DVB-S2 LDPC Decoding Using Robust Check Node Update Approximations

• Published in: IEEE transactions on broadcasting Vol. 54; no. 1; pp. 120 - 126
• Main Authors: Papaharalabos, S., Papaleo, M., Mathiopoulos, P.T., Neri, M., Vanelli-Coralli, A., Corazza, G.E.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.03.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Algorithms; Applied sciences; Approximation; Approximation methods; Broadcasting; Broadcasting. Videocommunications. Audiovisual; Code standards; Coding; Coding, codes; Computation; Computational complexity; Decoding; Degradation; Digital video broadcasting; Error correction codes; Exact sciences and technology; Information, signal and communications theory; iterative decoding; Low-Density Parity-Check (LDPC) codes; Modulation; Modulation, demodulation; Noise levels; Parity check codes; Robustness; Satellite broadcasting; Signal and communications theory; Studies; Telecommunications; Telecommunications and information theory; Television; Performance evaluation; Approximate method; Optimal algorithm; Updating; Computational complexity; Iterative decoding; Degradation; Computation time; Wide band; Modulation; Broadcasting; Parity check codes; Error correcting code; Low-Density Parity-Check (LDPC) codes; Modulation coding; Parity check; Digital video broadcasting
• ISSN: 0018-9316; 1557-9611
• DOI: 10.1109/TBC.2007.911365

Broadband satellite services to fixed terminals are currently offered in the forward link by the 2nd generation (2G) digital video broadcasting satellite (DVB-S2) standard. For this standard the use of powerful low-density parity-check (LDPC) error correcting codes has been adopted performing within approximately 1 dB from the Shannon capacity limit. This paper studies and compares for the first time in a systematic manner different approximation methods used in check node update computation of DVB-S2 LDPC decoding with the aim of reducing computational complexity. Various performance evaluation results are presented for a wide range of DVB-S2 parameters, such as LDPC codeword size, coding rate, modulation format and including several decoding algorithms. It is shown that the proposed check node update approximations have a robust behavior, i.e. the resulting performance is quite independent of the DVB-S2 modulation and coding parameters. It is further shown that these approximations perform very close to the optimal sum-product algorithm (SPA) in degradation, which is less than 0.2 dB. Despite this small degradation, the reduction in computational complexity compared to the optimal SPA is significant and can be as high as 40% in computational time savings.