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作者： Liu, Kang Wei, Jie Zhang, Chun-Mei Wang, Qin Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing210003 China

We present a new scheme for realizing passive decoy-state quantum key distribution with the SARG04 protocol. It is based on parametric down-conversion sources, and we do not need to modulate the pumping light into different intensities. By applying local-mode-splitting detections on Alice's side, legitimate users can obtain four different kinds of counting events on Bob's side, due to intrinsic correlations between photon pairs from parametric downconversion processes. In the new scheme, we do not need to modulate signal pulses into different intensities and can, thus, avoid introducing any intensity modulating uncertainty. As a result, quite precise estimations of singleor multi-photon-pulse contributions can be obtained, enabling better performance of the key generation rate and transmission distance compared with other existing SARG04 protocols, e.g., the four-intensity decoy-state method using either parametric down-conversion sources or weak coherent sources. Besides, through comparisons, we also find that the proposed new passive decoy-state SARG04 protocol can also show some superiority over the conventional three-intensity decoy-state BB84 protocol at long transmission distances under certain experimental conditions. © 2018 Optical Society of America.

关键词： Quantum cryptography

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Co-whitening of i-vectors for short and long duration speaker verification 19

Co-whitening of i-vectors for short and long duration speake...

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19th Annual Conference of the International Speech communication, INTERSPEECH 2018

作者： Xu, Longting Lee, Kong Aik Li, Haizhou Yang, Zhen Department of Electrical and Computer Engineering National University of Singapore Singapore Data Science Research Laboratories NEC Corporation Japan Broadband Wireless Communication and Sensor Network Technology Key Lab Nanjing University of Posts and Telecommunications China

An i-vector is a fixed-length and low-rank representation of a speech utterance. It has been used extensively in text-independent speaker verification. Ideally, speech utterances from the same speaker would map to an unique i-vector. However, this is not the case due to some intrinsic and extrinsic factors like physical condition of the speaker, channel difference, noise and notably the duration of speech utterances. In particular, we found that i-vectors extracted from short utterances exhibit larger variance than that of long utterances. To address the problem, we propose a co-whitening approach, taking into account the duration, while maximizing the correlation between the i-vectors of short and long duration. The proposed co-whitening method was derived based on canonical correlation analysis (CCA). Experimental results on NIST SRE 2010 show that co-whitening method is effective in compensating the duration mismatch, leading to a reduction of up to 13.07% in equal error rate (EER). © 2018 International Speech communication Association. All rights reserved.

关键词： Vectors

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Secrecy outage analysis of integrated satellite-terrestrial relay networks 24

Secrecy outage analysis of integrated satellite-terrestrial ...

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24th Asia-Pacific Conference on communications, APCC 2018

作者： Tao, Xiangshuai Huang, Qingquan Yin, Chunyan Cheng, Guoqiang Ouyang, Jian Liu, Xin College of Communications Engineering Army Engineering University of PLA Nanjing China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China Nanjing Institute of Telecommunication Technology Nanjing China

ISBN: (纸本)9781538669280

This paper addresses the secure transmission problem of an integrated satellite-terrestrial relay networks (ISTRN), where multiple malicious eavesdroppers attempt to overhear the confidential signals from the satellite to a terrestrial user. Here, the relay is employed with multiple antenna and the decode-and-forward protocol is used. By supposing that the perfect instantaneous channel state information (CSI) of satellite-relay link and the statistical CSI of relay-user and relay-eavesdropper links are available at the relay, an optimization problem is first formulated to maximize the secrecy rate of the ISTRN. Then, the secure transmission scheme is designed to solve the optimization problem and obtain the closed-form beamforming weight vector. To further insight the secrecy performance of the proposed scheme, we derive the analytical expressions of the secrecy outage probability (SOP) of the considered ISTRN, where the satellite-relay link undergoes the shadowed-Rician fading, and the links of relay to user as well as eavesdroppers undergo the correlated Rayleigh fading. Finally, numerical results are given to confirm the superiority of the proposed scheme and the validity of the SOP analysis. © 2018 IEEE.

关键词： Beamforming

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Heralded amplification of single-photon entanglement with polarization feature

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Frontiers of physics 2018年第5期13卷 241-249页

作者： Yu-Yu Jin Sheng-Xian Qin Hao Zu Lan Zhou Wei Zhong Yu-Bo Sheng School of Science Nanjing University of Posts and Telecommunications Nanjing 210003 China New Energy Technology Engineering Laboratory of Jiangsu Province Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

Heralded noiseless amplification is beneficial in overcoming transmission photon loss in a noisy quantum channel. We propose a single-photon-assisted heralded noiseless amplification protocol of the single- photon entanglement （SPE）, where the single-photon qubit has an arbitrary unknown polarization feature. We focus on both the complete and partial photon loss during the transmission process. After the amplification, the parties can recover the pure less-entangled SPE into a maximally entangled SPE and increase its fidelity. Moreover, the polarization feature of the single-photon qubit will be well preserved and not be leaked. Our protocol can be realized under our current experimental condition. Based on the features above, our protocol may be useful in the quantum secure communication schemes that encode information in the polarization degree of freedom of photons.

关键词： quantum communication single-photon entanglement quantum state amplification polarization feature

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An Improved Centroid Localization Algorithm Based on Virtual Beacon Nodes for WSNs 3

An Improved Centroid Localization Algorithm Based on Virtual...

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3rd IEEE International Conference on Cloud Computing and Internet of Things, CCIOT 2018

作者： Jiang, Rui Wu, Qian Xu, Youyun Nanjing University of Posts and Telecommunications Telecommunication and Networks National Engineering Nanjing Jiangsu210023 China Broadband Wireless Communication and Sensor Network Technology Key Lab of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing Jiangsu210023 China

ISBN: (纸本)9781538671412

According to the application of range-free localization technology for wireless sensor networks (WSNs), an improved centroid localization algorithm is proposed in the paper. In this methodology, the centroid of the space enclosed by connected beacon nodes is considered as a virtual beacon node. It can be proved that the coordinate of the centroid and the received signal strength indication (RSSI) between the unknown node and the centroid could be calculated. When the beacon node with the weakest RSSI is replaced by this virtual beacon node, the space enclosed by connected beacon nodes is reduced and the location precision can be improved. Monte Carlo tests validate that the proposed algorithm has strong robustness and can achieve a good performance of localization precision and coverage. © 2018 IEEE.

关键词： sensor nodes

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Author Correction: An Effective Way for Simulating Oceanic Turbulence Channel on the Beam Carrying Orbital Angular Momentum

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Scientific reports 2020年第1期10卷 1268页

作者： Sunxiang Pan Le Wang Wennai Wang Shengmei Zhao Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications(NUPT) Nanjing 210003 China. Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China. wangwn@***. Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications(NUPT) Nanjing 210003 China. zhaosm@***. Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China. zhaosm@***.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

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GRIDLESS TWO-DIMENSIONAL DOA ESTIMATION WITH L-SHAPED ARRAY BASED ON THE CROSS-COVARIANCE MATRIX

GRIDLESS TWO-DIMENSIONAL DOA ESTIMATION WITH L-SHAPED ARRAY ...

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IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Xiaohuan Wu Wei-Ping Zhu Jun Yan Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781538646595

The atomic norm minimization (ANM) has been successfully incorporated into the two-dimensional (2-D) direction-of-arrival (DOA) estimation problem for super-resolution. However, its computational workload might be unaffordable when the number of snapshots is large. In this paper, we propose two gridless methods for 2-D DOA estimation with L-shaped array based on the atomic norm to improve the computational efficiency. Firstly, by exploiting the cross-covariance matrix an ANM-based model has been proposed. We then prove that this model can be efficiently solved as a semi-definite programming (SDP). Secondly, a modified model has been presented to improve the estimation accuracy. It is shown that our proposed methods can be applied to both uniform and sparse L-shaped arrays and do not require any knowledge of the number of sources. Furthermore, since our methods greatly reduce the model size as compared to the conventional ANM method, and thus are much more efficient. Simulations results are provided to demonstrate the advantage of our methods.

关键词： 2-D DOA estimation L-shaped array atomic norm cross-covariance matrix

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Real-time Hand Tracking Using Kinect

Real-time Hand Tracking Using Kinect

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作者： Chenxuan Xi Jianxin Chen Chenxue Zhao Qicheng Pei Lizheng Liu Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications) Ministry of Education

Real-time hand tracking is fundamental to human gesture recognition. However, due to the huge computation, previous studies are either off-line or limited to given poses. In order to satisfy the requirement of real-time hand tracking, in this paper we propose a real time hand tracking method using Kinect. Firstly we extract the hand region from the depth image output from Kinect. Then we achieve the hand parameters. During the procedure of hand region extraction, we propose a cascade structure with recursive connected component algorithm to improve the efficiency and reserve connection relationships in 3D space. To determine the fingertips, we use the former 3D connections and geodesic distance over hand skeleton pixels to guarantee the accuracy and robustness, with acceptable loss. Experimental results show that our proposed solution can significantly improve the quality of real-time hand tracking.

关键词： Hand tracking fingertip tracking Kinect connected component analysis geodesic distance

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Multidimensional reconciliation protocol for continuous-variable quantum key agreement with polar coding

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中国科学（物理学力学天文学） 2018年第9期61卷 99-102页

作者： ShengMei Zhao ZhiGang Shen Hong Xiao Le Wang Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China Institute of Signal Processing Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China

Continuous-variable quantum key distribution (CVQKD) [1-7] allows two remote parties (Alice and Bob) to share a secret key,even in the presence of an eavesdropper (Eve) with unlimited computational power [8-17].While,a highly efficient reconciliation protocol [18-21] is crucial in a CVQKD system,which can not only extract the errorless secret keys,but also provide a promising way to achieve a long distance CVQKD at a low signal-to-noise ratio (SNR).There are some practical reconciliation protocols [18-21] for CVQKD systems,such as,sliced reconciliation protocol (SEC) [18],sign reconciliation protocol [19],and multidimensional reconciliation protocol (MR) [21].Compared with the others,MR utilized the algebraic properties of a multidimensional method,which did not require quantization or any other post-selection technique.

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A Node Localization Algorithm in WSNs Based on Iterative Estimation

A Node Localization Algorithm in WSNs Based on Iterative Est...

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IEEE Information technology and Mechatronics Engineering Conference (ITOEC)

作者： Rui Jiang Qian Wu Youyun Xu Broadband Wireless Communication and Sensor Network Technology Key Lab of Ministry of Education Nanjing University of Posts and Telecommunications Jiangsu China

ISBN: (纸本)9781538653746

According to the application of range-free measurement for wireless sensor networks (WSNs), a novel localization algorithm of nodes in based on iterative centroid estimation is proposed in the paper. First, we derive the centroid of the plane enclosed by the current connected beacon nodes as well as the received signal strength (RSSI) between target and beacon nodes. Then, we replace the farthest beacon node from the target node with the centroid node we derive in order to narrow the area of the plane enclosed by the connected beacon nodes and improve the location accuracy through multiple iterations. Judging from the simulation results, the proposed algorithm presents decent results of all indications and is thus eligible for localization in WSNs.

关键词： Wireless sensor networks Measurement errors Signal to noise ratio Mathematical model Classification algorithms Estimation Approximation algorithms

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