Construction of short block length irregular low-density parity-check codes

We present a construction algorithm for short block length irregular low-density parity-check (LDPC) codes. Based on a novel interpretation of stopping sets in terms of the parity-check matrix, we present an approximate trellis-based search algorithm that detects many stopping sets. Growing the parity check matrix by a combination of random generation and the trellis-based search, we obtain codes that possess error floors orders of magnitude below randomly constructed codes and significantly better than other comparable constructions.