Line code

Line code is a digital baseband modulation technique used in telecommunications for data transmission. It represents the digital signal to be transported over a communication channel. Different line coding schemes are employed to achieve various desirable characteristics such as minimizing DC bias, providing sufficient timing information for clock recovery at the receiver, facilitating error detection, and reducing bandwidth requirements.

The choice of a specific line code depends on the characteristics of the transmission channel, the desired data rate, and the complexity of the encoding and decoding circuitry. Some common line coding techniques include Non-Return-to-Zero (NRZ), Return-to-Zero (RZ), Manchester encoding, and Bipolar Alternate Mark Inversion (AMI).

Key considerations in selecting a line code include its power spectral density (PSD), which affects bandwidth usage and electromagnetic interference, and its ability to support reliable clock recovery, crucial for synchronizing the receiver with the incoming data stream. Effective line coding is essential for ensuring efficient and reliable digital communication.