New paper in IEEE/OSA Journal of Lightwave Technology

The following paper has been accepted for publication in IEEE/OSA Journal of Lightwave Technology:

F. Steiner, E. Ben Yacoub, B. Matuz, G. Liva, and A. Graell i Amat, "One and Two Bit Message Passing for SC-LDPC Codes with Higher-Order Modulation," IEEE/OSA Journal of Lightwave Technology, to appear. [arXiv][IEEExplore]

Abstract: Low complexity decoding algorithms are necessary to meet data rate requirements in excess of 1 Tbps. In this paper, we study one and two bit message passing algorithms for belief propagation decoding of low-density parity-check (LDPC) codes and analyze them by density evolution. The variable nodes (VNs) exploit soft information from the channel output. To decrease the data flow, the messages exchanged between check nodes (CNs) and VNs are represented by one or two bits. The newly proposed quaternary message passing (QMP) algorithm is com- pared asymptotically and in finite length simulations to binary message passing (BMP) and ternary message passing (TMP) for spectrally efficient communication with higher-order modulation and probabilistic amplitude shaping (PAS). To showcase the potential for high throughput forward error correction, spatially coupled LDPC codes and a target spectral efficiency (SE) of 3bits/QAM symbol are considered. Gains of about 0.7dB and 0.1dB are observed compared to BMP and TMP, respectively. The gap to unquantized belief propagation (BP) decoding is reduced to about 0.75dB. For smaller code rates, the gain of QMP compared to TMP is more pronounced and amounts to 0.24dB in the considered example.