TDM code transmission method - involves addition of logic ONE to each code group with coding upset at first bit of frame

摘要

The method is used for the transmission of pseudo-ternary digital signals. A pulse frame is produced with several equal size groups of n signal bits. A logic "1" bit is added before each group. The TDM signal so enlarged is subjected to an AMI coding, but the AMI rule is upset at the first bit of the pulse frame. An AMI decoding is carried out and the bit timing signal is recovered at the receiving end. A frame synchronisation signal is derived from the upsetting of the AMI rule, and the added bits are eliminated.