CRC

dataword=[1 0 0 1];
divisor=[1 0 1 1];
l=length(dataword);
remainder=dataword;
ag=3; %as we augmented 3 zeros at the end of dataword
for i=1:4
    if(remainder(1)==1)
        remainder=bitxor(remainder,divisor);
    else
        remainder=bitxor(remainder,[0 0 0 0]);
    end
    if(ag>0)
        remainder=[remainder(2:4) 0];
    else
        remainder=[remainder(2:4)];
    end
    ag=ag-1;
end

codeword=[dataword remainder]