Hi all, I'd just like to share a status of how my LDPC implementation project is going. When the summer started, Manu and I made a list of the LDPC-related algorithms for encoding, decoding, and parity check matrix construction that we had found in our literature review. We then divided them up such that there would be no overlap in our efforts. The algorithms that I put on my list were:
1. Regular and irregular parity check matrix construction functions 2. Generating a code that is optimized for PSK 3. Constructing quasi-cyclic codes which are especially efficient for encoding 4. Performing encoding as described by Richardson & Urbanke in Appendix A of 'Modern Coding Theory' (manipulating the parity-check matrix into an approximate upper triangulation form which reduces complexity during the real-time encoding steps) 5. Bit-flip decoding, a hard decision algorithm 6. Min-sum algorithm for decoding So far, I've written prototype functions for these methods in python, using numpy: #1/regular, #4, and #5. Right now, I'm at the stage where I'm trying to link them all together and confirm that the processes perform as expected before moving on to converting them to C++. The challenge that I'm facing is that the parity check matrices being created by my function are not full rank, and so they don't work with the encoding algorithm. I have tried a method to manipulate them into being full rank before encoding but it was not successful. This is my top priority right now - to be able to have the parity-check matrices that I am creating work with the encoding algorithm that I've written up. Then I'd like to finish testing the chain of processes before moving on to creating classes that inherit from those in the FEC API. My GitHub repo is here: https://github.com/tracierenea/GNU-Radio-GSoC2013 Any questions or comments, just let me know. Thanks, Tracie Perez _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
