A Novel Construction Scheme with Linear Encoding Complexity for LDPC Codes

Abstract

Low-density parity-check (LDPC) codes can achieve better performance and lower decoding complexity than turbo codes and other error control codes. But it is difficult for LDPC codes to be commercial because of their high encoding complexity and consequent encoding delay. Using an efficient encoding method proposed by Richardson and Urbanke, we can efficiently reduce the LDPC encoding complexity apparently to the linear complexity, but the encoding delay becomes much longer because of the forward substitution operation which can only be performed serially. In this paper, we consider the LDPC encoding method combined with the construction of H matrix to construct the LDPC codes with linear encoding complexity, which we named as LEC-LDPC (linear encoding complexity LDPC) codes. The encoding complexity of the LEC-LDPC codes is exactly linear due to the inverse operation been omitted, and we can remove the forward substitution operation to greatly decrease the encoding latency.