For any odd prime p, a classification of all cyclic and negacyclic codes of length 8ps over Fpm are obtained, which establishes the algebra structures in term of specified polynomial generators of such codes. Among ot...For any odd prime p, a classification of all cyclic and negacyclic codes of length 8ps over Fpm are obtained, which establishes the algebra structures in term of specified polynomial generators of such codes. Among other results, all self-dual negacyclic codes of length 8ps are obtained, and the structures of α-constacyclic and β-constacyclic codes of length 8ps over Fpm are established.展开更多
In this article, we focus on cyclic and negacyclic codes of length 2p^s over the ring R = Fp^m ＋ uFp^m, where p is an odd prime. On the basis of the works of Dinh （in J.Algebra 324,940-950,2010）, we use the Chinese...In this article, we focus on cyclic and negacyclic codes of length 2p^s over the ring R = Fp^m ＋ uFp^m, where p is an odd prime. On the basis of the works of Dinh （in J.Algebra 324,940-950,2010）, we use the Chinese Remainder Theorem to establish the algebraic structure of cyclic and negacyclic codes of length 2p^s over the ring Fp^m ＋ uFp^m in terms of polynomial generators. Furthermore, we obtain the number of codewords in each of those cyclic and negacyclic codes.展开更多
In order to solve high encoding complexities of irregular low-density parity-check （LDPC） codes, a deterministic construction of irregular LDPC codes with low encoding complexities is proposed. The encoding algorith...In order to solve high encoding complexities of irregular low-density parity-check （LDPC） codes, a deterministic construction of irregular LDPC codes with low encoding complexities is proposed. The encoding algorithms are designed, whose complexities are linear equations of code length. The construction and encoding algorithms are derived from the effectively encoding characteristics of repeat-accumulate （RA） codes and masking technique. First, the new construction modifies parity-check matrices of RA codes to eliminate error floors of RA codes. Second, the new constructed parity-check matrices are based on Vandermonde matrices; this deterministic algebraic structure is easy for hardware implementation. Theoretic analysis and experimental results show that, at a bit-error rate of 10 × 10^-4, the new codes with lower encoding complexities outperform Mackay＇s random LDPC codes by 0.4-0.6 dB over an additive white Gauss noise （AWGN） channel.展开更多
随着6G通信研究的深入,卫星互联网作为空天地一体化网络的重要组成部分,对高吞吐量、高可靠性和低延时的需求推动了新型编码调制技术的发展。多级编码调制与混合自动重传请求技术的结合被认为是提升6G卫星互联网性能的重要方向。提出了...随着6G通信研究的深入,卫星互联网作为空天地一体化网络的重要组成部分,对高吞吐量、高可靠性和低延时的需求推动了新型编码调制技术的发展。多级编码调制与混合自动重传请求技术的结合被认为是提升6G卫星互联网性能的重要方向。提出了一种基于多级编码调制的增量冗余重传方案,旨在优化频谱效率并增强传输可靠性。针对传统研究中多级编码调制与增量冗余重传独立设计的局限性,通过灵活的分层重传策略,使各编码层均能有效应用增量冗余重传,充分利用编码增益、分集增益和能量增益。仿真结果表明,在256QAM(Quadrature Amplitude Modulation)调制下,该方案在码率0.667时可实现约6~8 d B的性能增益,显著提升系统可靠性与重传性能。展开更多
针对间歇采样转发干扰产生的假目标和目标高速运动产生的多普勒频移导致雷达脉压性能急剧下降的问题,提出一种高多普勒容限的线性调频离散相位编码(linear frequency modulation-discrete phase coding,LFM-DPC)复合调制相干波形集设计...针对间歇采样转发干扰产生的假目标和目标高速运动产生的多普勒频移导致雷达脉压性能急剧下降的问题,提出一种高多普勒容限的线性调频离散相位编码(linear frequency modulation-discrete phase coding,LFM-DPC)复合调制相干波形集设计方法。在一定多普勒频移范围内,以最小化未转发信号自模糊函数旁瓣能量以及未转发信号与转发信号互模糊函数能量建立优化模型,并设计一种基于KKT(Karush-Kuhn-Tucker)最优性条件的迭代算法对模型求解。仿真实验表明,相比于遗传算法和单一调制的LFM和DPC信号,基于KKT最优性条件的交替迭代优化算法优化的LFM-DPC波形集有更好的抗间歇采样转发干扰性能。展开更多
基金Supported by the Natural Science Foundation of Hubei Province(D20144401)the Natural Science Foundation of Hubei Polytechnic University(12xjz14A)
文摘For any odd prime p, a classification of all cyclic and negacyclic codes of length 8ps over Fpm are obtained, which establishes the algebra structures in term of specified polynomial generators of such codes. Among other results, all self-dual negacyclic codes of length 8ps are obtained, and the structures of α-constacyclic and β-constacyclic codes of length 8ps over Fpm are established.
基金supported by the Natural ScienceFoundation of Hubei Province(D2014401)the Natural Science Foundation of Hubei Polytechnic University(12xjz14A)
文摘In this article, we focus on cyclic and negacyclic codes of length 2p^s over the ring R = Fp^m ＋ uFp^m, where p is an odd prime. On the basis of the works of Dinh （in J.Algebra 324,940-950,2010）, we use the Chinese Remainder Theorem to establish the algebraic structure of cyclic and negacyclic codes of length 2p^s over the ring Fp^m ＋ uFp^m in terms of polynomial generators. Furthermore, we obtain the number of codewords in each of those cyclic and negacyclic codes.
基金Supported by the National Natural Science Foundation of China(60496315, 60572050)
文摘In order to solve high encoding complexities of irregular low-density parity-check （LDPC） codes, a deterministic construction of irregular LDPC codes with low encoding complexities is proposed. The encoding algorithms are designed, whose complexities are linear equations of code length. The construction and encoding algorithms are derived from the effectively encoding characteristics of repeat-accumulate （RA） codes and masking technique. First, the new construction modifies parity-check matrices of RA codes to eliminate error floors of RA codes. Second, the new constructed parity-check matrices are based on Vandermonde matrices; this deterministic algebraic structure is easy for hardware implementation. Theoretic analysis and experimental results show that, at a bit-error rate of 10 × 10^-4, the new codes with lower encoding complexities outperform Mackay＇s random LDPC codes by 0.4-0.6 dB over an additive white Gauss noise （AWGN） channel.
文摘随着6G通信研究的深入,卫星互联网作为空天地一体化网络的重要组成部分,对高吞吐量、高可靠性和低延时的需求推动了新型编码调制技术的发展。多级编码调制与混合自动重传请求技术的结合被认为是提升6G卫星互联网性能的重要方向。提出了一种基于多级编码调制的增量冗余重传方案,旨在优化频谱效率并增强传输可靠性。针对传统研究中多级编码调制与增量冗余重传独立设计的局限性,通过灵活的分层重传策略,使各编码层均能有效应用增量冗余重传,充分利用编码增益、分集增益和能量增益。仿真结果表明,在256QAM(Quadrature Amplitude Modulation)调制下,该方案在码率0.667时可实现约6~8 d B的性能增益,显著提升系统可靠性与重传性能。
文摘针对间歇采样转发干扰产生的假目标和目标高速运动产生的多普勒频移导致雷达脉压性能急剧下降的问题,提出一种高多普勒容限的线性调频离散相位编码(linear frequency modulation-discrete phase coding,LFM-DPC)复合调制相干波形集设计方法。在一定多普勒频移范围内,以最小化未转发信号自模糊函数旁瓣能量以及未转发信号与转发信号互模糊函数能量建立优化模型,并设计一种基于KKT(Karush-Kuhn-Tucker)最优性条件的迭代算法对模型求解。仿真实验表明,相比于遗传算法和单一调制的LFM和DPC信号,基于KKT最优性条件的交替迭代优化算法优化的LFM-DPC波形集有更好的抗间歇采样转发干扰性能。
