Communications Blockset

Error Detection and Correction

The Error Detection and Correction library contains three sublibraries:

• Block, which contains blocks that implement the encoding and decoding of linear, cyclic, BCH, Hamming, and Reed-Solomon codes
• Convolutional, which contains blocks that implement convolutional encoding and decoding
• CRC, which contains blocks that append cyclic redundancy check (CRC) bits to data, and detect errors

The main Error Detection and Correction library appears below. You can open it by double-clicking on its icon in the main Communications Blockset library (commlib), or by typing commedac2 at the MATLAB prompt. Each icon in the Error Detection and Correction window represents a sublibrary. In Simulink, double-clicking on one of these icons opens the sublibrary. In this document, clicking on one of the icons below jumps to an overview of that sublibrary.

Block Coding

You can open the Block sublibrary by double-clicking on the Block icon in the main Error Detection and Correction library, or by typing commblkcod2 at the MATLAB prompt.

Note    In this document, you can jump to a block's reference page by clicking on its icon below.

The table below lists and describes the blocks in the Block sublibrary of the Error Detection and Correction library. For information about a specific block, see the reference pages that follow.

Block Name	Purpose
BCH Decoder	Decode a BCH code to recover binary vector data
BCH Encoder	Create a BCH code from binary vector data
Binary Cyclic Decoder	Decode a systematic cyclic code to recover binary vector data
Binary Cyclic Encoder	Create a systematic cyclic code from binary vector data
Binary-Output RS Decoder	Decode a Reed-Solomon code to recover binary vector data
Binary-Input RS Encoder	Create a Reed-Solomon code from binary vector data
Binary Linear Decoder	Decode a linear block code to recover binary vector data
Binary Linear Encoder	Create a linear block code from binary vector data
Hamming Decoder	Decode a Hamming code to recover binary vector data
Hamming Encoder	Create a Hamming code from binary vector data
Integer-Output RS Decoder	Decode a Reed-Solomon code to recover integer vector data
Integer-Input RS Encoder	Create a Reed-Solomon code from integer vector data

Convolutional Coding

You can open the Convolutional sublibrary by double-clicking on the Convolutional icon in the main Error Detection and Correction library, or by typing commcnvcod2 at the MATLAB prompt.

Note    In this document, you can jump to a block's reference page by clicking on its icon below.

The table below lists and describes the blocks in the Convolutional sublibrary of the Error Detection and Correction library. For information about a specific block, see the reference pages that follow.

Block Name	Purpose
APP Decoder	Decode a convolutional code using the a posteriori probability (APP) method
Convolutional Encoder	Create a convolutional code from binary data
Viterbi Decoder	Decode convolutionally encoded data using the Viterbi algorithm

Cyclic Redundancy Check Coding

You can open the CRC sublibrary by double-clicking on the CRC icon in the main Error Detection and Correction library, or by typing commcrc2 at the MATLAB prompt.

Note    In this document, you can jump to a block's reference page by clicking on its icon below.

The table below lists and describes the blocks in the CRC sublibrary of the Error Detection and Correction library. For information about a specific block, see the reference pages that follow.

Block Name	Purpose
CRC-N Generator	Generate CRC bits according to the selected CRC method and append them to input data
CRC-N Syndrome Detector	Detect errors in the input data according to the specified CRC method
General CRC Generator	Generate CRC bits according to the generator polynomial and append them to input data
General CRC Syndrome Detector	Detect errors in the input data according to the generator polynomial

Source Coding

Interleaving