Input data symbols are written to a synchronization (sync) adder, which appends a pseudo randomly (PN) generated sync bit to generate a sync word. Sync words are sent to a receiver where synchronization is recovered. The receiver re-generates the same PN sequence that was generated at the transmitter....http://www.google.de/patents/US5392289?utm_source=gb-gplus-sharePatent US5392289 - Error rate measusrement using a comparison of received and reconstructed PN sequences
