On the Waterfall Performance of Finite-Length SC-LDPC Codes Constructed From Protographs Articles uri icon

publication date

  • February 2016

start page

  • 345

end page

  • 361


  • 2


  • 34

International Standard Serial Number (ISSN)

  • 0733-8716

Electronic International Standard Serial Number (EISSN)

  • 1558-0008


  • An analysis of spatially coupled low-density parity-check (SC-LDPC) codes constructed from protographs is proposed. Given the protograph used to generate the SC-LDPC code ensemble, a set of scaling parameters to characterize the average finite-length performance in the waterfall region is computed. The error performance of structured SC-LDPC code ensembles is shown to follow a scaling law similar to that of unstructured randomly constructed SC-LDPC codes. Under a finite-length perspective, some of the most relevant SC-LDPC protograph structures proposed to date are compared. The analysis reveals significant differences in their finite-length scaling behavior, which is corroborated by simulation. Spatially coupled repeat-accumulate codes present excellent finite-length performance, as they outperform in the waterfall region SC-LDPC codes of the same rate and better asymptotic thresholds.


  • low-density parity-check (ldpc) codes; spatially coupled ldpc codes constructed from protographs; iterative decoding; finite-length analysis; capacity-achieving codes; spatially-coupled ldpc; parity-check codes; convolutional-codes; threshold saturation; correcting codes; minimum distance; ensembles; capacity; graphs; block