H = dvbs2ldpc(r) returns
the parity-check matrix H of the LDPC code with code rate
r from the Digital Video Broadcasting standard DVB-S.2. The block
length of the code is 64,800.
H = dvbs2ldpc(r,outputFormat)
specifies the format for the output parity-check matrix.
Code rate, specified as 1/4, 1/3,
2/5, 1/2, 3/5,
2/3, 3/4, 4/5,
5/6, 8/9, or 9/10.
Data Types: double
outputFormat — Output format 'sparse' | 'indices'
Output format for parity-check matrix H, specified as
'sparse' or 'indices'.
If you set this value to 'sparse', H is a
sparse logical matrix. If you set this value to 'indices',
H is a two-column matrix that defines the row and column indices
of the 1s in H.
The default parity-check matrix of size 32,400-by-64,800 corresponds to an irregular
LDPC code with the structure shown in this table.
Row
Number of 1s per Row
1
6
2 to 32400
7
Column
Number of 1s per Column
1 to 12960
8
12961–32400
3
Columns from 32,401 to 64,800 form a lower triangular matrix. Only the
elements on the main diagonal of the matrix and the subdiagonal immediately below the
main diagonal are 1s. This LDPC code is used in conjunction with a BCH code in the
DVB-S.2 standard to achieve a packet error rate below at about 0.7 dB to 1 dB from the Shannon limit.
Extended Capabilities
C/C++ Code Generation Generate C and C++ code using MATLAB® Coder™.
Usage notes and limitations:
All inputs must be constants. Expressions or variables are allowed if their values do
not change.