On short cycle enumeration in biregular bipartite graphs.

A number of recent works have used a variety of combinatorial constructions to derive Tanner graphs for LDPC codes and some of these LDPC codes have been shown to perform well in terms of their probability of errors and error floors. Such graphs are bipartite and many of these constructions yield biregular graphs, where the degree of left vertices is a constant c + 1 and that of the right vertices...