Bit Error Rate Test Equipment
Bit Error Rate Testers – Bit Error Rate Testing
In digital transmission, the number of bit errors is the number of received bits of a data stream over a communication channel that have been altered due to noise, interference,distortion or bit synchronization errors. The bit error rate or bit error ratio (BER) is the number of bit errors divided by the total number of transferred bits during a studied time interval. BER is a unitless performance measure, often expressed as a percentage. The bit error probability pe is the expectation value of the BER. The BER can be considered as an approximate estimate of the bit error probability. This estimate is accurate for a long time interval and a high number of bit errors.
BERT or bit error rate test is a testing method for digital communication circuits that uses predetermined stress patterns consisting of a sequence of logical ones and zeros generated by a test pattern generator. A BERT typically consists of a test pattern generator and a receiver that can be set to the same pattern. They can be used in pairs, with one at either end of a transmission link, or singularly at one end with a loopback at the remote end. BERTs are typically stand-alone specialised instruments, but can be Personal Computer based. In use, the number of errors, if any, are counted and presented as a ratio such as 1 in 1,000,000, or 1 in 1e06.
A bit error rate tester (BERT), also known as a bit error ratio tester or bit error rate test solution (BERTs) is electronic test equipment used to test the quality of signal transmission of single components or complete systems.
The main building blocks of a BERT are:
- Pattern Generator, which transmits a defined test pattern to the DUT or test system
- Error detector connected to the DUT or test system, to count the errors generated by the DUT or test system
- Clock signal generator to synchronize the pattern generator and the error detector
- Digital communication analyser is optional to display the transmitted or received signal
- Electrical-optical converter and optical-electrical converter for testing optical communication signals.