Implementing check node(CN)update based on the minimum value(MV)and second MV of incoming message magnitudes is crucial for Min-Sum Algorithms(MSAs).In the category of bit-serial implementations,existing schemes suffe...Implementing check node(CN)update based on the minimum value(MV)and second MV of incoming message magnitudes is crucial for Min-Sum Algorithms(MSAs).In the category of bit-serial implementations,existing schemes suffer from decoding performance degradation,large hardware areas,and/or long latency.In this paper,we propose two efficient CN update functions based on the MV and an approximate second MV,and design bit-serial architectures to implement them.Simulation results show that our functions exhibit the minimum decoding performance degradation compared to the existing functions using approximate second MVs.Moreover,the applicationspecific integrated circuits(ASIC)implementation results demonstrate the advantages of our architectures in terms of area,latency,etc.展开更多
Aiming at the poor performance of the parity check(PC) aided adaptive successive cancellation list(PC-ASCL) decoding algorithm because the PC code in the polar code can only verify odd errors, an optimized parity chec...Aiming at the poor performance of the parity check(PC) aided adaptive successive cancellation list(PC-ASCL) decoding algorithm because the PC code in the polar code can only verify odd errors, an optimized parity check(OPC) code which can verify all odd errors as well as the half even errors is proposed. The OPC code is used to improve the PC-ASCL decoding algorithm, thus an OPC aided ASCL(OPC-ASCL) decoding algorithm is proposed. In the coding stage, the algorithm divides the information sequence into multiple segments, and places an OPC code at the end of each segment to verify the current information sequence, and places a cyclic redundancy check code at the end of the entire information sequence to verify the entire information sequence. In the decoding stage, the algorithm uses the OPC-ASCL decoder to decode. Simulation results show that compared to the PC-ASCL decoding algorithm, the OPC-ASCL decoding algorithm can reduce the complexity and obtain the certain performance gain.展开更多
Blind encoder recognition methods have drawn much research interest in recent years,as they can play an important role in non-cooperative scenarios.This paper proposes an open-set blind recognition method for nonbinar...Blind encoder recognition methods have drawn much research interest in recent years,as they can play an important role in non-cooperative scenarios.This paper proposes an open-set blind recognition method for nonbinary Low-Density Parity-Check(LDPC)codes with high performance.We derive the principle of obtaining a non-binary Parity-Check Matrix(PCM)from the received signal and further apply the Gauss-Jordan Column Elimination(GJCE)over GF(q).An iterative process involving GJCE,LDPC decoding,and PCM sparsification is applied in our proposed method.The proposed symbol-level blind recognition is shown to perform much better than the bit-level one.Experimental results demonstrate that our proposed method can completely reconstruct the PCMs at a bit error rate of 0.4%for the moderate-length non-binary LDPC codes.展开更多
Blind recognition of low-density paritycheck(LDPC)codes has gradually attracted more attention with the development of military and civil communications.However,in the case of the paritycheck matrices with relatively ...Blind recognition of low-density paritycheck(LDPC)codes has gradually attracted more attention with the development of military and civil communications.However,in the case of the paritycheck matrices with relatively high row weights,the existing blind recognition algorithms based on a candidate set generally perform worse.In this paper,we propose a blind recognition method for LDPC codes,called as tangent function assisted least square(TLS)method,which improves recognition performances by constructing a new cost function.To characterize the constraint degree among received vectors and paritycheck vectors,a feature function based on tangent function is constructed in the proposed algorithm.A cost function based on least square method is also established according to the feature function values satisfying the parity-check relationship.Moreover,the minimum average value in TLS is obtained on the candidate set.Numerical analysis and simulation results show that recognition performances of TLS algorithm are consistent with theoretical results.Compared with existing algorithms,the proposed method possesses better recognition performances.展开更多
Large Language Models(LLMs)are increasingly being used to generate source code.However,a substantial proportion of their output contains security vulnerabilities.Existing defenses typically apply uniform analysis to a...Large Language Models(LLMs)are increasingly being used to generate source code.However,a substantial proportion of their output contains security vulnerabilities.Existing defenses typically apply uniform analysis to all code fragments,irrespective of their risk profiles.This study presents RAVE-Code,a three-layer framework that calibrates the verification effort based on the risk associated with each detected weakness.The Detection layer employs Bandit for pattern-based static analysis,annotating findings with their respective Common Weakness Enumeration(CWE)classes.The Risk Scoring layer calculates a composite risk score for each weakness instance by integrating the Common Vulnerability Scoring System(CVSS)severity,the prevalence of CWEs in AI-generated code,and actual exploitability data.The Verification layer directs each code fragment to an appropriate depth of Bounded Model Checking(BMC)using the Efficient SMT-Based Bounded Model Checker(ESBMC),with solver parameters customized for each CWE class.The framework is evaluated on three public benchmarks.On SecurityEval,Bandit identifies 28.5%of vulnerabilities with zero false positives,establishing a baseline for static analysis coverage.On FormAI,RAVE-Code achieves a detection rate of 86.0%(F1=0.909),compared to 73.8%(F1=0.834)for uniform verification,and uniquely detects 41 vulnerabilities that uniform analysis misses.Because FormAI’s labels are based on ESBMC,these results show how consistent two ESBMC configurations rather than agreement with an independent standard.On the Juliet Test Suite,which provides structurally independent ground truth,RAVE-Code achieves a detection rate of 57.3%(F1=0.614)compared to 40.8%(F1=0.479),detecting a total of 104 vulnerabilities.Applying all flags uniformly results in a detection rate 18.8 percentage points lower than the proposed per-CWE tailoring.This indicates that detection gains arise from routing rather than flag selection.展开更多
Space laser communication(SLC)is an emerging technology to support high-throughput data transmissions in space networks.In this paper,to guarantee the reliability of high-speed SLC links,we aim at practical implementa...Space laser communication(SLC)is an emerging technology to support high-throughput data transmissions in space networks.In this paper,to guarantee the reliability of high-speed SLC links,we aim at practical implementation of low-density paritycheck(LDPC)decoding under resource-restricted space platforms.Particularly,due to the supply restriction and cost issues of high-speed on-board devices such as analog-to-digital converters(ADCs),the input of LDPC decoding will be usually constrained by hard-decision channel output.To tackle this challenge,density-evolution-based theoretical analysis is firstly performed to identify the cause of performance degradation in the conventional binaryinitialized iterative decoding(BIID)algorithm.Then,a computation-efficient decoding algorithm named multiary-initialized iterative decoding with early termination(MIID-ET)is proposed,which improves the error-correcting performance and computation efficiency by using a reliability-based initialization method and a threshold-based decoding termination rule.Finally,numerical simulations are conducted on example codes of rates 7/8 and 1/2 to evaluate the performance of different LDPC decoding algorithms,where the proposed MIID-ET outperforms the BIID with a coding gain of 0.38 dB and variable node calculation saving of 37%.With this advantage,the proposed MIID-ET can notably reduce LDPC decoder’s hardware implementation complexity under the same bit error rate performance,which successfully doubles the total throughput to 10 Gbps on a single-chip FPGA.展开更多
This paper proposes a genetic optimization method for the construction of non-binary quasi-cyclic low-density parity-check(NB-QC-LDPC)codes with short block lengths.In our scheme,the initial template base matrices and...This paper proposes a genetic optimization method for the construction of non-binary quasi-cyclic low-density parity-check(NB-QC-LDPC)codes with short block lengths.In our scheme,the initial template base matrices and the corresponding non-binary replacement matrices are constructed by the progressive edge growth algorithm and randomly generated,respectively.The genetic algorithm is then utilized to optimize the base matrices and the replacement ones.The simulation results show that the NB-QC-LDPC codes constructed by the proposed method achieve better decoding performance and lower implementation complexity compared to the existing NB-LDPC codes such as consultative committee for space data system and Bei Dou satellite navigation system.展开更多
In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are de...In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are derived by permuting the matrices of the corresponding RC-LDPC block codes,are systematic and have maximum encoding memory.Simulation results show that the proposed RC-LDPC convolutional codes with belief propagation(BP) decoding collectively offer a steady improvement on performance compared with the block counterparts over the binary-input additive white Gaussian noise channels(BI-AWGNCs).展开更多
The progressive edge-growth(PEG)al-gorithm is a general method to construct short low-density parity-check(LDPC)codes and it is a greedy method to place each edge with large girths.In order to improve the performance ...The progressive edge-growth(PEG)al-gorithm is a general method to construct short low-density parity-check(LDPC)codes and it is a greedy method to place each edge with large girths.In order to improve the performance of LDPC codes,many im-proved PEG(IPEG)algorithms employ multi metrics to select surviving edges in turn.In this paper,the pro-posed edges metric(EM)based on message-passing algorithm(MPA)is introduced to PEG algorithm and the proposed EM constrained PEG(EM-PEG)algo-rithm mainly considers the independence of message passing from different nodes in Tanner graph.The numerical results show that our EM-PEG algorithm brings better bit error rate(BER)performance gains to LDPC codes than the traditional PEG algorithm and the powerful multi-edge multi-metric constrained PEG algorithm(MM-PEGA)proposed recently.In ad-dition,the multi-edge EM constrained PEG(M-EM-PEG)algorithm which adopts multi-edge EM may fur-ther improve the BER performance.展开更多
针对可见光信道中的干扰较强,且现阶段OCC(Optical Camera Communication)系统的编码技术纠错性能不足,造成OCC系统可靠性降低的问题,提出了一种面向OCC系统的QC-LDPC(Quasi-Cyclic Low Density Parity Check Code)编译码算法。根据OCC...针对可见光信道中的干扰较强,且现阶段OCC(Optical Camera Communication)系统的编码技术纠错性能不足,造成OCC系统可靠性降低的问题,提出了一种面向OCC系统的QC-LDPC(Quasi-Cyclic Low Density Parity Check Code)编译码算法。根据OCC系统的结构特点以及信道链路特性,确定具有结构化设计和低复杂度译码特性的QC-LDPC码作为纠错码型,采用快速编码算法减小编码过程的运算复杂度;结合归一化最小和算法和分层译码算法的各自特点提出了一种改进的L-MS(Layer-Min Sum)译码算法。OCC系统实验平台测试结果表明,在室内环境通信场景下,OCC系统的误码率为3.16×10-6,通信速率为2850.4 bit/s;在室外环境通信场景下,OCC系统的误码率为9.07×10-6,通信速率为2797.9 bit/s,在保证低误码率的同时,兼顾了数据的传输速率。展开更多
基金supported by National Natural Science Foundation of China(NSFC)under Grant 62571455,Grant 62371401,and Grant 62331002supported by the SingaporeMinistry of Education Academic Research Fund Tier 2 T2EP50221-0036.
摘要Implementing check node(CN)update based on the minimum value(MV)and second MV of incoming message magnitudes is crucial for Min-Sum Algorithms(MSAs).In the category of bit-serial implementations,existing schemes suffer from decoding performance degradation,large hardware areas,and/or long latency.In this paper,we propose two efficient CN update functions based on the MV and an approximate second MV,and design bit-serial architectures to implement them.Simulation results show that our functions exhibit the minimum decoding performance degradation compared to the existing functions using approximate second MVs.Moreover,the applicationspecific integrated circuits(ASIC)implementation results demonstrate the advantages of our architectures in terms of area,latency,etc.
基金supported by the National Natural Science Foundation of China(Nos.U21A20447 and 61971079)。
摘要Aiming at the poor performance of the parity check(PC) aided adaptive successive cancellation list(PC-ASCL) decoding algorithm because the PC code in the polar code can only verify odd errors, an optimized parity check(OPC) code which can verify all odd errors as well as the half even errors is proposed. The OPC code is used to improve the PC-ASCL decoding algorithm, thus an OPC aided ASCL(OPC-ASCL) decoding algorithm is proposed. In the coding stage, the algorithm divides the information sequence into multiple segments, and places an OPC code at the end of each segment to verify the current information sequence, and places a cyclic redundancy check code at the end of the entire information sequence to verify the entire information sequence. In the decoding stage, the algorithm uses the OPC-ASCL decoder to decode. Simulation results show that compared to the PC-ASCL decoding algorithm, the OPC-ASCL decoding algorithm can reduce the complexity and obtain the certain performance gain.
基金supported in part by the National Natural Science Foundation of China under Research Grant 62331002.
摘要Blind encoder recognition methods have drawn much research interest in recent years,as they can play an important role in non-cooperative scenarios.This paper proposes an open-set blind recognition method for nonbinary Low-Density Parity-Check(LDPC)codes with high performance.We derive the principle of obtaining a non-binary Parity-Check Matrix(PCM)from the received signal and further apply the Gauss-Jordan Column Elimination(GJCE)over GF(q).An iterative process involving GJCE,LDPC decoding,and PCM sparsification is applied in our proposed method.The proposed symbol-level blind recognition is shown to perform much better than the bit-level one.Experimental results demonstrate that our proposed method can completely reconstruct the PCMs at a bit error rate of 0.4%for the moderate-length non-binary LDPC codes.
基金Fundamental Research Funds for the Central Universities under Grant 3072025YC0802the National Natural Science Foundation of China under Grant 62001138Heilongjiang Provincial Natural Science Foundation of China under Grant LH2021F009。
摘要Blind recognition of low-density paritycheck(LDPC)codes has gradually attracted more attention with the development of military and civil communications.However,in the case of the paritycheck matrices with relatively high row weights,the existing blind recognition algorithms based on a candidate set generally perform worse.In this paper,we propose a blind recognition method for LDPC codes,called as tangent function assisted least square(TLS)method,which improves recognition performances by constructing a new cost function.To characterize the constraint degree among received vectors and paritycheck vectors,a feature function based on tangent function is constructed in the proposed algorithm.A cost function based on least square method is also established according to the feature function values satisfying the parity-check relationship.Moreover,the minimum average value in TLS is obtained on the candidate set.Numerical analysis and simulation results show that recognition performances of TLS algorithm are consistent with theoretical results.Compared with existing algorithms,the proposed method possesses better recognition performances.
基金funded by the Deanship of Graduate Studies and Scientific Research at Najran University under the Consortium Funding Program(grant code NU/CPL/SERC/14/1918-1).
摘要Large Language Models(LLMs)are increasingly being used to generate source code.However,a substantial proportion of their output contains security vulnerabilities.Existing defenses typically apply uniform analysis to all code fragments,irrespective of their risk profiles.This study presents RAVE-Code,a three-layer framework that calibrates the verification effort based on the risk associated with each detected weakness.The Detection layer employs Bandit for pattern-based static analysis,annotating findings with their respective Common Weakness Enumeration(CWE)classes.The Risk Scoring layer calculates a composite risk score for each weakness instance by integrating the Common Vulnerability Scoring System(CVSS)severity,the prevalence of CWEs in AI-generated code,and actual exploitability data.The Verification layer directs each code fragment to an appropriate depth of Bounded Model Checking(BMC)using the Efficient SMT-Based Bounded Model Checker(ESBMC),with solver parameters customized for each CWE class.The framework is evaluated on three public benchmarks.On SecurityEval,Bandit identifies 28.5%of vulnerabilities with zero false positives,establishing a baseline for static analysis coverage.On FormAI,RAVE-Code achieves a detection rate of 86.0%(F1=0.909),compared to 73.8%(F1=0.834)for uniform verification,and uniquely detects 41 vulnerabilities that uniform analysis misses.Because FormAI’s labels are based on ESBMC,these results show how consistent two ESBMC configurations rather than agreement with an independent standard.On the Juliet Test Suite,which provides structurally independent ground truth,RAVE-Code achieves a detection rate of 57.3%(F1=0.614)compared to 40.8%(F1=0.479),detecting a total of 104 vulnerabilities.Applying all flags uniformly results in a detection rate 18.8 percentage points lower than the proposed per-CWE tailoring.This indicates that detection gains arise from routing rather than flag selection.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1005000)the National Natural Science Foundation of China(Grant No.62101308 and 62025110).
摘要Space laser communication(SLC)is an emerging technology to support high-throughput data transmissions in space networks.In this paper,to guarantee the reliability of high-speed SLC links,we aim at practical implementation of low-density paritycheck(LDPC)decoding under resource-restricted space platforms.Particularly,due to the supply restriction and cost issues of high-speed on-board devices such as analog-to-digital converters(ADCs),the input of LDPC decoding will be usually constrained by hard-decision channel output.To tackle this challenge,density-evolution-based theoretical analysis is firstly performed to identify the cause of performance degradation in the conventional binaryinitialized iterative decoding(BIID)algorithm.Then,a computation-efficient decoding algorithm named multiary-initialized iterative decoding with early termination(MIID-ET)is proposed,which improves the error-correcting performance and computation efficiency by using a reliability-based initialization method and a threshold-based decoding termination rule.Finally,numerical simulations are conducted on example codes of rates 7/8 and 1/2 to evaluate the performance of different LDPC decoding algorithms,where the proposed MIID-ET outperforms the BIID with a coding gain of 0.38 dB and variable node calculation saving of 37%.With this advantage,the proposed MIID-ET can notably reduce LDPC decoder’s hardware implementation complexity under the same bit error rate performance,which successfully doubles the total throughput to 10 Gbps on a single-chip FPGA.
基金supported by the National Natural Science Foundation of China under Grants 62331002。
摘要This paper proposes a genetic optimization method for the construction of non-binary quasi-cyclic low-density parity-check(NB-QC-LDPC)codes with short block lengths.In our scheme,the initial template base matrices and the corresponding non-binary replacement matrices are constructed by the progressive edge growth algorithm and randomly generated,respectively.The genetic algorithm is then utilized to optimize the base matrices and the replacement ones.The simulation results show that the NB-QC-LDPC codes constructed by the proposed method achieve better decoding performance and lower implementation complexity compared to the existing NB-LDPC codes such as consultative committee for space data system and Bei Dou satellite navigation system.
基金the National Natural Science Foundation of China(Nos.61401164,61471131 and 61201145)the Natural Science Foundation of Guangdong Province(No.2014A030310308)
摘要In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are derived by permuting the matrices of the corresponding RC-LDPC block codes,are systematic and have maximum encoding memory.Simulation results show that the proposed RC-LDPC convolutional codes with belief propagation(BP) decoding collectively offer a steady improvement on performance compared with the block counterparts over the binary-input additive white Gaussian noise channels(BI-AWGNCs).
摘要The progressive edge-growth(PEG)al-gorithm is a general method to construct short low-density parity-check(LDPC)codes and it is a greedy method to place each edge with large girths.In order to improve the performance of LDPC codes,many im-proved PEG(IPEG)algorithms employ multi metrics to select surviving edges in turn.In this paper,the pro-posed edges metric(EM)based on message-passing algorithm(MPA)is introduced to PEG algorithm and the proposed EM constrained PEG(EM-PEG)algo-rithm mainly considers the independence of message passing from different nodes in Tanner graph.The numerical results show that our EM-PEG algorithm brings better bit error rate(BER)performance gains to LDPC codes than the traditional PEG algorithm and the powerful multi-edge multi-metric constrained PEG algorithm(MM-PEGA)proposed recently.In ad-dition,the multi-edge EM constrained PEG(M-EM-PEG)algorithm which adopts multi-edge EM may fur-ther improve the BER performance.