Differential biphase binary code decoder - measures time intervals between pulses over preset period to increase maximum data transmission rate

摘要

Decoding system for signal trains in a differential biphase binary code where it is normally necessary to know the frequency and phase of the clock source signals synchronising the incoming message. The system overcomes the response time problems associated with using a local clock and synchronisation words in the message and to increase the data transmission rate. The decoder uses measurement of time intervals between selected pulses over some preset period, and delivers a local clock pulse in response to each such pulse. A further circuit detects the presence or otherwise of a transition pulse between them, both circuits being based on local clock source synchronised comparators.