Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

IEEE Communications Letters

Multi-Stage Bit-Flipping Decoding Algorithms for LDPC Codes

Tofar C.-Y. Chang, Pin-Han Wang, Yu T. Su

Published Jun 20, 2019• 16 citations
Publisher

Abstract

We present two general multi-stage (MS) bit-flipping (BF) decoding algorithms for low-density parity-check (LDPC) codes. Both algorithms consist of soft-decision (SD) and hard-decision BF decoding parts. In comparison with known MS LDPC decoders, our approach is much simpler as all stages share the same BF structure. The only complexity increase is due to the use of an adaptive stage-switching (SS) mechanism which gives near-optimal SS timing. A new design issue we address is that the first-stage algorithm's parameter has to be re-tuned to achieve the optimal overall performance. The numerical results demonstrate that the proposed decoding methods can significantly improve the error-rate performance of the conventional SD BF decoders.

DOI
10.1109/lcomm.2019.2924210

Related papers

An efficient bit-flipping decoding algorithm for LDPC codes

Tso-Cho Chen

In this paper, a new method for improving hard-decision bit-flipping (BF) decoding is proposed for low-density parity-check codes. The flipping criterion is derived theoretically from the soft-decision belief-propagation decoding algorithm. The proposed BF decoding algorithm is channel independent and is improved by introducing a more efficient method for computing the reliability of the parity checks. Extensive simulations are provided to demonstrate the efficiency of the proposed algorithm. Simulation results show that the proposed algorithm can achieve about 1.5dB coding gain improvement at BER = 5×10−6while reducing up to 48% iterations for decoding and maintaining low decoding complexity, compared with the conventional weighted BF algorithm.

Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC)•Jul 1, 2012•6 citations

Improved Bit-Flipping Method for Decoding Structured Low-Density Parity-Check Codes

Meiling Zhang

An improved bit-flipping(BF) algorithm with low complexity for decoding structured low-density parity-check codes(LDPC) is proposed to improve the performance of the hard-decision BF algorithm.The hard-decision bits are divided into two groups based on the magnitudes of the received symbols,and at each iteration,the proposed algorithm can flip more than one bit with using two thresholds,and the flipping error probability is effectively decreased.The improved BF algorithm requires some real number comparisons before iterations and requires only logical operations during the iterations.Compared with the weighted bit-flipping algorithm and its modifications,the new method is with significantly lower complexity.Simulations show that the proposed algorithm is provided with very fast convergence speed and excellent performance with significantly low complexity.

Beijing Youdian Xueyuan xuebao•Jan 1, 2012•0 citations

Two-Round Selection-Based Bit Flipping Decoding Algorithm for LDPC Codes

Soufian Addi, Mostafa Belkasmi, Ahlam Berkani +1 more

This paper presents a novel iterative reliability-based bit flipping (BF) algorithm for decoding low-density parity-check codes. The new decoder is a single BF algorithm called two-round selection -based bit flipping. It introduces the idea of a two-round selection of the flipped bit, based successively on hard and soft received channel values. In the first stage, a set of unreliable bits is identified, and then a second selection is used, to pick out among them the bit to flip. In the second round of selection, the initial belief about received signals, contributes efficiently to selecting the best candidate bit. We demonstrate through simulations over the binary-input additive white Gaussian noise channel and the Rayleigh fading channel that the proposed algorithm exhibits better decoding performance when compared with some well-known soft decision BF algorithms. A complexity analysis of the proposal and a comparison to other BF decoders are also presented.

Wireless Communications and Mobile Computing•Nov 28, 2023•0 citations

Adaptive Threshold Technique for Bit-Flipping Decoding of Low-Density Parity-Check Codes

Junho Cho, Wonyong Sung

The bit-flipping (BF) algorithm for decoding of low-density parity-check (LDPC) codes requires less complex hardware than other decoding algorithms, but its error correcting performance needs to be improved. In this letter, a threshold adaptation scheme is applied to BF algorithm based decoding of LDPC codes. Our experiments show that the optimal threshold value for BF depends on the error conditions, and threshold adjustment during decoding helps to prevent meaningless no-flipping iterations. Based on these statistical observations, the adaptive threshold technique is proposed to pursue both the maximum error correcting capability and the fastest decoding convergence.

IEEE Communications Letters•Aug 5, 2010•32 citations

An Improved Iterative Bit-flipping Decoding Algorithm for Low-density Parity-check Codes

Meiling Zhang

An improved iterative bit-flipping(BF) algorithm adapted for decoding low-density parity-check(LDPC) codes is proposed to improve the performance of the hard-decision BF decoding algorithm.The new algorithm uses an alternating threshold pattern to determine the bits whether to be flipped or not,and the flipping error probability is effectively decreased.Simulation results show that compared with BF algorithm,the improved BF algorithm improves both the error-correction performance and the convergence speed while maintaining the low computational complexity.

Telecommunication Engineering•Jan 1, 2012•0 citations

Enhanced Bit-Flipping Decoding Using Refined Checksum Weights and Flip Metrics for LDPC Codes

Tofar C.-Y. Chang, Po-Ming Chou, Kai-Chieh Lin +1 more

Bit-flipping (BF) algorithms for decoding low-density parity-check (LDPC) codes have attracted considerable attention due to their low complexity and high parallelism. While recent improvements have enabled certain BF decoders to approach the performance of belief-propagation (BP) decoding, many of these enhancements rely on complex mechanisms such as loop detection, decoder switching, or costly online computations. In this paper, we propose enhanced BF decoding algorithms that integrate refined checksum weighting and flipping function designs. The proposed weighting scheme jointly exploits soft-valued channel information and hard-decision consistency to better reflect the reliability of each checksum, while maintaining negligible online complexity. Additionally, we propose a flipping function design that implicitly discourages repeated flipping by incorporating the accumulated flip count into its computation, thus suppressing decoding loops without requiring explicit loop detection or decoder switching. Simulation results demonstrate that the proposed decoding strategies yield notable performance gains over existing BF decoders, with only a minor complexity increase.

IEEE VTS Asia Pacific Wireless Communications Symposium (APWCS)•Aug 20, 2025•1 citation
We present two general multi-stage (MS) bit-flipping (BF) decoding algorithms for low-density parity-check (LDPC) codes. Both algorithms consist of soft-decision (SD) and hard-decision BF decoding parts. In comparison with known MS LDPC decoders, our approach is much simpler as all stages share the same BF structure. The only complexity increase is due to the use of an adaptive stage-switching (SS) mechanism which gives near-optimal SS timing. A new design issue we address is that the first-stage algorithm's parameter has to be re-tuned to achieve the optimal overall performance. The numerical results demonstrate that the proposed decoding methods can significantly improve the error-rate performance of the conventional SD BF decoders.
In this paper, a new method for improving hard-decision bit-flipping (BF) decoding is proposed for low-density parity-check codes. The flipping criterion is derived theoretically from the soft-decision belief-propagation decoding algorithm. The proposed BF decoding algorithm is channel independent and is improved by introducing a more efficient method for computing the reliability of the parity checks. Extensive simulations are provided to demonstrate the efficiency of the proposed algorithm. Simulation results show that the proposed algorithm can achieve about 1.5dB coding gain improvement at BER = 5×10−6while reducing up to 48% iterations for decoding and maintaining low decoding complexity, compared with the conventional weighted BF algorithm.
An improved bit-flipping(BF) algorithm with low complexity for decoding structured low-density parity-check codes(LDPC) is proposed to improve the performance of the hard-decision BF algorithm.The hard-decision bits are divided into two groups based on the magnitudes of the received symbols,and at each iteration,the proposed algorithm can flip more than one bit with using two thresholds,and the flipping error probability is effectively decreased.The improved BF algorithm requires some real number comparisons before iterations and requires only logical operations during the iterations.Compared with the weighted bit-flipping algorithm and its modifications,the new method is with significantly lower complexity.Simulations show that the proposed algorithm is provided with very fast convergence speed and excellent performance with significantly low complexity.
This paper presents a novel iterative reliability-based bit flipping (BF) algorithm for decoding low-density parity-check codes. The new decoder is a single BF algorithm called two-round selection -based bit flipping. It introduces the idea of a two-round selection of the flipped bit, based successively on hard and soft received channel values. In the first stage, a set of unreliable bits is identified, and then a second selection is used, to pick out among them the bit to flip. In the second round of selection, the initial belief about received signals, contributes efficiently to selecting the best candidate bit. We demonstrate through simulations over the binary-input additive white Gaussian noise channel and the Rayleigh fading channel that the proposed algorithm exhibits better decoding performance when compared with some well-known soft decision BF algorithms. A complexity analysis of the proposal and a comparison to other BF decoders are also presented.
The bit-flipping (BF) algorithm for decoding of low-density parity-check (LDPC) codes requires less complex hardware than other decoding algorithms, but its error correcting performance needs to be improved. In this letter, a threshold adaptation scheme is applied to BF algorithm based decoding of LDPC codes. Our experiments show that the optimal threshold value for BF depends on the error conditions, and threshold adjustment during decoding helps to prevent meaningless no-flipping iterations. Based on these statistical observations, the adaptive threshold technique is proposed to pursue both the maximum error correcting capability and the fastest decoding convergence.
An improved iterative bit-flipping(BF) algorithm adapted for decoding low-density parity-check(LDPC) codes is proposed to improve the performance of the hard-decision BF decoding algorithm.The new algorithm uses an alternating threshold pattern to determine the bits whether to be flipped or not,and the flipping error probability is effectively decreased.Simulation results show that compared with BF algorithm,the improved BF algorithm improves both the error-correction performance and the convergence speed while maintaining the low computational complexity.
Bit-flipping (BF) algorithms for decoding low-density parity-check (LDPC) codes have attracted considerable attention due to their low complexity and high parallelism. While recent improvements have enabled certain BF decoders to approach the performance of belief-propagation (BP) decoding, many of these enhancements rely on complex mechanisms such as loop detection, decoder switching, or costly online computations. In this paper, we propose enhanced BF decoding algorithms that integrate refined checksum weighting and flipping function designs. The proposed weighting scheme jointly exploits soft-valued channel information and hard-decision consistency to better reflect the reliability of each checksum, while maintaining negligible online complexity. Additionally, we propose a flipping function design that implicitly discourages repeated flipping by incorporating the accumulated flip count into its computation, thus suppressing decoding loops without requiring explicit loop detection or decoder switching. Simulation results demonstrate that the proposed decoding strategies yield notable performance gains over existing BF decoders, with only a minor complexity increase.