Ohio University graduate student chapter of the American Mathematical Society lecture, March 23

The Ohio University graduate student chapter of the American Mathematical Society lecture features Henry Chimal-Dzul discussing Quasi-Cyclic Low-Density Parity Check Codes of girth g>6 on March 23 from 4-5 p.m. in Morton 115. 

Chimal-Dzul is a visiting professor at the University of Notre Dame.

Abstract:  Quasi-Cyclic Low Density Parity Check (QC-LDPC) codes are one of the most promising classes of LDPC codes. Due to their quasi-cyclic structure and low-density, they have been adopted in various standard broadband networks and storage systems. One of the most interesting problems concerning this family of codes is to investigate conditions so that they have large girth, a parameter known to affect the efficiency of their decoding algorithm, namely the Bit Flipping Algorithm. The girth of a QC-LDPC code depends at the same time on another parameter known as "lifting degree", which determines the length of the code. In this talk, we investigate conditions for a QC-LDPC code to have girth at least 6. The minimum lifting degree is also investigated and fully determined in various cases.  The results are obtained through linear algebra techniques, but the constructions translate into problems in Graph theory, number theory and combinatorics.

Participants can be in-person at Morton or join us online via the Teams link is below.

 https://teams.microsoft.com/l/meetup-join/19%3ameeting_Y2EwNDZkYzgtMDFmZS00MDk3LTgzMzAtOWJiMTQ3MjI5OGY0%40thread.v2/0?context=%7b%22Tid%22%3a%22f3308007-477c-4a70-8889-34611817c55a%22%2c%22Oid%22%3a%220b70ee14-d619-4fd4-aedd-d804aa59c91d%22%7d