Parity Check Matrix Generation for 5G LDPC

Hello! I know that nrLDPCEncode() in the 5G Toolbox will encode the input data according to the parity-check matrix associated with the corresponding lifting size applied to the selected base graph from the 3Gpp 5G standard. Is there function or way to obtain just the parity check matrix corresponding to the encoding process? Looking to generate the parity check matrices for 5G at varying lifting sizes.

Answer 1

[Arthi Sathyamurthi]

The nrLDPCEncode gets the input data matrix and the base graph number as its arguments. You were right about the association of parity-check matrix with the corresponding lifting size applied to the selected base graph from the 3Gpp 5G standard. If you look at the Base graph standards of NR there are two base graphs specified in the 3GPP Release 15. The base graphs decide the size of transport block. The nrLDPCEncode function calculates the lifting sizes and validates them against supported lifting sizes (by the standards). In case you want to generate the parity matrix for other lifting sizes it would be unsupported (it won’t align with the standards). You can comment off the lines in the function’s definition and give your own base graph specifications for different lifting sizes.