Pulse Doppler(PD) fuze is widely used in current battlefield. However, with the threat of repeater jamming, especially digital radio frequency memory technology, the deficiency in the anti-repeater jamming of a tradit...Pulse Doppler(PD) fuze is widely used in current battlefield. However, with the threat of repeater jamming, especially digital radio frequency memory technology, the deficiency in the anti-repeater jamming of a traditional PD fuze increasingly emerges. Therefore, a repeater jamming suppression method for a PD fuze based on identity(ID) recognition and chaotic encryption is proposed. Every fuze has its own ID which is encrypted with different chaotic binary sequences in every pulse period of the transmitted signal. The thumbtack-shaped ambiguity function shows a good resolution and distance cutoff characteristic. The ability of anti-repeater jamming is emphatically analyzed, and the results at different signal-to-noise ratio(SNR) show a strong anti-repeater jamming ability and range resolution that the proposed method possesses. Furthermore, the anti-repeater jamming ability is influenced by processing gain, bit error rate(BER) and correlation function. The simulation result validates the theoretical analysis, it shows the proposed method can significantly improve the anti-repeater jamming ability of a PD fuze.展开更多
In the process of encoding and decoding,erasure codes over binary fields,which just need AND operations and XOR operations and therefore have a high computational efficiency,are widely used in various fields of inform...In the process of encoding and decoding,erasure codes over binary fields,which just need AND operations and XOR operations and therefore have a high computational efficiency,are widely used in various fields of information technology.A matrix decoding method is proposed in this paper.The method is a universal data reconstruction scheme for erasure codes over binary fields.Besides a pre-judgment that whether errors can be recovered,the method can rebuild sectors of loss data on a fault-tolerant storage system constructed by erasure codes for disk errors.Data reconstruction process of the new method has simple and clear steps,so it is beneficial for implementation of computer codes.And more,it can be applied to other non-binary fields easily,so it is expected that the method has an extensive application in the future.展开更多
A decoding algorithm based on revised syndromes to decode the binary (23,12,7) Golay code is presented. The algorithm strongly depends on the algebraic properties of the code. For the algorithm, the worst complexity i...A decoding algorithm based on revised syndromes to decode the binary (23,12,7) Golay code is presented. The algorithm strongly depends on the algebraic properties of the code. For the algorithm, the worst complexity is about 683 mod2 additions, which is less than that of the algorithms available for the code, the average complexity is approximately 319 mod2 additions, which is slightly more than that of Blaum’s algorithm for the code.展开更多
为了提高多元低密度奇偶校验（LDPC,low density parity-check）码符号翻转译码算法的性能并降低译码的复杂度,提出了基于平均概率和停止准则的多元LDPC码加权符号翻转译码（APSCWSF,average probability and stopping criterion weight...为了提高多元低密度奇偶校验（LDPC,low density parity-check）码符号翻转译码算法的性能并降低译码的复杂度,提出了基于平均概率和停止准则的多元LDPC码加权符号翻转译码（APSCWSF,average probability and stopping criterion weighted symbol flipping）算法。该算法将校验节点邻接符号节点的平均概率信息作为权重,使翻转函数更加有效,提高符号的翻转效率,进而改善译码性能。并且通过设置迭代停止准则进一步加快算法的收敛速度。仿真结果显示,在加性高斯白噪声信道下,误符号率为10-5时,相比WSF算法、NSCWSF算法（Osc=10）和NSCWSF算法（Osc=6）,APSCWSF算法（Osc=10）分别获得约0.68 d B、0.83 d B和0.96 d B的增益。同时,APSCWSF算法（Osc=6）的平均迭代次数也分别降低78.60%~79.32%、74.89%~75.95%和67.20%~70.80%。展开更多
空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准...空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准循环特性,在硬件上易于用移位寄存器实现,且可以根据PPM的调制阶数灵活构造多进制LDPC码,优化系统级联结构。仿真结果表明,在弱湍流信道下此类码具较好的误码性能和较低的错误平层。在SER=10-6时,相比于基于GF(29)的RS(511,305)码,码率为0.88的多进制LDPC码约有4.75 d B的净编码增益。展开更多
基金National Natural Science Foundation of China under Grant No. 61973037 and No. 61673066。
文摘Pulse Doppler(PD) fuze is widely used in current battlefield. However, with the threat of repeater jamming, especially digital radio frequency memory technology, the deficiency in the anti-repeater jamming of a traditional PD fuze increasingly emerges. Therefore, a repeater jamming suppression method for a PD fuze based on identity(ID) recognition and chaotic encryption is proposed. Every fuze has its own ID which is encrypted with different chaotic binary sequences in every pulse period of the transmitted signal. The thumbtack-shaped ambiguity function shows a good resolution and distance cutoff characteristic. The ability of anti-repeater jamming is emphatically analyzed, and the results at different signal-to-noise ratio(SNR) show a strong anti-repeater jamming ability and range resolution that the proposed method possesses. Furthermore, the anti-repeater jamming ability is influenced by processing gain, bit error rate(BER) and correlation function. The simulation result validates the theoretical analysis, it shows the proposed method can significantly improve the anti-repeater jamming ability of a PD fuze.
基金supported by the National Natural Science Foundation of China under Grant No.61501064Sichuan Provincial Science and Technology Project under Grant No.2016GZ0122
文摘In the process of encoding and decoding,erasure codes over binary fields,which just need AND operations and XOR operations and therefore have a high computational efficiency,are widely used in various fields of information technology.A matrix decoding method is proposed in this paper.The method is a universal data reconstruction scheme for erasure codes over binary fields.Besides a pre-judgment that whether errors can be recovered,the method can rebuild sectors of loss data on a fault-tolerant storage system constructed by erasure codes for disk errors.Data reconstruction process of the new method has simple and clear steps,so it is beneficial for implementation of computer codes.And more,it can be applied to other non-binary fields easily,so it is expected that the method has an extensive application in the future.
基金Supported by the National Natural Science Foundation of China
文摘A decoding algorithm based on revised syndromes to decode the binary (23,12,7) Golay code is presented. The algorithm strongly depends on the algebraic properties of the code. For the algorithm, the worst complexity is about 683 mod2 additions, which is less than that of the algorithms available for the code, the average complexity is approximately 319 mod2 additions, which is slightly more than that of Blaum’s algorithm for the code.
文摘为了提高多元低密度奇偶校验（LDPC,low density parity-check）码符号翻转译码算法的性能并降低译码的复杂度,提出了基于平均概率和停止准则的多元LDPC码加权符号翻转译码（APSCWSF,average probability and stopping criterion weighted symbol flipping）算法。该算法将校验节点邻接符号节点的平均概率信息作为权重,使翻转函数更加有效,提高符号的翻转效率,进而改善译码性能。并且通过设置迭代停止准则进一步加快算法的收敛速度。仿真结果显示,在加性高斯白噪声信道下,误符号率为10-5时,相比WSF算法、NSCWSF算法（Osc=10）和NSCWSF算法（Osc=6）,APSCWSF算法（Osc=10）分别获得约0.68 d B、0.83 d B和0.96 d B的增益。同时,APSCWSF算法（Osc=6）的平均迭代次数也分别降低78.60%~79.32%、74.89%~75.95%和67.20%~70.80%。
文摘空间光通信技术是传输高速语音图像等数据信息的重要手段,为了解决星地激光通信系统中大气湍流效应的影响问题,提出一种低译码复杂度的多进制低密度奇偶校验(LDPC)码结合脉冲位置调制(PPM)的传输方案。所构造的多进制LDPC码不仅具有准循环特性,在硬件上易于用移位寄存器实现,且可以根据PPM的调制阶数灵活构造多进制LDPC码,优化系统级联结构。仿真结果表明,在弱湍流信道下此类码具较好的误码性能和较低的错误平层。在SER=10-6时,相比于基于GF(29)的RS(511,305)码,码率为0.88的多进制LDPC码约有4.75 d B的净编码增益。
