Semiconductor optical amplifier used as regenerator for degraded differential phase-shift keying signals

Phase and amplitude regeneration are necessary for degraded differential phase-shift keying communication sys- tems. This paper proposes a regenerator based on semiconductor optical amplifier for differential phase-shift keying signals. The key regeneration mechanism is theoretically analysed. The effectiveness of semiconductor optical amplifier based regenerator is demonstrated by comparing the bit error rate and eye diagrams before and after regeneration for 40-Cbit/s differential phase-shift keying 1080-km transmission systems. The results show that regeneration effects are very well. Bit error rate is tess than 10-12 with the regenerator.

Analysis of the differential-phase-shift-keying protocol in the quantum-key-distribution system

The analysis is based on the error rate and the secure communication rate as functions of distance for three quantum-key-distribution （QKD） protocols： the Bennett-Brassard 1984, the Bennett Brassard Mermin 1992, and the coherent differential-phase-shift keying （DPSK） protocols. We consider the secure communication rate of the DPSK protocol against an arbitrary individual attack, including the most commonly considered intercept-resend and photonnumber splitting attacks, and concluded that the simple and efficient differential-phase-shift-keying protocol allows for more than 200 km of secure communication distance with high communication rates.

Interactive Kalman Filtering for Differential and Gaussian Frequency Shift Keying Modulation with Application in Bluetooth

Some applications are constrained only to implement low cost receivers. In this case, designers are required to use less complex and non-expensive modulation techniques. Differential Quadrature Phase Shift Keying (DQPSK) and Gaussian Frequency Shift Keying (GFSK) can be non-coherently demodulated with simple algorithms. However, these types of demodulation are not robust and suffer from poor performance. This paper proposes a new method to enhance the performance of DQPSK and GFSK using Interactive Kalman Filtering (IKF) technique, in which a one Unscented Kalman Filter (UKF) and two Kalman Filters (KF) are coupled to optimize the demodulated signals. This method consists of simple but very effective algorithms without adding complexity to the demodulators comparing to other very complex methods. UKF is used in this method due to its superiority in approximating and estimating nonlinear systems and its ability to handle non-Gaussian noise environments. The proposed method has been validated by creating a MATLAB/SIMULINK Bluetooth system model, in which the IKF is integrated into the receiver, which implement both DQPSK and GFSK, and run simulation in Gaussian and Non-Gaussian noise environments. Results have shown the effectiveness of this method in optimizing the received signals, and that the UKF outperforms the Extended Kalman Filter (EKF).

Broad-Band All-Optical Wavelength Conversion of Differential Phase-Shift Keyed Signal Using an SOA-Based Nonlinear Polarization Switch

Broad-band all-optical wavelength conversion of differential phase-shift keyed （DPSK） signal is experimentally demonstrated. This scheme is composed of a one-bit delay interferometer demodulation stage followed by a semiconductor optical amplifier （SOA） based nonlinear polarization switch. A wavelength converter for the 10 G b/s DPSK signal is presented, which has a wide wavelength range of more than 30 nm. The converted signals experience small power penalties less than 1.4 dB compared with the original signal, at a bit error rate of 10-9. Additionally, the optical spectra, the measured waveforms and the open eye diagrams of the converted signals show a high quality wavelength conversion performance.

Influence of multi-photon pulses on practical differential-phase-shift quantum key distribution

The influence of multi-photon pulses on practical differcBtial-phase-shift quantum key distribution （DPS-Qt（D） is analysed. We have estimated the information which Eve obtained by PNS （photon-number splitting） attack and BS （beam splitting） attack. The result indicates that the PNS attack and BS attack will not limit the transmission distance as long as we select an appropriate mean photon number. Also, the maximum mean photon number under BS attack in practical DPS-QKD system and the set of practical assumptions about Eve＇s capabilities are presented.

Round-robin differential quadrature phase-shift quantum key distribution

Recently,a round-robin differential phase-shift（RRDPS） protocol was proposed[Nature 509,475（2014）],in which the amount of leakage is bounded without monitoring the signal disturbance.Introducing states of the phase-encoded Bennett-Brassard 1984 protocol（PE-BB84） to the RRDPS,this paper presents another quantum key distribution protocol called round-robin differential quadrature phase-shift（RRDQPS） quantum key distribution.Regarding a train of many pulses as a single packet,the sender modulates the phase of each pulse by one of {0,π/2,π,3π/2},then the receiver measures each packet with a Mach-Zehnder interferometer having a phase basis of 0 or π/2.The RRDQPS protocol can be implemented with essential similar hardware to the PE-BB84,so it has great compatibility with the current quantum system.Here we analyze the security of the RRDQPS protocol against the intercept-resend attack and the beam-splitting attack.Results show that the proposed protocol inherits the advantages arising from the simplicity of the RRDPS protocol and is more robust against these attacks than the original protocol.

Application of a Discrete Phase-Randomized Coherent State Source in Round-Robin Differential Phase-Shift Quantum Key Distribution

Recently, a novel kind of quantum key distribution called the round-robin differential phase-shift （RRDPS） protocol was proposed, which bounds the amount of leakage without monitoring signal disturbance. The protocol can be implemented by a weak coherent source. The security of this protocol with a simply characterized source has been proved. The application of a common phase shift can improve the secret key rate of the protocol. In practice, the randomized phase is discrete and the secret key rate is deviated from the continuous case. In this study, we analyze security of the RRDPS protocol with discrete-phase-randomized coherent state source and bound the secret key rate. We fix the length of each packet at 32 and 64, then simulate the secret key rates of the RRDPS protocol with discrete-phase randomization and continuous-phase randomization. Our simulation results show that the performance of the discrete-phase randomization case is close to the continuous counterpart with only a small number of discrete phases. The research is practically valuable for experimental implementation.

Passive round-robin differential-quadrature-phase-shift quantum key distribution scheme with untrusted detectors

In this paper, we proposed the scheme for a passive round-robin differential-phase-shift quantum key distribution（RRDPS-QKD） set-up based on the principle of Hong–Ou–Mandel interference. Our scheme requires two legitimate parties to prepare their signal state with two different non-orthogonal bases instead of single in original protocol. Incorporating this characteristic, we establish the level of security of our protocol under the intercept-resend attack and demonstrate its detector-flaw-immune feature. Furthermore, we show that our scheme not only inherits the merit of better tolerance of bit errors and finite-sized-key effects but can be implemented using hardware similar to the measurement device independent QKD（MDI-QKD）. This ensures good compatibility with the current commonly used quantum system.

Lower bound for the security of differential phase shift quantum key distribution against a one-pulse-attack

Quantum key distribution is the art of sharing secret keys between two distant parties, and has attracted a lot of attention due to its unconditional security. Compared with other quantum key distribution protocols, the differential phase shift quantum key distribution protocol has higher efficiency and simpler apparatus. Unfortunately, the uncondi- tional security of differential phase shift quantum key distribution has not been proved. Utilizing the sharp continuity of the von Neuman entropy and some basic inequalities, we estimate the upper bound for the eavesdropper Eve＇s infor- mation. We then prove the lower bound for the security of the differential phase shift quantum key distribution protocol against a one-pulse attack with Devatak-Winter＇s secret key rate formula.

双模三维索引调制差分混沌移位键控系统的设计及性能分析

针对传统差分混沌移位键控系统速率低、误码性能差的问题,提出了一种双模三维索引调制差分混沌移位键控系统。该系统利用时隙、正交码和顺序索引,在选中与未选中的时隙上均传输信息比特。在接收端,通过采用降噪技术,减小了噪声的方差,提升了系统误码性能。推导了在加性白高斯噪声信道和多径瑞利衰落信道下的比特差错率公式。仿真结果显示,与相似的混沌键控系统相比,所提系统具备更高的数据速率和更为优越的误码性能。

高速置换索引差分混沌移位键控通信系统

为了提高置换索引差分混沌移位键控系统的数据传输速率和能量效率,提出了高速置换索引差分混沌移位键控通信系统。该系统采用置换矩阵索引多元信息,并携带一个调制位。发射端将参考信号复制P次作为信息承载信号,通过希尔伯特变换,每个信息时隙中多传输N个用户的信息,将信号级联到正交频分复用系统进行正交载波调制,大大提高了系统的数据传输速率;同时推导了该系统在高斯白噪声信道和多径瑞利衰落信道下的误码率表达式。理论分析及仿真结果证明,该系统相比其他置换索引类系统具有高速率、低误码率的良好特性,有更好的应用前景。

江苏专精特新企业参与关键核心技术攻关现状及政策环境研究

专精特新企业持续关注细分领域的技术突破和创新,是中国经济高质量发展的微观基础。通过分析江苏专精特新企业参与关键核心技术攻关的现状,梳理国内各地支持专精特新企业参与关键核心技术攻关的相关政策,为进一步发挥江苏专精特新企业补链、固链、强链作用,破解“卡脖子”难题提供重要参考。

基于生物信息学和机器学习筛选类风湿关节炎关键基因

类风湿性关节炎(RA)是一种器官特异性自身免疫疾病,特征在于慢性滑膜炎和骨质侵蚀,其高致残率会对社会和个人造成严重影响,因此需要有效可靠的RA诊断标志物和治疗靶点。本研究从GEO数据库下载了表达谱数据集和单细胞测序数据集,以阐明RA中潜在的候选基因和途径。首先,利用单细胞测序数据注释了5类细胞簇,筛选出每个细胞簇与RA相关的基因4109个,进行了基因本体(GO)和京都基因和基因组百科全书(KEGG)途径富集分析。其次,利用生物信息学方法分析表达数据,共鉴定出677个与RA相关的基因,进行了差异表达基因的GSEA富集分析。最后,对差异表达基因(DEG)和每个簇的差异表达基因进行关联分析,再利用LASSO算法进一步分析,获得了6个关键基因,分别是IGLL5、AIM1、NKG7、PSMB9、ANKRD11和BIRC3,这6个基因在训练集与验证集的ROC曲线显示其在类风湿关节炎中具有良好的诊断性能。

针对电力线通信信道下脉冲噪声的鲁棒混沌传输系统优化设计综述

随着用户的剧增,现有的无线资源已经难以为继。因此,电力线通信(PLC)的重新启用引起了各大研究单位及工业界的关注。PLC由于信道环境复杂,现有处理方案复杂度及成本较高,因而导致其发展缓慢。其中针对脉冲噪声的研究工作最为广泛,如何在低成本情况下针对脉冲噪声实现数据传输的鲁棒性尤为重要。该文首先介绍PLC环境中几种主流噪声以及分类,而后描述具有低成本低复杂度的差分混沌键控(DCSK)及多元DCSK(MDCSK)调制技术。分别介绍与分析该系统在PLC中的特性,以及针对各种脉冲噪声种类存在的优势以及改进方式。其次该文将介绍一些相关编码调制新方案以便于提高带限环境下的传输质量。结果表明这些优化工作显著地改善了系统性能,针对PLC整体信道特性系统参数的调制及编码调制传输优化方案将成为未来工作的研究热点。

肥胖相关子宫内膜腺癌关键基因筛选研究

目的探讨肥胖相关子宫内膜腺癌的生物标志物,并进一步分析其在子宫内膜腺癌中的预后意义。方法在癌症基因组图谱(TCGA)数据库中检索407例子宫内膜腺瘤或腺癌患者的基因表达数据,在基因表达综合数据库中检索肥胖基因表达数据集GSE12050,筛选肥胖相关子宫内膜腺癌的差异基因和关键基因,对关键基因进行功能富集分析。结果对TCGA数据库中子宫内膜腺癌基因表达数据进行基因差异表达分析,获得差异基因5479个;对GSE12050数据集中肥胖基因表达数据进行差异分析,获得差异基因171个。GO功能富集分析显示,差异基因主要涉及NADP代谢过程、含胶原蛋白的细胞外基质和内肽酶活力等功能;KEGG通路富集分析显示,差异基因主要涉及谷胱甘肽代谢、碳代谢和戊糖磷酸等途径。肥胖相关子宫内膜腺癌发生、发展相关基因为COL11A1、DBI、EGFL6、SFRP1、FMO2等,其中COL11A1、DBI基因对子宫内膜腺癌的预后效果更准确。关键基因MANIA网络分析显示,肥胖相关子宫内膜腺癌关键基因涉及NADP代谢过程、蛋白质氧化、氧化还原酶活等功能。癌症组织DBI相关蛋白丰度表达量高于癌旁组织,差异有统计学意义(P<0.01)。子宫内膜腺癌组织DBI基因表达量高于癌旁组织,差异有统计学意义(P<0.01)。结论COL11A1和DBI基因在子宫内膜腺癌尤其是与肥胖相关的子宫内膜腺癌中发挥着重要作用,或许可以作为肥胖相关子宫内膜腺癌早期诊断、精准治疗、预测预后的指标。

一种时间反转的参考信号调制DCSK通信方案

针对DCSK系统信息传输速率低及安全性差的问题,提出一种时间反转参考信号调制DCSK(TR-RMDCSK)通信系统方案。该方案采用RM调制实现了在一个帧时隙传输两个比特,携带偶数信息比特的混沌信号既是信息信号,也是传输奇数信息比特的参考信号,将参考信号进行时间反转,消除了同一帧时隙信号间的相关性,提升了比特传输速率及信号保密性。推导了高斯信道下的理论误码率,并在高斯信道和莱斯信道下进行了性能仿真分析。结果表明,该方案在不牺牲传输速率的情况下改善了误码性能,提高了系统安全性。

LiCi算法的相关密钥不可能差分分析

不可能差分攻击是一种重要的密钥恢复攻击方法,它利用概率为0的不可能出现的差分特征过滤错误密钥,已被广泛应用于多种分组算法的分析.LiCi算法是2017年Patil等人提出的一种新轻量级分组密码算法,基于平衡Feistel结构,采用轻量级S盒和简单移位操作等新型轻量级分组密码的设计理念,通过较少的轮函数运算产生数量相对较大的活跃S盒,具有结构紧凑、能耗低、占用面积小等特性,非常适用于资源受限的环境.关于LiCi算法目前最好的分析结果为16轮差分分析和17轮不可能差分分析.为进一步研究LiCi算法抵抗不可能差分攻击的能力,构造了11轮不可能差分区分器,并向前扩展3轮,向后扩展3轮,结合S盒输入输出特征,使用不可能差分分析方法分析了17轮LiCi算法.分析的数据复杂度为2^(61.59),时间复杂度为2^(75.5),存储复杂度为2^(72.59).与已知结果相比,在攻击轮数相同的情况下,该攻击降低了数据复杂度和时间复杂度.同时结合密钥扩展算法的特点和轮函数特征,构造出3条16轮的相关密钥不可能差分区分器,从中选取一条向前扩展3轮,向后扩展2轮,结合S盒输入输出特征,并使用相关密钥与不可能差分复合的方法分析了21轮LiCi算法.分析的数据复杂度为2^(61.2),时间复杂度2^(68.05),存储复杂度为2^(75.2).由此说明21轮LiCi算法对相关密钥不可能差分密码分析是不免疫的.

几类密码算法的神经网络差分区分器的改进

为了进一步研究神经网络在密码分析方面的应用,利用深度残差网络和传统差分密码分析技术构造并改进了几类典型的轻量级分组密码算法的神经网络差分区分器。主要取得以下结果:①分别构造了4~7轮PRESENT、3轮KLEIN、7~9轮LBlock和7~10轮Simeck 32/64的神经网络差分区分器,并基于密码的分组结构分别进行了分析;②基于SPN结构分组密码的特点对PRESENT和KLEIN的神经网络差分区分器进行了改进,最多可提高约5.12%的准确率,并在对LBlock的神经网络差分区分器进行研究时验证得出这种改进方式不适用于Feistel结构的分组密码;③基于Simeck 32/64本身密码算法的特点对其神经网络差分区分器进行改进,提高了约2.3%的准确率。同时,将Simeck 32/64的改进方法与多面体差分分析进行结合,将已有的8轮和9轮Simeck 32/64多面体神经网络差分区分器的准确率提高了约1%和3.2%。最后,将实验中得到的3类神经网络差分区分器模型分别应用到11轮Simeck 32/64的最后一轮子密钥恢复攻击中,其中最佳的实验结果是在1000次攻击实验中以26.6的数据复杂度达到约99.4%的攻击成功率。

一种M进制短参考置换索引的差分混沌移位键控系统

为解决置换索引的差分混沌移位键控(PI-DCSK)通信系统存在能量效率低的问题,结合短参考技术,提出了一种M进制短参考置换索引的差分混沌移位键控(SR-PI-DCSK)系统。该系统将参考时隙的混沌序列缩短至小于半个符号周期,信息时隙将参考时隙的置换排列副本进行复制并拼接P次,在不增加PI-DCSK系统结构复杂度及维持相同的恢复比特信息所需能量的情况下,可以有效提高系统能量效率,同时提升系统的误比特率(BER)。然后,分析了SR-PIDCSK系统的能量效率,推导了其在多径瑞利衰落信道环境下的BER表达式,使用蒙特-卡罗模拟仿真验证了该理论推导的正确性。仿真结果表明,在同一条件下,所提出的系统与PI-DCSK系统相比具有更好的性能增益,这能为下一代物联网短距离通信应用提供一种混沌调制方案。

整合生物信息学和机器学习方法探究肥厚型心肌病自噬相关机制及鉴定潜在的关键基因

目的:自噬调节异常与肥厚型心肌病(hypertrophic cardiomyopathy,HCM)密切相关,然而其具体机制仍未阐明。本研究拟探究HCM自噬相关机制及鉴定潜在的关键基因。方法:对HCM患者和健康对照者(healthy controls,HC)的心肌组织转录谱数据进行生物信息学分析,包括自噬相关差异表达基因(differentially expressed genes,DEGs)的鉴定和富集分析,利用最小绝对收缩和选择算子(least absolute shrinkage and selection operator,LASSO)回归模型和支持向量机递归特征消除(support vector machine recursive feature elimination,SVM-RFE)分析来筛选关键基因。外部数据集验证关键基因的表达。绘制受试者操作特征(receiver operator characteristic,ROC)曲线评估关键基因的诊断效能。结果:通过比较HCM患者和HC的转录谱数据,并与自噬相关基因取交集,筛选出12个自噬相关DEGs。富集分析表明这些基因主要参与胃泌素信号通路、甘丙肽受体通路、蛋白质相互作用数据库中的白细胞介素-6和白细胞介素-7信号通路、蛋白质相互作用数据库中的激活蛋白1信号通路、1,25-二羟基维生素D3的非基因组作用和凋亡等。筛选出6个候选关键基因,即PRKCD、MYC、DDIT3、CAPN1、HGS和TMEM74。PRKCD、MYC和DDIT3在验证数据集中成功验证,且具备较好的诊断效能。结论:PRKCD、MYC和DDIT3可能是HCM自噬相关的关键基因。