LDPC H matrix with diffrent rate

Hello,

I need a LDPC (Gallager) H matrix with different rate 2/3 1/4 8/9 and so on. I found H matrices with rate of 1/2 as .mat file. I'm looking for another rate now. please let me know if you have it.

Answer 1

[Vidya Viswanathan]

I understand that you are looking for a method to generate parity check matrix of LDPC code for different code rates.

Refer to the following documentation page on " dvbs2ldpc " function that returns parity-check matrix of LDPC code with different code rates from DVB-S.2 standard:

http://www.mathworks.com/help/comm/ref/dvbs2ldpc.html

Note that this function is available in Communications System Toolbox.

[Hamid Reza Barzegar]

Thanks for your reply, but in this function you mentioned it doesn't make a binary matrices it's make a positions of 1 in spars matrices.

actually now I'm looking for this question.

I want to convert David MacKay decimal matrices in to binary format this is the MacKay Encyclopedia of Sparse Graph Codes:

http://www.inference.phy.cam.ac.uk/mackay/codes/data.html#l142

which I need it in binary format.

Additional link: http://www.inference.phy.cam.ac.uk/mackay/codes/alist.html

Answer 2

[Albashir Youssef]

I created a new code read the alist format by defining the loctions of of ones in each row of the parity check matrix

and the matlab code example to read H matrix with size N = 96 and M = 64 :

clc

clear all

close all

N = 96; % No. of rows

M = 64; % No. of Columns

% Creating Zero Matrix with the required size

H = zeros(M,N);

% Positions of ones for each coulmn from Mackay Alist Format

pos_of_ones_col = [1 33 11;

2 34 1;

3 35 4;

4 36 30;

5 37 28;

6 38 31;

7 39 32;

8 40 26;

9 41 2;

10 42 13;

11 43 18;

12 44 27;

13 45 19;

14 46 7;

15 47 29;

16 48 10;

17 49 6;

18 50 23;

19 51 25;

20 52 3;

21 53 9;

22 54 20;

23 55 8;

24 56 15;

25 57 22;

26 58 14;

27 59 5;

28 60 16;

29 61 17;

30 62 12;

31 63 24;

32 64 21;

48 44 54;

38 8 44;

1 28 39;

8 47 37;

22 3 43;

28 23 30;

13 52 5;

53 33 63;

16 51 23;

21 38 26;

32 49 10;

26 63 36;

55 15 2;

56 36 49;

62 14 52;

27 16 57;

31 46 4;

3 56 16;

59 45 60;

63 40 25;

43 42 41;

33 24 58;

2 30 35;

50 39 21;

7 4 8;

17 59 34;

14 20 47;

6 26 19;

39 19 24;

47 62 42;

61 1 32;

46 13 11;

45 53 28;

41 17 22;

40 12 14;

5 10 17;

19 21 20;

64 2 56;

36 7 3;

4 55 61;

10 29 31;

15 37 53;

54 35 59;

18 34 6;

9 57 50;

49 9 48;

12 18 51;

44 43 64;

11 64 62;

20 61 40;

34 32 29;

37 41 33;

29 27 7;

58 48 13;

24 5 9;

51 22 38;

57 54 45;

30 50 1;

42 25 55;

23 11 15;

25 31 18;

52 6 27;

35 60 46;

60 58 12];

for i = 1:N

for j = 1:3

H((pos_of_ones_col(i,j)),i) = 1;

end

end

% good luck

Answer 3

[Noah Levy]

I recently wrote some code to read Mackay's alist files directly to a MATLAB H matrix:

https://gist.github.com/nmsl1993/4d18de8812c6f2802a9f

Answer 4

[Hamid Reza Barzegar]

Thanks Noah for the code. your code is working well with this matrix 12 16 4 3 4 4 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 8 10 13 4 7 9 13 2 5 7 10 4 6 11 14 3 9 15 16 1 6 9 10 4 8 12 15 2 6 12 16 1 7 14 16 3 5 12 14 2 11 13 15 1 5 8 11 6 9 12 3 8 11 1 5 10 2 4 7 3 10 12 4 6 8 2 3 9 1 7 12 2 5 6 1 3 6 4 11 12 7 8 10 1 2 11 4 9 10 5 7 11 5 8 9 but when i try with other matrices is not working. you can find it as an attachment. could you please check it