Construction of short-length LDPC codes with low error floor

It has been known that stopping sets and trapping sets are the main contributors to error floors exhibited by short-length low-density parity-check (LDPC) codes. In this work, a new metric called ldquoapproximate cycle set extrinsic message degree (ACSE)rdquo is defined to help removing stopping sets with small size and bad trapping sets. Based on the new metric, we propose a code-construction algorithm that produces LDPC codes with very low error floors. Finally, we compare the error rates between codes produced by the proposed algorithm and MacKay code.