Design of Protograph-Based LDPC Codes with Limited Decoding Complexity

Abstract

In this letter, we present a design method to find good protograph-based low-density parity-check codes with the numbers of nonzero elements in the parity-check matrix and decoding iterations both strictly limited. We utilize the protograph-based extrinsic information transfer (PEXIT) analysis to evaluate the error performance and employ the differential evolution algorithm to devise a well-performed coding scheme. In particular, the number of iterations in the PEXIT analysis is set to a small value due to the limited iterations in the decoding process. Both numerical analyses and simulations verify that the resulting codes exhibit better performance than conventional code designs under the limitation of decoding complexity.