gusucode.com > wlan工具箱matlab源码程序 > wlan/wlan/+wlan/+internal/ldpcMatrix.m
function [H, G] = ldpcMatrix(rate, blockLength)
%LDPCMATRIX Parity-check matrix and generator matrix of WLAN LDPC code
%
% [H, G] = ldpcMatrix(rate, blockLength) returns the parity-check
% matrix and the generator matrix of the WLAN LDPC code with the
% specified coding rate and block length.
%
% rate must be equal to '1/2', '2/3', '3/4', or '5/6'.
% blockLength must be equal to 648, 1296, or 1944.
%
% See also ldpcEncodeCore, ldpcDecodeCore.
% Copyright 2015-2016 The MathWorks, Inc.
%#codegen
% blockLength should 648, 1296, or 1944
blockSize = blockLength/24; % Possible values for blockSize: 27, 54, 81
switch blockLength
case 648
switch rate
case '1/2'
% Prototype for rate 1/2 and block length 648
P = [
0 -1 -1 -1 0 0 -1 -1 0 -1 -1 0 1 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
22 0 -1 -1 17 -1 0 0 12 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1 -1 -1
6 -1 0 -1 10 -1 -1 -1 24 -1 0 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1 -1
2 -1 -1 0 20 -1 -1 -1 25 0 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1
23 -1 -1 -1 3 -1 -1 -1 0 -1 9 11 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1
24 -1 23 1 17 -1 3 -1 10 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1
25 -1 -1 -1 8 -1 -1 -1 7 18 -1 -1 0 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1
13 24 -1 -1 0 -1 8 -1 6 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1
7 20 -1 16 22 10 -1 -1 23 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1
11 -1 -1 -1 19 -1 -1 -1 13 -1 3 17 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1
25 -1 8 -1 23 18 -1 14 9 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0
3 -1 -1 -1 16 -1 -1 2 25 5 -1 -1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0
];
case '2/3'
% Prototype for rate 2/3 and block length 648
P = [
25 26 14 -1 20 -1 2 -1 4 -1 -1 8 -1 16 -1 18 1 0 -1 -1 -1 -1 -1 -1
10 9 15 11 -1 0 -1 1 -1 -1 18 -1 8 -1 10 -1 -1 0 0 -1 -1 -1 -1 -1
16 2 20 26 21 -1 6 -1 1 26 -1 7 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1
10 13 5 0 -1 3 -1 7 -1 -1 26 -1 -1 13 -1 16 -1 -1 -1 0 0 -1 -1 -1
23 14 24 -1 12 -1 19 -1 17 -1 -1 -1 20 -1 21 -1 0 -1 -1 -1 0 0 -1 -1
6 22 9 20 -1 25 -1 17 -1 8 -1 14 -1 18 -1 -1 -1 -1 -1 -1 -1 0 0 -1
14 23 21 11 20 -1 24 -1 18 -1 19 -1 -1 -1 -1 22 -1 -1 -1 -1 -1 -1 0 0
17 11 11 20 -1 21 -1 26 -1 3 -1 -1 18 -1 26 -1 1 -1 -1 -1 -1 -1 -1 0
];
case '3/4'
% Prototype for rate 3/4 and block length 648
P = [
16 17 22 24 9 3 14 -1 4 2 7 -1 26 -1 2 -1 21 -1 1 0 -1 -1 -1 -1
25 12 12 3 3 26 6 21 -1 15 22 -1 15 -1 4 -1 -1 16 -1 0 0 -1 -1 -1
25 18 26 16 22 23 9 -1 0 -1 4 -1 4 -1 8 23 11 -1 -1 -1 0 0 -1 -1
9 7 0 1 17 -1 -1 7 3 -1 3 23 -1 16 -1 -1 21 -1 0 -1 -1 0 0 -1
24 5 26 7 1 -1 -1 15 24 15 -1 8 -1 13 -1 13 -1 11 -1 -1 -1 -1 0 0
2 2 19 14 24 1 15 19 -1 21 -1 2 -1 24 -1 3 -1 2 1 -1 -1 -1 -1 0
];
otherwise % case '5/6'
% Prototype for rate 5/6 and block length 648
P = [
17 13 8 21 9 3 18 12 10 0 4 15 19 2 5 10 26 19 13 13 1 0 -1 -1
3 12 11 14 11 25 5 18 0 9 2 26 26 10 24 7 14 20 4 2 -1 0 0 -1
22 16 4 3 10 21 12 5 21 14 19 5 -1 8 5 18 11 5 5 15 0 -1 0 0
7 7 14 14 4 16 16 24 24 10 1 7 15 6 10 26 8 18 21 14 1 -1 -1 0
];
end
case 1296
switch rate
case '1/2'
% Prototype for rate 1/2 and block length 1296
P = [
40 -1 -1 -1 22 -1 49 23 43 -1 -1 -1 1 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
50 1 -1 -1 48 35 -1 -1 13 -1 30 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1 -1 -1
39 50 -1 -1 4 -1 2 -1 -1 -1 -1 49 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1 -1
33 -1 -1 38 37 -1 -1 4 1 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1
45 -1 -1 -1 0 22 -1 -1 20 42 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1
51 -1 -1 48 35 -1 -1 -1 44 -1 18 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1
47 11 -1 -1 -1 17 -1 -1 51 -1 -1 -1 0 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1
5 -1 25 -1 6 -1 45 -1 13 40 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1
33 -1 -1 34 24 -1 -1 -1 23 -1 -1 46 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1
1 -1 27 -1 1 -1 -1 -1 38 -1 44 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1
-1 18 -1 -1 23 -1 -1 8 0 35 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0
49 -1 17 -1 30 -1 -1 -1 34 -1 -1 19 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0
];
case '2/3'
% Prototype for rate 2/3 and block length 1296
P = [
39 31 22 43 -1 40 4 -1 11 -1 -1 50 -1 -1 -1 6 1 0 -1 -1 -1 -1 -1 -1
25 52 41 2 6 -1 14 -1 34 -1 -1 -1 24 -1 37 -1 -1 0 0 -1 -1 -1 -1 -1
43 31 29 0 21 -1 28 -1 -1 2 -1 -1 7 -1 17 -1 -1 -1 0 0 -1 -1 -1 -1
20 33 48 -1 4 13 -1 26 -1 -1 22 -1 -1 46 42 -1 -1 -1 -1 0 0 -1 -1 -1
45 7 18 51 12 25 -1 -1 -1 50 -1 -1 5 -1 -1 -1 0 -1 -1 -1 0 0 -1 -1
35 40 32 16 5 -1 -1 18 -1 -1 43 51 -1 32 -1 -1 -1 -1 -1 -1 -1 0 0 -1
9 24 13 22 28 -1 -1 37 -1 -1 25 -1 -1 52 -1 13 -1 -1 -1 -1 -1 -1 0 0
32 22 4 21 16 -1 -1 -1 27 28 -1 38 -1 -1 -1 8 1 -1 -1 -1 -1 -1 -1 0
];
case '3/4'
% Prototype for rate 3/4 and block length 1296
P = [
39 40 51 41 3 29 8 36 -1 14 -1 6 -1 33 -1 11 -1 4 1 0 -1 -1 -1 -1
48 21 47 9 48 35 51 -1 38 -1 28 -1 34 -1 50 -1 50 -1 -1 0 0 -1 -1 -1
30 39 28 42 50 39 5 17 -1 6 -1 18 -1 20 -1 15 -1 40 -1 -1 0 0 -1 -1
29 0 1 43 36 30 47 -1 49 -1 47 -1 3 -1 35 -1 34 -1 0 -1 -1 0 0 -1
1 32 11 23 10 44 12 7 -1 48 -1 4 -1 9 -1 17 -1 16 -1 -1 -1 -1 0 0
13 7 15 47 23 16 47 -1 43 -1 29 -1 52 -1 2 -1 53 -1 1 -1 -1 -1 -1 0
];
otherwise % case '5/6'
% Prototype for rate 5/6 and block length 1296
P = [
48 29 37 52 2 16 6 14 53 31 34 5 18 42 53 31 45 -1 46 52 1 0 -1 -1
17 4 30 7 43 11 24 6 14 21 6 39 17 40 47 7 15 41 19 -1 -1 0 0 -1
7 2 51 31 46 23 16 11 53 40 10 7 46 53 33 35 -1 25 35 38 0 -1 0 0
19 48 41 1 10 7 36 47 5 29 52 52 31 10 26 6 3 2 -1 51 1 -1 -1 0
];
end
otherwise % case 1944
switch rate
case '1/2'
% Prototype for rate 1/2 and block length 1944
P = [
57 -1 -1 -1 50 -1 11 -1 50 -1 79 -1 1 0 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
3 -1 28 -1 0 -1 -1 -1 55 7 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1 -1 -1
30 -1 -1 -1 24 37 -1 -1 56 14 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1 -1
62 53 -1 -1 53 -1 -1 3 35 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1 -1
40 -1 -1 20 66 -1 -1 22 28 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1 -1
0 -1 -1 -1 8 -1 42 -1 50 -1 -1 8 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1
69 79 79 -1 -1 -1 56 -1 52 -1 -1 -1 0 -1 -1 -1 -1 -1 0 0 -1 -1 -1 -1
65 -1 -1 -1 38 57 -1 -1 72 -1 27 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1 -1
64 -1 -1 -1 14 52 -1 -1 30 -1 -1 32 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1 -1
-1 45 -1 70 0 -1 -1 -1 77 9 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0 -1
2 56 -1 57 35 -1 -1 -1 -1 -1 12 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 0
24 -1 61 -1 60 -1 -1 27 51 -1 -1 16 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0
];
case '2/3'
% Prototype for rate 2/3 and block length 1944
P = [
61 75 4 63 56 -1 -1 -1 -1 -1 -1 8 -1 2 17 25 1 0 -1 -1 -1 -1 -1 -1
56 74 77 20 -1 -1 -1 64 24 4 67 -1 7 -1 -1 -1 -1 0 0 -1 -1 -1 -1 -1
28 21 68 10 7 14 65 -1 -1 -1 23 -1 -1 -1 75 -1 -1 -1 0 0 -1 -1 -1 -1
48 38 43 78 76 -1 -1 -1 -1 5 36 -1 15 72 -1 -1 -1 -1 -1 0 0 -1 -1 -1
40 2 53 25 -1 52 62 -1 20 -1 -1 44 -1 -1 -1 -1 0 -1 -1 -1 0 0 -1 -1
69 23 64 10 22 -1 21 -1 -1 -1 -1 -1 68 23 29 -1 -1 -1 -1 -1 -1 0 0 -1
12 0 68 20 55 61 -1 40 -1 -1 -1 52 -1 -1 -1 44 -1 -1 -1 -1 -1 -1 0 0
58 8 34 64 78 -1 -1 11 78 24 -1 -1 -1 -1 -1 58 1 -1 -1 -1 -1 -1 -1 0
];
case '3/4'
% Prototype for rate 3/4 and block length 1944
P = [
48 29 28 39 9 61 -1 -1 -1 63 45 80 -1 -1 -1 37 32 22 1 0 -1 -1 -1 -1
4 49 42 48 11 30 -1 -1 -1 49 17 41 37 15 -1 54 -1 -1 -1 0 0 -1 -1 -1
35 76 78 51 37 35 21 -1 17 64 -1 -1 -1 59 7 -1 -1 32 -1 -1 0 0 -1 -1
9 65 44 9 54 56 73 34 42 -1 -1 -1 35 -1 -1 -1 46 39 0 -1 -1 0 0 -1
3 62 7 80 68 26 -1 80 55 -1 36 -1 26 -1 9 -1 72 -1 -1 -1 -1 -1 0 0
26 75 33 21 69 59 3 38 -1 -1 -1 35 -1 62 36 26 -1 -1 1 -1 -1 -1 -1 0
];
otherwise % case '5/6'
% Prototype for rate 5/6 and block length 1944
P = [
13 48 80 66 4 74 7 30 76 52 37 60 -1 49 73 31 74 73 23 -1 1 0 -1 -1
69 63 74 56 64 77 57 65 6 16 51 -1 64 -1 68 9 48 62 54 27 -1 0 0 -1
51 15 0 80 24 25 42 54 44 71 71 9 67 35 -1 58 -1 29 -1 53 0 -1 0 0
16 29 36 41 44 56 59 37 50 24 -1 65 4 65 52 -1 4 -1 73 52 1 -1 -1 0
];
end
end
% Expand each number in P into a sub-matrix (blockSize by blockSize)
[numRows, numCols] = size(P);
H = zeros([numRows numCols]*blockSize);
for i = 1:numRows
for j = 1:numCols
H(((i-1)*blockSize+1):i*blockSize, ((j-1)*blockSize+1):j*blockSize) = ...
BuildSubBlock(blockSize, P(i,j));
end
end
if nargout > 1
% Calculate the generator matrix
G = par2gen(H);
end
function M = BuildSubBlock(s, shift)
if shift == -1
M = zeros(s);
else
M = eye(s);
if shift > 0
shift = shift - 1;
M(:) = M(:,[end-shift:end 1:(end-shift-1)]);
end
end
function G = par2gen(H)
[parityCheckLen,blockLength] = size(H);
infolen = blockLength - parityCheckLen;
H1 = H(:,1:infolen);
H2 = H(:,(infolen+1):end);
% Do LU factorization on H2
[PL, PB, rowOrder, invertible] = gf2factorize(H2);
if invertible % Should always be invertible for LDPC codes supported in 802.11
PB = PB(rowOrder, :);
end
pbits = false(parityCheckLen,infolen);
for i = 1:parityCheckLen
PL(i,i) = 0;
PB(i,i) = 0;
end
for i = 1:infolen
r = gf2solve(PL,H1(:,i),1); % Matrix multiply
pbits(:,i) = gf2solve(PB,r(rowOrder),-1); % Backward substitution
end
G = [eye(infolen) double(pbits')];
function [A, B, chosen_pivots, invertible] = gf2factorize(X)
% Factorize a square matrix in GF(2).
n = size(X,1);
A = logical(eye(n,n));
B = full(X~=0);
chosen_pivots = zeros(n,1); % Haven't chosen any pivots yet.
invertible = true; % Assume that X is invertible in GF(2).
for col = 1:n
candidate_rows = B(:,col);
candidate_rows(chosen_pivots(1:(col-1))) = 0; % Never use a chosen pivot.
candidate_rows_ind = find(candidate_rows); % Convert into row indices.
if isempty(candidate_rows_ind)
invertible = false; % X is not invertible in GF(2).
break;
else
pivot = candidate_rows_ind(1); % Choose the first candidate row as the pivot row.
chosen_pivots(col) = pivot; % Record this pivot.
% Find all nonzero elements in the pivot row.
% They will be xor-ed with the corresponding elements in other
% candidate rows.
columnind = find(B(pivot,:));
% Subtract the pivot row from all other candidate_rows.
% Take advantage of the fact that we are working in GF(2).
% Just use logical NOT.
% As we continue in this loop, B will become "psychologically"
% upper triangular.
for k = 1:length(columnind)
for j = 2:length(candidate_rows_ind)
B(candidate_rows_ind(j), columnind(k)) = not(B(candidate_rows_ind(j), columnind(k)));
end
end
% Update the lower triangular matrix A.
for j = 2:length(candidate_rows_ind)
A(candidate_rows_ind(j), pivot) = 1;
end
end
end
function y = gf2solve(A, y, direction)
if direction == 1
columnindex = 1; % Start from the first column for forward substitution
else
columnindex = length(y); % Start from the last column for backward substitution
end
columncounter = 1;
while columncounter < length(y)
if y(columnindex)
y(:) = xor(y,A(:,columnindex));
end
columncounter = columncounter + 1;
columnindex = columnindex + direction;
end
% Following code is used to generate the mat files for the encoder. The G
% matrix is reshaped into group of 16 bits, which is converted into decimal
% and stored as unsigned integer in ldpcMatrices.mat file.
% rate = '1/2';
% blockLength = 648;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_1_2_648 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '1/2';
% blockLength = 1296;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_1_2_1296 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '1/2';
% blockLength = 1944;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_1_2_1944 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '2/3';
% blockLength = 648;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_2_3_648 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '2/3';
% blockLength = 1296;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_2_3_1296 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '2/3';
% blockLength = 1944;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_2_3_1944 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '3/4';
% blockLength = 648;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_3_4_648 = uint16(bi2de(reshape(outg,[],12)));
%
% rate = '3/4';
% blockLength = 1296;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_3_4_1296 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '3/4';
% blockLength = 1944;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_3_4_1944 = uint16(bi2de(reshape(outg,[],12)));
%
% rate = '5/6';
% blockLength = 648;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_5_6_648 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '5/6';
% blockLength = 1296;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_5_6_1296 = uint16(bi2de(reshape(outg,[],16)));
%
% rate = '5/6';
% blockLength = 1944;
% [~,g] = wlan.internal.ldpcMatrix(rate,blockLength);
% sizeG = size(g);
% outg = g(:,sizeG(1)+1:end).';
% ldpcMatrices.PT_5_6_1944 = uint16(bi2de(reshape(outg,[],16)));
%
% save('ldpcMatrices.mat','-struct', 'ldpcMatrices')