© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:1501.02428 · IEEE Transactions on Communications

Dynamic Weighted Bit-Flipping Decoding Algorithms for LDPC Codes

Tofar C.-Y. Chang, Yu T. Su

Published Aug 18, 2015• 31 citations

Abstract

Bit-flipping (BF) decoding of low-density parity-check codes is of low complexity but gives inferior performance in general. To improve performance and provide new BF decoder options for complexity-performance tradeoffs, we propose new designs for the flipping function (FF), the flipped bit selection (FBS) rule and the checksum weight updating schedule. The new FF adjusts the checksum weights in every iteration while our FBS rules take more information into account. These two modifications represent efforts to track more closely the evolutions of both check and variable nodes' reliabilities. Two selective update schedules are proposed to offer more performance and complexity tradeoffs. The combinations of the new FBS rule and known FFs result in new BF decoders with improved performance and a modest complexity increase. On the other hand, combining the new FF and FBS rule gives a new decoder with performance comparable to that of the normalized min-sum algorithm while if we use a much simpler FBS rule instead, the decoder suffers little performance loss with reduced complexity. We also present a simple decision-theoretical argument to justify the new checksum weight formula and a time-expanded factor graph model to explain the proposed selective weight-updating schedules.

DOI: 10.1109/tcomm.2015.2469780

Related papers

Weighted candidate bit based bit-flipping decoding algorithms for LDPC codes

Zhu Qing, Lenan Wu

In order to improve the bit-flipping (BF) decoding algorithms, a weighted hard-decision based BF decoding algorithm for low-density parity-check (LDPC) codes is presented, in which the weights of variable-nodes are employed. A new metric is defined for the weight of candidate bits not only in unsatisfied parity check equations but also in satisfied ones. The connection between min-sum decoding algorithm and the proposed algorithm is presented. Simulation results show that the new decoding algorithm can provide better FER performance and faster convergence speed than the original candidate bit based bit-flipping (CBBF) algorithm.

International Conference on Consumer Electronics, Communications and Networks (CECNet)•Nov 1, 2013•4 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

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

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

Weighted-Bit-Flipping-Based Sequential Scheduling Decoding Algorithms for LDPC Codes

Zhu Qing, Lenan Wu

Low-density parity-check (LDPC) codes can be applied in a lot of different scenarios such as video broadcasting and satellite communications. LDPC codes are commonly decoded by an iterative algorithm called belief propagation (BP) over the corresponding Tanner graph. The original BP updates all the variable-nodes simultaneously, followed by all the check-nodes simultaneously as well. We propose a sequential scheduling algorithm based on weighted bit-flipping (WBF) algorithm for the sake of improving the convergence speed. Notoriously, WBF is a low-complexity and simple algorithm. We combine it with BP to obtain advantages of these two algorithms. Flipping function used in WBF is borrowed to determine the priority of scheduling. Simulation results show that it can provide a good tradeoff between FER performance and computation complexity for short-length LDPC codes.

Mathematical Problems in Engineering•Jan 1, 2013•6 citations

A Modification to Weighted Bit-Flipping Decoding Algorithm for LDPC Codes Based on Reliability Adjustment

D. Qian, M. Jiang, Chihang Zhao +1 more

In this paper, a modification to the weighted bit- flipping (WBF) decoding algorithm for low-density parity-check (LDPC) codes is proposed. This modification, based on the adjustment in reliabilities of the check sums during iterative decoding, can be applied to various WBF algorithms. Our studies show that the modification can be achieved with a small increase in complexity, but leads to an appealing improvement in error performance.

International Conference on Communications•Jan 1, 2008•4 citations

Bit-flipping (BF) decoding of low-density parity-check codes is of low complexity but gives inferior performance in general. To improve performance and provide new BF decoder options for complexity-performance tradeoffs, we propose new designs for the flipping function (FF), the flipped bit selection (FBS) rule and the checksum weight updating schedule. The new FF adjusts the checksum weights in every iteration while our FBS rules take more information into account. These two modifications represent efforts to track more closely the evolutions of both check and variable nodes' reliabilities. Two selective update schedules are proposed to offer more performance and complexity tradeoffs. The combinations of the new FBS rule and known FFs result in new BF decoders with improved performance and a modest complexity increase. On the other hand, combining the new FF and FBS rule gives a new decoder with performance comparable to that of the normalized min-sum algorithm while if we use a much simpler FBS rule instead, the decoder suffers little performance loss with reduced complexity. We also present a simple decision-theoretical argument to justify the new checksum weight formula and a time-expanded factor graph model to explain the proposed selective weight-updating schedules.

In order to improve the bit-flipping (BF) decoding algorithms, a weighted hard-decision based BF decoding algorithm for low-density parity-check (LDPC) codes is presented, in which the weights of variable-nodes are employed. A new metric is defined for the weight of candidate bits not only in unsatisfied parity check equations but also in satisfied ones. The connection between min-sum decoding algorithm and the proposed algorithm is presented. Simulation results show that the new decoding algorithm can provide better FER performance and faster convergence speed than the original candidate bit based bit-flipping (CBBF) algorithm.

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.

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.

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.

Low-density parity-check (LDPC) codes can be applied in a lot of different scenarios such as video broadcasting and satellite communications. LDPC codes are commonly decoded by an iterative algorithm called belief propagation (BP) over the corresponding Tanner graph. The original BP updates all the variable-nodes simultaneously, followed by all the check-nodes simultaneously as well. We propose a sequential scheduling algorithm based on weighted bit-flipping (WBF) algorithm for the sake of improving the convergence speed. Notoriously, WBF is a low-complexity and simple algorithm. We combine it with BP to obtain advantages of these two algorithms. Flipping function used in WBF is borrowed to determine the priority of scheduling. Simulation results show that it can provide a good tradeoff between FER performance and computation complexity for short-length LDPC codes.