In digital telecommunications, channel coding is a pre-transmission mapping applied to a digital signal or data file, usually designed to make error-correction possible. A digital system is one that uses discrete values rather than a continuous spectrum of values: compare analog. ... Telecommunication is the extension of communication over a distance. ... Digital Signal represents more than one meaning. ... In computer science and information theory, error correction consists of using methods to detect and/or correct errors in the transmission or storage of data by the use of some amount of redundant data and (in the case of transmission) the selective retransmission of incorrect segments of the data. ...

Error correction is implemented by using more digits (bits in case of a binary channel) than the number strictly necessary for the samples, and having the receiver compute the most likely valid message that could have resulted in the received one. In mathematics and computer science, a numerical digit is a symbol, e. ... A bit (abbreviated b) is the most basic information unit used in computing and information theory. ...

Channel coding should not be confused with source coding, which is the elimination of redundancy in order to make efficient use of storage space and/or transmission channels. In computer science, data compression or source coding is the process of encoding information using fewer bits, or information units, thanks to specific encoding schemes. ...

Channel coding should also not be confused by line coding, which is the coding performed in order to adapt the transmitted signal to the (electrical) characteristics of a transmission channel. In telecommunication, a line code is a code chosen for use within a communications system for transmission purposes. ...

In a common communication system, at the transmitting point there is first source coding, then channel coding, then line coding.

Types of channel coding include:

• parity checks
• Hamming code
• Reed-Muller code
• Reed-Solomon code
• Turbo coding

Examples of source coding are: In telecommunication, a Hamming code is an error-correcting code named after its inventor, Richard Hamming. ... The Reed-Muller codes are a family of linear error-correcting codes used in communications. ... Reed-Solomon error correction is a coding scheme which works by first constructing a polynomial from the data symbols to be transmitted and then sending an over-sampled plot of the polynomial instead of the original symbols themselves. ... Turbo codes are a class of recently-developed high-performance error correction codes finding use in deep-space satellite communications and other applications where designers seek to achieve maximal information transfer over a limited-bandwidth communication link in the presence of data-corrupting noise. ...

• Huffman coding
• morse code
• Binary coding

Examples of line coding include: B8ZS, HDB3, 2B1Q, AMI and Gray coding. In computer science, Huffman coding is an entropy encoding algorithm used for lossless data compression. ... Morse code is a system of representing letters, numbers and punctuation marks by means of a code signal sent intermittently. ... Binary coding is the term used to describe how information, normally numbers, are stored in binary, radix-2 form. ... B8ZS is an abbreviation for bipolar with eight-zero substitution. ... HDB3 (High-density bipolar-3 zeros) is a telecommunications line code mainly used in Japan and Europe (for example, in E-1 lines) and is based on AMI. It is also very similar to the B8ZS encoding used in T-1 lines. ... (Redirected from 2B1Q) The physical layer is level one in the seven level OSI model of computer networking. ... In computing and telecommunications, abbreviation for Alternate Mark Inversion, a method of encoding data to be transmitted. ... A Gray code is a binary numeral system where two successive values differ in only one digit, originally designed to prevent spurious output from electromechanical switches. ...