S AFQ100A
Bit Error Rate Measurements - BERT Block
1401.3084.32 4.69
E-3
Data Enable
The data signals usually contain not only PRBS data but also other data (e.g. sync and preambles) that
would result in bit errors. The BER measurement for this data can then be interrupted using the
Data
Enable
signal. The
Data Enable
signal is fed in at the BERT input.
access
user data
guard
header
clock
data
enable
frame
data
Fig. 4-6
TDMA signal with user data that contains the PRBS data sequence and various check fields which should be
ignored for the bit error rate measurement. Below that the associated clock and
Data Enable
signals are indicated.
Pattern Ignore
Bit sequences of 32 bits or more with only "1" or "0", which some mobile radio standards provide
instead of frame data when faulty frames are detected, can also be excluded from the measurement
using the
Pattern Ignore
function (see figure).
50 Bits
PRBS at Generator
PRBS at DUT Output
BER "active"
Drop Out of DUT
These bits are ingored
Fig. 4-7
Example of functionality of
Pattern Ignore
: 50 bits were set to "0" by the DUT. These 50 bits plus the preceding
"0" are ignored in the bit error rate measurement.
