Line coding is the process of converting digital data to digital signals. By this technique, a sequence of bits is converted to a digital signal. At the sender side, digital data are encoded into a digital signal. While at the receiver side, the digital data are recreated by decoding the digital signal.
For successful line coding, there should be self-synchronizing i.e., both receiver and sender clock should be synchronized. Also, there should be immunity to noise and interference.
At the very least, the line-code encoder serves as an interface between the TTL level signals of the transmitter and those of the analog channel. Likewise, the line-code decoder serves as an interface between the analog signals of the channel and the TTL level signals required by the digital receiver.
