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

International Conference on Consumer Electronics

Combined SCF and SCAN Algorithms for Soft-Output Polar Decoding

Pin-Geng Zeng, Cheng-Hung Dixson Lin, Pei-Hsuan Chen

Published Jan 6, 2024• 0 citations
Publisher

Abstract

Polar code has lower coding and decoding requirements, linear complexity, and superior channel performance, so it is proven to be close to the Shannon limit for 5G communication. Successive cancellation (SC) is a polar code decoding method, but its performance has a lot of room for optimization, and flip methodology is one of its basic optimizations. Successive Cancellation Flip (SCF) has a good error correction capability. But due to the repetition of the SC decoder during computation, it has a very long latency. Moreover, SCF output is a hard decision, so it is not capable of soft input and soft output decoder. To allow SCF to be used in more decoding environments, the Hybrid SCF/SCAN proposed in this paper can freely select soft output and hard output, and the proposed architecture can reduce the problem of repeatedly computing SC decode.

DOI
10.1109/icce59016.2024.10444390

Related papers

Hybrid BP-SC/SCF Decoding for Polar Codes

Chih-Heng Cheng, Cheng-Hung Dixson Lin

There are two main algorithms, successive cancellation (SC) algorithm and brief propagation (BP) algorithm, for decoding polar code. The SC algorithm has better error-correcting performance and the BP algorithm has low latency. The hybrid BP-SC decoding combines these two decoding algorithms and achieves improvements. Furthermore, the successive cancellation flip (SCF) algorithm improves the error-correcting performance for the SC algorithm, but it has higher computation complexity and latency. Based on the hybrid BP-SC decoding, we proposed a hybrid BP-SC/SCF decoding for polar codes in this paper to further improve the error-correcting performance. The result shows our approach outperforms to frame error rates (FER) of the SC decoding and BP decoding at least 0.5-dB and outperforms hybrid BP-SC decoding by 0.2-dB to 0.4-dB. Compared with the SCF decoding, the hybrid BPSC/SCF decoding has a small degradation of FER in a highquality channel but it significantly reduces the average computation complexity.

IEEE International Conference on Consumer Electronics - Taiwan (ICCE-Taiwan)•Sep 15, 2021•1 citation

A Low-Latency Successive Cancellation Hybrid Decoder for Convolutional Polar Codes

Yu Wang, Shikai Qiu, Lirui Chen +4 more

By adopting successive cancellation list decoding (SCL), polar codes demonstrate competitive error correction performance over LDPC and Turbo codes. However, SCL decoding suffers from high computational complexity and long decoding latency, especially when the list size is very large. Successive cancellation flip (SCF), as another decoding algorithm that can achieve high error correction performance, has a complexity that is close to that of successive cancellation (SC) decoding. With the observation that SCL and SCF decoding are similar at giving more chances to inspect possible codewords simultaneously or sequentially, a novel hybrid decoder is proposed in this paper, which essentially combines the ideas of SCF and SCL decoders. Moreover, in order to compensate for the degradation of performance caused by the reduction of path splitting and further reduce the decoding latency, the convolutional polar codes are adopted with a designed bit-flipping set. Simulation results demonstrate that the proposed decoder achieves the reduction of decoding latency while attaining better performance than conventional CRC-aided SCL decoder.

IEEE International Conference on Acoustics Speech and Signal Processing•Apr 9, 2020•1 citation

Interleaver-Aided Successive Cancellation Flip Decoding Algorithm for Polar Codes

Haseong Kim, Hyunjee Lee, Hosung Park

When the code length is finite, the successive cancellation list (SCL) decoding of polar codes shows as good error-correction performance as low-density parity-check codes and turbo codes and it will be used in high-speed communications. However, since the hardware complexity of the SCL increases linearly as the size of the list increases, it is difficult to use the high-complexity SCL decoding for devices with limited resource such as IoT devices. The successive cancellation flip (SCF) decoding algorithm has been proposed to solve the problem of high hardware complexity and to enhance the error-correction performance of successive cancellation decoding. However, the conventional SCF decoding has high computational complexity. In this paper, we propose the interleaver-aided successive cancellation flip (ISCF) decoding to reduce the computational complexity. The computational complexity of the ISCF decoding is less by at least 32% than the conventional SCF decoding for error frame at Eb/N0=3.5dB.

IEEE International Conference on Computer and Communications (ICCC)•Dec 1, 2018•1 citation

Successive-Cancellation Flip Decoding of Polar Codes with a Simplified Restart Mechanism

Ilshat Sagitov, Charles Pillet, Alexios Balatsoukas‐Stimming +1 more

Polar codes are a class of error-correcting codes that provably achieve the capacity of practical channels. The successive-cancellation flip (SCF) decoder is a low-complexity decoder that was proposed to improve the performance of the successive-cancellation (SC) decoder as an alternative to the high-complexity successive-cancellation list (SCL) decoder. The SCF decoder improves the error-correction performance of the SC decoder, but the variable execution time and the high worst-case execution time pose a challenge for the realization of receivers with fixed-time algorithms. The dynamic SCF (DSCF) variation of the SCF decoder further improves the error-correction performance but the challenge of decoding delay remains. In this work, we propose a simplified restart mechanism (SRM) that reduces the execution time of SCF and DSCF decoders through conditional restart of the additional trials from the second half of the codeword. We show that the proposed mechanism is able to improve the execution time characteristics of SCF and DSCF decoders while providing identical error-correction performance. For a DSCF decoder that can flip up to 3 simultaneous bits per decoding trial, the average execution time, the average additional execution time and the execution-time variance are reduced by approximately 31%, 37% and 57%, respectively. For this setup, the mechanism requires approximately 3.9% additional memory.

arXiv:2303.01561•IEEE Wireless Communications and Networking Conference•Mar 1, 2023•4 citations

Threshold Successive Cancellation Flip Decoding Algorithm for Polar Codes: Design and Performance

Zhicheng Liu, Liuquan Yao, Shuai Yuan +3 more

In this paper, we propose the threshold successive cancellation flip (Th-SCF) decoding algorithm for polar codes, which enhances the performance of the SC decoder while maintaining low complexity. Theoretical analysis reveals that Th-SCF asymptotically delays the first error position (FEP, the first part where the SC decoder fails) with probability 1, ensuring high decoding performance. Simulation results show that the Th-SCF algorithm achieves performance comparable to the dynamic SC flip (D-SCF) algorithm, but with a reduction in complexity by eliminating the need for sorting operations. A key contribution of this work is the rigorous theoretical framework supporting the Th-SCF algorithm, distinguishing it from existing SC flip (SCF) decoding methods. This theoretical foundation not only explains the performance improvements but also provides insights into the underlying mechanisms of flipping. The proposed Th-SCF algorithm demonstrates strong performance across a wide range of code lengths and rates, and its performance remains stable within a certain threshold range, indicating its practical applicability in real-world communication systems. These results offer valuable perspectives for the design of efficient flip decoding strategies in 5G and future networks.

Entropy•Jun 12, 2025•1 citation

Reducing Search Complexity of Dynamic SC-Flip Decoding for Polar Codes

Xinyuan Qiao, Hangxuan Cui, Jun Ting Lin +1 more

Polar codes are the first error-correcting codes that achieve the Shannon limit under successive cancellation (SC) decoding when the code length is infinite. However, the error-correcting performance of SC decoding is mediocre for short and moderate code lengths. Dynamic successive cancellation flip (DSCF) decoding has been proposed that performs extra SC decoding trails with multi-bit flipping to improve the performance of short and moderate polar codes. The DSCF decoding suffers from high computational complexity and decoding latency since all information bits are tested when searching for the flipping candidates, which leads to intensive metric calculations. To reduce the search complexity of the DSCF, a method based on the critical set (CS) is proposed in this paper to narrow the search range and two types of special nodes, rate-0 nodes and repetition nodes, are incorporated for further complexity reduction. Simulation results show that the proposed method can achieve more than 70% reduction in calculations on metrics, and up to 22.79% reduction in calculations on nodes without performance loss compared to the original DSCF decoding.

IEEE International Conference on Computer and Communications (ICCC)•Dec 10, 2021•2 citations
Polar code has lower coding and decoding requirements, linear complexity, and superior channel performance, so it is proven to be close to the Shannon limit for 5G communication. Successive cancellation (SC) is a polar code decoding method, but its performance has a lot of room for optimization, and flip methodology is one of its basic optimizations. Successive Cancellation Flip (SCF) has a good error correction capability. But due to the repetition of the SC decoder during computation, it has a very long latency. Moreover, SCF output is a hard decision, so it is not capable of soft input and soft output decoder. To allow SCF to be used in more decoding environments, the Hybrid SCF/SCAN proposed in this paper can freely select soft output and hard output, and the proposed architecture can reduce the problem of repeatedly computing SC decode.
There are two main algorithms, successive cancellation (SC) algorithm and brief propagation (BP) algorithm, for decoding polar code. The SC algorithm has better error-correcting performance and the BP algorithm has low latency. The hybrid BP-SC decoding combines these two decoding algorithms and achieves improvements. Furthermore, the successive cancellation flip (SCF) algorithm improves the error-correcting performance for the SC algorithm, but it has higher computation complexity and latency. Based on the hybrid BP-SC decoding, we proposed a hybrid BP-SC/SCF decoding for polar codes in this paper to further improve the error-correcting performance. The result shows our approach outperforms to frame error rates (FER) of the SC decoding and BP decoding at least 0.5-dB and outperforms hybrid BP-SC decoding by 0.2-dB to 0.4-dB. Compared with the SCF decoding, the hybrid BPSC/SCF decoding has a small degradation of FER in a highquality channel but it significantly reduces the average computation complexity.
By adopting successive cancellation list decoding (SCL), polar codes demonstrate competitive error correction performance over LDPC and Turbo codes. However, SCL decoding suffers from high computational complexity and long decoding latency, especially when the list size is very large. Successive cancellation flip (SCF), as another decoding algorithm that can achieve high error correction performance, has a complexity that is close to that of successive cancellation (SC) decoding. With the observation that SCL and SCF decoding are similar at giving more chances to inspect possible codewords simultaneously or sequentially, a novel hybrid decoder is proposed in this paper, which essentially combines the ideas of SCF and SCL decoders. Moreover, in order to compensate for the degradation of performance caused by the reduction of path splitting and further reduce the decoding latency, the convolutional polar codes are adopted with a designed bit-flipping set. Simulation results demonstrate that the proposed decoder achieves the reduction of decoding latency while attaining better performance than conventional CRC-aided SCL decoder.
When the code length is finite, the successive cancellation list (SCL) decoding of polar codes shows as good error-correction performance as low-density parity-check codes and turbo codes and it will be used in high-speed communications. However, since the hardware complexity of the SCL increases linearly as the size of the list increases, it is difficult to use the high-complexity SCL decoding for devices with limited resource such as IoT devices. The successive cancellation flip (SCF) decoding algorithm has been proposed to solve the problem of high hardware complexity and to enhance the error-correction performance of successive cancellation decoding. However, the conventional SCF decoding has high computational complexity. In this paper, we propose the interleaver-aided successive cancellation flip (ISCF) decoding to reduce the computational complexity. The computational complexity of the ISCF decoding is less by at least 32% than the conventional SCF decoding for error frame at Eb/N0=3.5dB.
Polar codes are a class of error-correcting codes that provably achieve the capacity of practical channels. The successive-cancellation flip (SCF) decoder is a low-complexity decoder that was proposed to improve the performance of the successive-cancellation (SC) decoder as an alternative to the high-complexity successive-cancellation list (SCL) decoder. The SCF decoder improves the error-correction performance of the SC decoder, but the variable execution time and the high worst-case execution time pose a challenge for the realization of receivers with fixed-time algorithms. The dynamic SCF (DSCF) variation of the SCF decoder further improves the error-correction performance but the challenge of decoding delay remains. In this work, we propose a simplified restart mechanism (SRM) that reduces the execution time of SCF and DSCF decoders through conditional restart of the additional trials from the second half of the codeword. We show that the proposed mechanism is able to improve the execution time characteristics of SCF and DSCF decoders while providing identical error-correction performance. For a DSCF decoder that can flip up to 3 simultaneous bits per decoding trial, the average execution time, the average additional execution time and the execution-time variance are reduced by approximately 31%, 37% and 57%, respectively. For this setup, the mechanism requires approximately 3.9% additional memory.
In this paper, we propose the threshold successive cancellation flip (Th-SCF) decoding algorithm for polar codes, which enhances the performance of the SC decoder while maintaining low complexity. Theoretical analysis reveals that Th-SCF asymptotically delays the first error position (FEP, the first part where the SC decoder fails) with probability 1, ensuring high decoding performance. Simulation results show that the Th-SCF algorithm achieves performance comparable to the dynamic SC flip (D-SCF) algorithm, but with a reduction in complexity by eliminating the need for sorting operations. A key contribution of this work is the rigorous theoretical framework supporting the Th-SCF algorithm, distinguishing it from existing SC flip (SCF) decoding methods. This theoretical foundation not only explains the performance improvements but also provides insights into the underlying mechanisms of flipping. The proposed Th-SCF algorithm demonstrates strong performance across a wide range of code lengths and rates, and its performance remains stable within a certain threshold range, indicating its practical applicability in real-world communication systems. These results offer valuable perspectives for the design of efficient flip decoding strategies in 5G and future networks.
Polar codes are the first error-correcting codes that achieve the Shannon limit under successive cancellation (SC) decoding when the code length is infinite. However, the error-correcting performance of SC decoding is mediocre for short and moderate code lengths. Dynamic successive cancellation flip (DSCF) decoding has been proposed that performs extra SC decoding trails with multi-bit flipping to improve the performance of short and moderate polar codes. The DSCF decoding suffers from high computational complexity and decoding latency since all information bits are tested when searching for the flipping candidates, which leads to intensive metric calculations. To reduce the search complexity of the DSCF, a method based on the critical set (CS) is proposed in this paper to narrow the search range and two types of special nodes, rate-0 nodes and repetition nodes, are incorporated for further complexity reduction. Simulation results show that the proposed method can achieve more than 70% reduction in calculations on metrics, and up to 22.79% reduction in calculations on nodes without performance loss compared to the original DSCF decoding.