344 Keysight M8000 Series of BER Test Solutions User Guide
6 Setting up Analyzer
Pattern Synchronization
The M8020A/M8030A/M8040A calculates bit error rates by comparing the
received data with the expected data patterns. To do this, it needs to know
where the start of the pattern is located in the data stream.
Introduction to Pattern Synchronization
Pattern synchronization (sync) refers to aligning the incoming data pattern
with the internal reference pattern.
Hardware-Generated Patterns
For 2^n-1 PRBS patterns, bits from the incoming data pattern "seed" the
Analyzer's Generator, causing it to generate a precisely aligned internal
reference pattern.
Memory-Based Patterns
For software-generated and user patterns, a 48-bit pattern from the
pattern is used as a detect word. Optimally, this detect word should be
unique within the entire pattern. The Analyzer searches for this detect
word within the incoming data stream, and uses the point in the data
stream as a reference, and compares all following bits with the pattern. If
the measured BER is better than the synchronization BER, the Analyzer
will be synchronized.
There are thus three possible outcomes for a synchronization:
• Single instance of the detect word in the data stream
To Next Page
Loading...
Need help?
General
