We propose a novel variant of the gradient descent bit-flipping (GDBF) algorithm for decoding low-density parity-check (LDPC) codes over the binary symmetric channel. The new bit-flipping rule is based on the reliability information passed from neighboring nodes in the corresponding Tanner graph. The name SuspicionDistillation reflects the main feature of the algorithm—that in every iteration, we assign a level of suspicion to each variable node about its current bit value. The level of suspicion of a variable node is used to decide whether the corresponding bit will be flipped. In addition, in each iteration, we determine the number of satisfied and unsatisfied checks that connect a suspicious node with other suspicious variable nodes. In this way, in the course of iteration, we “distill” such suspicious bits and flip them. The deterministic nature of the proposed algorithm results in a low-complexity implementation, as the bit-flipping rule can be obtained by modifying the original GDBF rule by using basic logic gates, and the modification is not applied in all decoding iterations. Furthermore, we present a more general framework based on deterministic re-initialization of the decoder input. The performance of the resulting algorithm is analyzed for the codes with various code lengths, and significant performance improvements are observed compared to the state-of-the-art hard-decision-decoding algorithms.
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LDPC decoders with re-initializations based on synergy of hard decision and message passing principles
In this paper we propose the approaches that combine two types
of iterative decoding algorithms that are usually used for decoding
of low density parity check codes (LDPC). One strategy is based
on a low-complexity bit-flipping algorithm, and the proposed
modification enable significant performance improvement, with no
significant increase of the average computing complexity. The
other strategy is based on belief propagation decoder, and the
resulting decoder has improved error correction capabilities for the
codes with short codeword length.
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- NSF-PAR ID:
- 10342843
- Date Published:
- Journal Name:
- Conference on Electronics, Telecommunication, Computing, Automation and Nuclear Engineering
- Page Range / eLocation ID:
- 758 - 763
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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