# What is a channel in coding?

## What is a channel in coding?

In computing, a channel is a model for interprocess communication and synchronization via message passing. A message may be sent over a channel, and another process or thread is able to receive messages sent over a channel it has a reference to, as a stream.

### What is channel coding theory?

Summary: The task of a channel coding is to encode the information sent over a communication channel in such a way that in the presence of some channel noise, errors can be detected and/or corrected. There are two basic coding methods. BEC (Backward Error Correction) Coding allows the receiver only errors detection.

#### What is channel coding and source coding?

1. Source coding: The source encoder converts information waveforms to bits, while the decoder converts bits back to waveforms. Channel coding: The channel encoder converts bits to signal waveform, while the decoder converts received waveform back to bits.

Where is channel coding used?

Channel coding is often used in digital communication systems to protect the digital information from noise and interference and reduce the number of bit errors. Channel coding is mostly accomplished by selectively introducing redundant bits into the transmitted information stream.

What is the main goal of channel coding?

The primary purpose of channel coding is to protect the data from being corrupted in the transmission channel. Encoding takes place in the encoder, while the decoder (Fig. 8.2) performs the reverse operation. By coding, a stream of bits is transformed into a different stream of bits, which has some desired properties.

## What do you need to know about channel coding?

A channel is an abstract model describing how the received (or retrieved) data is associated with the transmitted (or stored) data. Channel coding starts with Claude Shannon’s mathematical theory of communication. Channel coding can be either error detection coding or error correction coding.

### How to calculate mutual information in channel coding?

1. CHANNEL CODING Introduction The mutual information I (A,B), with input A and output B, measures the amount of information that the channel is able to convey over the source. If the channel is noiseless, then this is equal to the information content of source A, I (A,B)=H (A).

#### What is the error probability of channel coding?

The noise present in a channel creates unwanted errors between the input and the output sequences of a digital communication system. The error probability should be very low, nearly ≤ 10-6 for a reliable communication. The channel coding in a communication system, introduces redundancy with a control, so as to improve the reliability of the system.

How does channel coding reduce redundancy in a system?

The source coding reduces redundancy to improve the efficiency of the system. Channel coding consists of two parts of action. Mapping incoming data sequence into a channel input sequence. Inverse Mapping the channel output sequence into an output data sequence.

23/11/2020