In order to avoid the complexity of Gaussian modulation and the problem that the traditional point-to-point communication DM-CVQKD protocol cannot meet the demand for multi-user key sharing at the same time, we propos...In order to avoid the complexity of Gaussian modulation and the problem that the traditional point-to-point communication DM-CVQKD protocol cannot meet the demand for multi-user key sharing at the same time, we propose a multi-ring discrete modulation continuous variable quantum key sharing scheme(MR-DM-CVQSS). In this paper, we primarily compare single-ring and multi-ring M-symbol amplitude and phase-shift keying modulations. We analyze their asymptotic key rates against collective attacks and consider the security key rates under finite-size effects. Leveraging the characteristics of discrete modulation, we improve the quantum secret sharing scheme. Non-dealer participants only require simple phase shifters to complete quantum secret sharing. We also provide the general design of the MR-DM-CVQSS protocol.We conduct a comprehensive analysis of the improved protocol's performance, confirming that the enhancement through multi-ring M-PSK allows for longer-distance quantum key distribution. Additionally, it reduces the deployment complexity of the system, thereby increasing the practical value.展开更多
We propose a discrete-modulated continuous-variable measurement-device-independent quantum key distribution protocol over a fiber-to-water channel.Different from optical fibers,the underwater channel has more severe o...We propose a discrete-modulated continuous-variable measurement-device-independent quantum key distribution protocol over a fiber-to-water channel.Different from optical fibers,the underwater channel has more severe optical attenuation because of optical absorption and scattering,which reduces the maximum communication distance.To enhance the performance of the protocol,the photon subtraction operation is implemented at the modulator side.We carry out a performance simulation in two different kinds of seawater channel,and the result shows that the scheme with photon subtraction has a longer secure communication distance under certain conditions.展开更多
Establishing secure data communication necessitates secure key exchange over a public channel.Quantum key distribution(QKD),which leverages the principles of quantum physics,can achieve this with information-theoretic...Establishing secure data communication necessitates secure key exchange over a public channel.Quantum key distribution(QKD),which leverages the principles of quantum physics,can achieve this with information-theoretic security.The discrete modulated(DM)continuous variable(CV)QKD protocol,in particular,is a suitable candidate for large-scale deployment of quantum-safe communication due to its simplicity and compatibility with standard high-speed telecommunication technology.Here,we present the first experimental demonstration of a four-state DM CVQKD system,successfully generating composable finite-size keys,secure against collective attacks over a 20 km fiber channel with 2.3×10^(9) coherent quantum states,achieving a positive composable key rate of 11.04×10^(-3) bits/symbol.This accomplishment is enabled by using an advanced security proof,meticulously selecting its parameters,and the fast,stable operation of the system.Our results mark a significant step toward the large-scale deployment of practical,high-performance,cost-effective,and highly secure quantum key distribution networks using standard telecommunication components.展开更多
Space-vector modulation (SVM) is widely used in multilevel inverters because of its ability to improve DC bus utilization, reduce harmonic distortion, and enhance operational flexibility. However, the increasing compl...Space-vector modulation (SVM) is widely used in multilevel inverters because of its ability to improve DC bus utilization, reduce harmonic distortion, and enhance operational flexibility. However, the increasing complexity of multilevel inverter topologies, such as neutral-point clamped, cascaded H-bridge, and modular multilevel converters, presents challenges in terms of computational efficiency, neutral-point voltage balancing, and common-mode voltage suppression. A detailed review of SVM techniques is provided, including traditional methods and advanced variants such as carrier-based SVM, selective harmonic elimination SVM, and virtual SVM. Additionally, recent hybrid approaches that combine multiple strategies to address specific performance requirements are discussed. The findings highlight advancements in improving the modulation performance, reducing switching losses, and achieving better harmonic attenuation. A discussion of the future challenges and opportunities for multilevel inverter modulation strategies is concluded.展开更多
A new combined soft switching technique and a novel topology of aeronautical static inverter with high frequency pulse dc link are proposed in this paper, namely an electrical isolated converter can realize soft swi...A new combined soft switching technique and a novel topology of aeronautical static inverter with high frequency pulse dc link are proposed in this paper, namely an electrical isolated converter can realize soft switching of two stage cascade converters. It lays technical foundation for high power density, high efficiency and low cost aeronautical static inverter. The operation and design approach of this topology are carefully analyzed and studied. The validity of this topology is verified by simulation and test.展开更多
Sine Non-linear Chirp Keying(SNCK) is a kind of high-efficient modulation scheme, which provides a potential new beamforming method in communication and radar systems. It has been proved to have advantages in some par...Sine Non-linear Chirp Keying(SNCK) is a kind of high-efficient modulation scheme, which provides a potential new beamforming method in communication and radar systems. It has been proved to have advantages in some parameter estimation issues over conventional modulation schemes. In this paper, a novel transform termed as Discrete Sinusoidal Frequency Modulation transform(DSFMT) is proposed. Then, the DSFMT of SNCK signal is deduced and classified into three types, based on which, the time-bandwidth product is estimated by the proposed algorithm. Simulation results show that the noise has a signifi cant impact on the localization of the peak value and the time-bandwidth product can be estimated by using local ratio values when.展开更多
The major approaches to the Time-Domain Equalizer (TEQ) design in DMT systemsare summarized. After pointing out that the optimal design method of Maximum ShorteningSignal-to-Noise Ration (MSSNR) TEQ can't be real-...The major approaches to the Time-Domain Equalizer (TEQ) design in DMT systemsare summarized. After pointing out that the optimal design method of Maximum ShorteningSignal-to-Noise Ration (MSSNR) TEQ can't be real-time implemented by DSP, we present a suboptimalMSSNR TEQ design method, which reduces the computational complexity greatly by using a new method toestimate the optimal delay Δ and a proposed step-by-step algorithm to compute the TEQ taps. Theresults of simulations show the validity of the suboptimal method.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61971348 and 61201194)。
文摘In order to avoid the complexity of Gaussian modulation and the problem that the traditional point-to-point communication DM-CVQKD protocol cannot meet the demand for multi-user key sharing at the same time, we propose a multi-ring discrete modulation continuous variable quantum key sharing scheme(MR-DM-CVQSS). In this paper, we primarily compare single-ring and multi-ring M-symbol amplitude and phase-shift keying modulations. We analyze their asymptotic key rates against collective attacks and consider the security key rates under finite-size effects. Leveraging the characteristics of discrete modulation, we improve the quantum secret sharing scheme. Non-dealer participants only require simple phase shifters to complete quantum secret sharing. We also provide the general design of the MR-DM-CVQSS protocol.We conduct a comprehensive analysis of the improved protocol's performance, confirming that the enhancement through multi-ring M-PSK allows for longer-distance quantum key distribution. Additionally, it reduces the deployment complexity of the system, thereby increasing the practical value.
文摘We propose a discrete-modulated continuous-variable measurement-device-independent quantum key distribution protocol over a fiber-to-water channel.Different from optical fibers,the underwater channel has more severe optical attenuation because of optical absorption and scattering,which reduces the maximum communication distance.To enhance the performance of the protocol,the photon subtraction operation is implemented at the modulator side.We carry out a performance simulation in two different kinds of seawater channel,and the result shows that the scheme with photon subtraction has a longer secure communication distance under certain conditions.
基金funded within the QuantERA II Programme(project CVSTAR)that has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No 101017733Innovation Fund Denmark(IFD)under Grant Agreement No 731473+5 种基金the Austrian Research Promotion Agency(FFG),project number FO999891361from the European Union’s Digital Europe programme under Grant Agreement No 101091659(QCI.DK)from the European Union’s Horizon Europe research and innovation programme under the project“Quantum Security Networks Partnership”(QSNP,grant agreement no.101114043)A.A.E.H.,U.L.A.and T.G.acknowledge support from Innovation Fund Denmark(CryptQ,0175-00018A)the Danish National Research Foundation,Center for Macroscopic Quantum States(bigQ,DNRF142)A.A.E.H.,R.Z.and T.G.acknowledge funding from the Carlsberg Foundation,project CF21-0466.
文摘Establishing secure data communication necessitates secure key exchange over a public channel.Quantum key distribution(QKD),which leverages the principles of quantum physics,can achieve this with information-theoretic security.The discrete modulated(DM)continuous variable(CV)QKD protocol,in particular,is a suitable candidate for large-scale deployment of quantum-safe communication due to its simplicity and compatibility with standard high-speed telecommunication technology.Here,we present the first experimental demonstration of a four-state DM CVQKD system,successfully generating composable finite-size keys,secure against collective attacks over a 20 km fiber channel with 2.3×10^(9) coherent quantum states,achieving a positive composable key rate of 11.04×10^(-3) bits/symbol.This accomplishment is enabled by using an advanced security proof,meticulously selecting its parameters,and the fast,stable operation of the system.Our results mark a significant step toward the large-scale deployment of practical,high-performance,cost-effective,and highly secure quantum key distribution networks using standard telecommunication components.
文摘Space-vector modulation (SVM) is widely used in multilevel inverters because of its ability to improve DC bus utilization, reduce harmonic distortion, and enhance operational flexibility. However, the increasing complexity of multilevel inverter topologies, such as neutral-point clamped, cascaded H-bridge, and modular multilevel converters, presents challenges in terms of computational efficiency, neutral-point voltage balancing, and common-mode voltage suppression. A detailed review of SVM techniques is provided, including traditional methods and advanced variants such as carrier-based SVM, selective harmonic elimination SVM, and virtual SVM. Additionally, recent hybrid approaches that combine multiple strategies to address specific performance requirements are discussed. The findings highlight advancements in improving the modulation performance, reducing switching losses, and achieving better harmonic attenuation. A discussion of the future challenges and opportunities for multilevel inverter modulation strategies is concluded.
文摘A new combined soft switching technique and a novel topology of aeronautical static inverter with high frequency pulse dc link are proposed in this paper, namely an electrical isolated converter can realize soft switching of two stage cascade converters. It lays technical foundation for high power density, high efficiency and low cost aeronautical static inverter. The operation and design approach of this topology are carefully analyzed and studied. The validity of this topology is verified by simulation and test.
基金supported by Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory(KX152600015/ITD-U15006)National Natural Science Foundation of China(No.61401196)
文摘Sine Non-linear Chirp Keying(SNCK) is a kind of high-efficient modulation scheme, which provides a potential new beamforming method in communication and radar systems. It has been proved to have advantages in some parameter estimation issues over conventional modulation schemes. In this paper, a novel transform termed as Discrete Sinusoidal Frequency Modulation transform(DSFMT) is proposed. Then, the DSFMT of SNCK signal is deduced and classified into three types, based on which, the time-bandwidth product is estimated by the proposed algorithm. Simulation results show that the noise has a signifi cant impact on the localization of the peak value and the time-bandwidth product can be estimated by using local ratio values when.
文摘The major approaches to the Time-Domain Equalizer (TEQ) design in DMT systemsare summarized. After pointing out that the optimal design method of Maximum ShorteningSignal-to-Noise Ration (MSSNR) TEQ can't be real-time implemented by DSP, we present a suboptimalMSSNR TEQ design method, which reduces the computational complexity greatly by using a new method toestimate the optimal delay Δ and a proposed step-by-step algorithm to compute the TEQ taps. Theresults of simulations show the validity of the suboptimal method.
