LDPC encoder/decoder with a rate of 1/3 and a length of the code being less than 10,000 bits?

Hello,

Is there any LDPC Matlab code that can encode a message with a rate of 1/3 and with a length of the code being less than 10,000?

I could find "dvbs2ldpc", but the block length of the code is 64,800. I would like to find some Matlab code OF LDPC that has a rate of 1/3 and the length of the code is about 1024 or anything less than 10,000, is this possible?

Answer 1

[vidyesh]

Hello R. R.

It is my understanding that you want to encode a LDPC code with a rate of 1/3 and a length of less than 10,000. Additionally, you prefer not to use the 'dvbs2ldpc' function due to its default length.

To achieve this, you can utilize the 'ldpcQuasiCyclicMatrix' function, which takes two parameters: 'blockSize' and the matrix 'P'. The matrix 'P' is a (N – K)-by-N matrix, where N > K > 0. It is essential that the last N – K rows of the parity-check matrix are invertible in a Galois field of order 2.

Here, N represents the LDPC codeword block length, and K represents the number of information bits in the LDPC codeword.

For a 1/3 rate, N = 3*K and the value of 'blockSize' will depend on the length of the message.

Refer to the following links for detailed information and an example with 3/4 rate.

• https://www.mathworks.com/help/comm/ref/ldpcencoderconfig.html
• https://www.mathworks.com/help/comm/ref/ldpcquasicyclicmatrix.html

Hope this answer helps.

[Sam]

Can you give an example of a 'P' matrix that satisfies such conditions?