Hi, I am trying to make a parity check matrix from non-systematic to systematic. Hence I am attaching my code below. Somewhat it is correct, but there are some problems. It would be really great if someone could help me in this. Thanks
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Information theory and coding. I am working on LDPC coding and decoding. Please check the code below
2 Comments
Answers (1)
freebil
on 10 Jun 2016
You have to do gauss jordan elimination to convert a parity check matrix to upper triangular form. For example,
H=[1 1 0 1 1 0 0 1 0 0;
0 1 1 0 1 1 1 0 0 0;
0 0 0 1 0 0 0 1 1 1;
1 1 0 0 0 1 1 0 1 0;
0 0 1 0 0 1 0 1 0 1];
There is rref() in matlab and you have to do it in GF(2). So,
HH = mod(rref(H),2)
gives
HH = 1 0 0 0 0 0 1 1 1 0
0 1 0 0 0 1 0 1 0 0
0 0 1 0 0 1 0 1 0 1
0 0 0 1 0 0 0 1 1 1
0 0 0 0 1 1 1 0 0 1
2 Comments
Aitor López Hernández
on 25 May 2017
Hello there,
Wouldn't the systematic form of a parity check matrix be of the form H = [A In-k]?
SP22
on 20 Nov 2017
This might help you to get parity check matrix in form H=[A In-k].
temp=HH(:,1:5) %Access the identity matrix through column
temp2=HH(:,6:10) %Acces the parity through column
Hsyst=horzcat(temp2,temp) %Actual systematic matrix in the form H((n-k)*n)=[P' :I(n-k)]
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