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Modulating the Lasing Performance of the Quantum Dot-Cavity System by Adding a Resonant Driving Field

Chinese Physics Letters 2017年第1期34卷 115-119页

作者：秦利国王琴 Institute of Signal Processing and Transmission Nanjing University of Posts and TelecommunicationsNanjing 210003 Key Lab of Broadband Wireless Communication and Sensor Network Technology(Ministry of Education) Nanjing University of Posts and TelecommunicationsNanjing 210003

We propose a new scheme on modulating the lasing performance of a quantum dot-cavity system. Compared to the conventional above-band pump, in our new scheme an additional resonant driving field is applied on the quantum dot-cavity system. By employing the master equation theory and the Jaynes-Cummings model, we are able to study the interesting phenomenon of the coupling system. To compare the different behaviors between using our new scheme and the conventional method,we carry out investigatioin for both the 'good system'and 'more realistic system', characterizing several important parameters, such as the cavity population, exciton population and the second-order correlation function at zero time delay. Through numerical simulations,we demonstrate that for both the good system and more realistic system, their lasing regimes can be displaced into other regimes in the presence of a resonant driving field.

关键词： Modulating the Lasing Performance of the Quantum Dot-Cavity System by Adding a Resonant Driving Field

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Energy-Efficient Resource Allocation for wireless-Powered Backscatter communication networks

Energy-Efficient Resource Allocation for Wireless-Powered Ba...

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International Conference on communication Systems

作者： Bin Lyu Zhen Yang Feng Tian Guan Gui Key Laboratory of Ministry of Education in Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781538678657;9781538678640

In this paper, we investigate energy-efficient resource allocation in a wireless powered backscatter communication network (WPBCN), which consists of two types of wireless devices. To fully exploit the information transmission time, the two devices are supported to operate in different modes, i.e., the harvest-then-transmit (HTT) mode and backscatter communication (BackCom) mode, respectively. To improve the efficiency of wireless power transfer, energy beamforming technique is adopted at the PB. We formulate the system energy efficiency (EE) maximization problem by jointly optimizing the energy beamforming vector, power allocation, and time allocation. Since the formulated problem is non-convex, we employ variable substitutions, fractional programming theory, and semi-definite relaxation (SDR) to transform the non-convex problem into a convex problem. An algorithm is finally proposed to derive the optimal solution. Simulation results show that the proposed resource allocation scheme can improve the system EE.

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Asymmetric sending or not-sending twin-field quantum key distribution in practice

arXiv

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arXiv 2019年

作者： Zhou, Xing-Yu Zhang, Chun-Hui Zhang, Chun-Mei Wang, Qin Institute of quantum information and technology Nanjing University of Posts and Telecommunications Nanjing210003 China "Broadband Wireless Communication and Senser Network Technology" Key Lab of Ministry of Education NUPT Nanjing210003 China "Telecommunication and Networks" National Engineering Research Center NUPT Nanjing210003 China

Quantum key distribution (QKD) offers a secret way to share keys between legitimate users which is guaranteed by the law of quantum mechanics. Most recently, the limitation of transmission distance without quantum repeaters was broken through by twin-field QKD [Nature (London) 557, 400 (2018)]. Based on its main idea, sending or not-sending (SNS) QKD protocol was proposed [Phys. Rev. A 98, 062323 (2018)], which filled the remaining security loopholes and can tolerate large misalignment errors. In this paper, we give a more general model for SNS QKD, where the two legitimate users, Alice and Bob, can possess asymmetric quantum channels. By applying the method present in the work, the legitimate users can achieve dramatically increased key generation rate and transmission distance compared with utilizing the original symmetric protocol. Therefore, our present work represents a further step along the progress of practical QKD. Copyright © 2019, The Authors. All rights reserved.

关键词： Quantum cryptography

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Efficient passive measurement-device-independent quantum key distribution

arXiv

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arXiv 2019年

作者： Zhang, Chun-Hui Zhang, Chun-Mei Wang, Qin Institute of quantum information and technology Nanjing University of Posts and Telecommunications Nanjing210003 China "Broadband Wireless Communication and Senser Network Technology" Key Lab of Ministry of Education NUPT Nanjing210003 China "Telecommunication and Networks"National Engineering Research Center NUPT Nanjing210003 China

The measurement-device-independent quantum key distribution (MDI-QKD) possesses the highest security among all practical quantum key distribution protocols. However, existing multiintensity decoy-state methods may cause loopholes when modulating light intensities with practical devices. In this paper, we propose a passive decoy-state MDI-QKD protocol based on a novel structure of heralded single-photon sources. It does not need to modulate the light source into different intensities and thus can avoid leaking modulation information of decoy states to eavesdroppers, enhancing the security of practical MDI-QKD. Furthermore, by combining the passive decoy states and biased basis choices, our protocol can exhibit distinct advantages compared with state-of-the art MDI-QKD schemes even when the finite key-size effect is taken into account. Therefore, our present passive decoy-state MDI-QKD seems a promising candidate for practical implementation of quantum key distributions in the near future. Copyright © 2019, The Authors. All rights reserved.

关键词： Quantum cryptography

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Satellite-Terrestrial Spectrum Sensing Scheme Based on Cascaded FNN and FIS

Satellite-Terrestrial Spectrum Sensing Scheme Based on Casca...

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IEEE Globecom Workshops

作者： Yueyue Zhang Yunchi Shi Fei Shen Yihuan Pang Feng Yan Lianfeng Shen Shanghai Aerospace Electronic Technology Institute Shanghai China School of Information Science and Engineering Southeast University Jiangsu P. R. China Key Lab for Wireless Sensor Network and Communication Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences China

ISBN: (数字)9781728109602

ISBN: (纸本)9781728109619

Due to the frequency reuse in 5G enhanced satellite communications, advanced spectrum management would be acquired to improve the spectrum efficiency, with the interference mitigation caused by the frequency conflict in the manner of spectral sharing. To this end, cognitive radio (CR) has brought into the widespread attention, which aims at detection of spectrum holes by using the information collected from the secondary users (SUs). Specifically, considering the characteristics of satellite channels, the detection of spectrum holes would be more difficult in high dynamic situation. In this paper, we propose an efficient spectrum sensing scheme by taking advantage of the cooperation of satellites and base stations. Firstly, each base station (BS) receives the sensing information collected by its associated SUs. Then, a channel estimation algorithm based on fuzzy neutral network (FNN) is designed with the real-time sampling and historical data stored at BS. After that, the optimal probability of detection can be determined using fuzzy inference system (FIS) with the available sensing set. Additionally, the cooperative spectrum sensing results would be uploaded to the satellites, providing information for the further frequency allocation at the satellites' side. Finally, simulation results reveal the performance gain of the proposed algorithm in terms of the detection probability of spectrum hole.

关键词： sensors Satellite broadcasting Satellites Fuzzy neural networks Channel estimation 5G mobile communication

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Three-step three-party quantum secure direct communication

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中国科学（物理学力学天文学） 2018年第9期61卷 26-30页

作者： Shan-Shan Chen Lan Zhou Wei Zhong Yu-Bo Sheng Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing 210003 China College of Mathematics & Physics Nanjing University of Posts and Telecommunications Nanjing 210003 China Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and TelecommunicationsMinistry of Education Nanjing 210003 China

We propose a three-party quantum secure direct communication (QSDC) protocol with hyperentanglement in both spatial-mode and polarization degrees of *** secret message can be encoded independently with desired unitary operations in two degrees of *** this protocol,a party can synchronously obtain the other two parties' *** with previous three-party QSDC protocols,our protocol has several ***,the single photons in our protocol are only required to transmit for three *** advantage makes this protocol simple and ***,Alice and Bob can send different secret messages to Charlie,***,with hyperentanglement,this protocol has a higher information capacity than other protocols.

关键词： quantum communication quantum secure direct communication hyperentanglement

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Optical encryption scheme based on ghost imaging with disordered speckles

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Chinese Physics B 2017年第5期26卷 160-164页

作者：张玉东赵生妹 Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China

An optical encryption scheme based on a ghost imaging system with disordered speckles is proposed to obtain a higher security with a small key. In the scheme, Alice produces the random speckle patterns and obtains the detection results with the help of a computational ghost imaging（CGI） system. Then Alice permutes the order of the random speckle patterns and shares the permutation sequence as a secure key to the authorized users. With the secure key, Bob could recover the object with the principle of the CGI system, whereas, the unauthorized users could not obtain any information of the object. The numerical simulations and experimental results show that the proposed scheme is feasible with a small key, simultaneously,it has a higher security. When the eavesdropping ratio（ER） is less than 40%, the eavesdropper cannot acquire any useful information. Meanwhile, the authorized users could recover completely with the secure key.

关键词： ghost encryption secure speckle recover authorized disordered users reconstructed PSNR

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Multidimensional Speaker Information Recognition based on Proposed Baseline System 2

Multidimensional Speaker Information Recognition based on Pr...

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2017 IEEE 第2届先进信息技术,电子与自动化控制国际会议(IAEAC 2017)

作者： Shan Li Longting Xu Zhen Yang Broadband Wireless Communication and Sensor Network Technology Key Lab.Nanjing University of Posts and Telecommunications Institute for Infocomm Research ASTAR

Traditional speech-related identity recognition commonly pays attention to individual aspect of speech signals but in reality, the speech signals are made up of semantics, speaker dependent features,

ISBN: (纸本)9781467389808

Traditional speech-related identity recognition commonly pays attention to individual aspect of speech signals but in reality, the speech signals are made up of semantics, speaker dependent features,

关键词： Speech recognition Speech Feature extraction Support vector machines Emotion recognition Training Mel frequency cepstral coefficient

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Secure beamformer design for cognitive satellite terrestrial networks 4

Secure beamformer design for cognitive satellite terrestrial...

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4th IEEE International Conference on Computer and communications, ICCC 2018

作者： Yin, Chunyan Lin, Zhi Tao, Xiangshuai Ouyang, Jian Lin, Min Panagopoulos, Athanasios D. Ministry of Education Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing China College of Communications Engineering Army Engineering University of PLA Nanjing China Nanjing Institute of Telecommunication Technology Nanjing China School of Electrical and Computer Engineering National Technical University of Athens Zografou15780 Greece

ISBN: (纸本)9781538683392

This paper proposes a beamforming (BF) scheme based on multi-objective optimization (MOO) for a cognitive satellite-terrestrial network (CSTN), where the eavesdroppers (Eves) attempt to intercept the private message conveyed to an intended user. By considering that the maximization of achievable secrecy rate (ASR) and the minimization of transmit power can not be achieved simultanesouly, we adopt artificial noise (AN) and apply the weighted Tchebycheff approach to formulate a multi-object optimization problem. Then, by introducing several auxiliary variables, applying semidefinite programming (SDP) and means of Taylor approximation, the original nonconvex MOO problem is transformed into a convex one with a series of linear constraints, and the BF weight vector and AN vector can be obtained. Finally, simulation results are given to illustrate the tradeoff between the conflicting objectives and the superiority of the proposed algorithm in comparison with the commonly used schemes. © 2018 IEEE.

关键词： Beamforming

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Power allocation optimization in MC-NOMA systems for maximizing weighted sum-rate 24

Power allocation optimization in MC-NOMA systems for maximiz...

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24th Asia-Pacific Conference on communications, APCC 2018

作者： Chen, Ruilu Wang, Xiaoming Xu, Youyun School of Telecommunication and Information Engineering Nanjing Univ. of Posts and Telecom. Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing Univ. of Posts and Telecom. Nanjing China National Engineering Research Center of Comm. and Network Nanjing Univ. of Posts and Telecom. Nanjing China

ISBN: (纸本)9781538669280

In this paper, we investigate a power allocation scheme in downlink multi-carrier non-orthogonal multiple access (MC-NOMA) systems for maximizing weighted sum-rate. Taking user-priority into account, we add the weighting factors into the formulated optimization problem. Firstly, we give sufficient and necessary concavity conditions that should be satisfied by the proposed weighted sum-rate maximization problem. Then, for more generally non-concave case, we use a first order approximation to convert the optimization problem and provide an iterative power allocation algorithm to find the globally optimal solution. Simulation results show that our proposed algorithm is superior to orthogonal frequency division multiple access (OFDMA) scheme and average power allocation scheme. © 2018 IEEE.

关键词： Frequency division multiple access

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