rsdecodecalcsynd.m

RS编码程序设计

%
%   File Name   :   RsDecodeCalcSynd.m
%   Abstract    :   伴随式计算子模块
%   
%   Version     :   1.0    2008-5-30
%*************************************************************************

function [Syndrome] = RsDecodeCalcSynd(RsCodeWithNoise)


t = 2;
% GF(2.^4)域上运算表
alpha(1,:) = [1;2;4;8;3;6;12;11;5;10;7;14;15;13;9];

% 计算本原元幂次的平方 
for ii = 1:15
    alpha(2,ii) =  RsSymbolMul(alpha(1,ii), alpha(1,ii));
end;
% 计算本原元幂次的3次方 
for ii = 1:15
    alpha(3,ii) =  RsSymbolMul(alpha(2,ii), alpha(1,ii));
end;
% 计算本原元幂次的4次方
for ii = 1:15
    alpha(4,ii) =  RsSymbolMul(alpha(3,ii), alpha(1,ii));
end;

% 计算r(alpha.^j)求伴随式，j=1,2,...,2t
for jj = 1:2*t
    temp = 0;
    temp_product = 0;
           
    for ii = 1:15
         
        temp_product = RsSymbolMul(RsCodeWithNoise(ii), alpha(jj,ii));
        temp = RsSymbolAdd(temp, temp_product);
    end;

    Syndrome(jj) = temp;
end;