Communications Toolbox™

fec.rsenc - Construct Reed-Solomon encoder object

Synopsis

enc = fec.rsenc

enc = fec.rsenc(N,K)

enc = fec.rsenc(property1, ...)

enc = fec.rsenc(rsdec_object)

Description

enc = fec.rsenc constructs a Reed-Solomon encoder with default properties equivalent to: enc = rsenc(7,3)

enc = fec.rsenc(N,K) constructs an (N,K) Reed-Solomon encoder object enc.

enc = fec.rsenc(property1, value1, ...) constructs a Reed-Solomon encoder object enc with properties as specified by PROPERTY/VALUE pairs.

enc = fec.rsenc(rsdec_object) constructs a Reed-Solomon encoder object enc by reading the property values from the RS decoder object rsdec_object.

Properties

A Reed-Solomon encoder object has the following properties, all of which are writable, except for the ones explicitly noted otherwise.

Property	Description
`Type`	The type of encoder object. This property also displays the effective message length and codeword length, taking shortening and puncturing into consideration. This property is not writable.
`N`	The codeword length of the base code, not including shortening or puncturing.
`K`	The uncoded message length, not including shortening.
`T`	The number of errors the base code is capable of correcting. This property is not writable.
`ShortenedLength`	The number of symbols by which the code has been shortened.
`ParityPosition`	Must be 'beginning' or 'end'. Specifies if parity symbols should appear at the beginning or end of the codeword.
`GenPoly`	The generator polynomial for the code. GenPoly must be a Galois row vector that lists the coefficients, in order of descending powers, of the generator polynomial.

Methods

The fec.rsenc object has a method for encoding messages.

`codeword =encode(enc, msg)`

Encodes MSG using the Reed-Solomon code specified by a Reed-Solomon encoder object ENC. MSG must be an array of integer elements, with an integer multiple of K-ShortenedLength elements per column. There may be multiple codewords per channel, where each group of K-ShortenedLength input elements represents one message word to be encoded. Each column of MSG is considered to be a separate channel, with the same Reed-Solomon code applied to each channel.

Usage Examples

% Create Reed-Solomon encoder object.
enc = fec.rsenc(7,3);
 
% Create a message to be encoded.
msg = [0 1 0]'; 
 
% Encode msg with the ENCODE function.
code = encode(enc,msg);
 
% Create a shortened encoder
encShort = copy(enc);
encShort.ShortenedLength = 1;
 
% Create a shortened message
msgShort = [0 1]';
 
codeShort = encode(encShort,msgShort);

fec.rsdec

fft