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A New Approach to Multi-user Detection in DS-CDMA

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High Technology Letters 2001年第1期7卷 27-30页

作者： Tu Zhenyu 涂震宇 college of telecommunication Engineering Beijing University of Posts Telecommunication

A graph model is constructed for the Multi-user Detection of DS-CDMA system. Based on it, a Hopfield-like algorithm is put forward for the implementation of optimum receiver. Compared with the Hopfield approach, it ha... 详细信息

关键词： DS-CDMA Multi-user detection Optimum receiver Hopfield neural networks Minimum Cut (MC).

Resource allocation for D2D-assisted haptic communications

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Digital Communications and Networks 2024年第1期10卷 63-74页

作者： Yan Wu Chao Yue Yang Yang Liang Ao college of telecommunication Engineering Army Engineering University of PLANanjing210000China

Haptic communications is recognized as a promising enabler of extensive services by enabling real-time haptic control and feedback in remote environments,e.g.,teleoperation and autonomous *** the strict transmission requirements on reliability and latency,Device-to-Device(D2D)communications is introduced to assist haptic *** particular,the teleoperators with poor channel quality are assisted by auxiliaries,and each auxiliary and its corresponding teleoperator constitute a D2D ***,the haptic interaction and the scarcity of radio resources pose severe challenges to the resource allocation,especially facing the sporadic packet ***,the contentionbased access scheme is applied to achieve low-latency transmission,where the resource scheduling latency is omitted and users can directly access available *** this context,we derive the reliability index of D2D pairs under the contention-based access scheme,i.e.,closed-loop packet error ***,the reliability performance is guaranteed by bidirectional power control,which aims to minimize the sum packet error probability of all D2D *** game theory is introduced to solve the problem with low ***,a distributed power control algorithm based on synchronous log-linear learning is proposed to converge to the optimal Nash *** results demonstrate the superiority of the proposed learning algorithm.

关键词： Haptic communications D2D Power control Contention-based access Potential game

Fast multi-parameter estimation and localization for MIMO radar

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Journal of Systems Engineering and Electronics 2015年第3期26卷 486-492页

作者： Lingyun Xu Xiaofei Zhang Miao Yu college of Science Nanjing University of Aeronautics and Astronautics Nanjing telecommunication Technology Institute

This paper addresses the problem of four-dimensional angle and Doppler frequency estimation for bistatic multiple-input multiple-output （MIMO） radar with arbitrary arrays in spatial co- lored noise. A novel method for joint estimation of Doppler fre- quency, two-dimensional （2D） direction of departure and 2D direc- tion of arrival based on the propagator method （PM） for arbitrary arrays is discussed. A special matrix is constructed to eliminate the influence of spatial colored noise. The four-dimensional （4D） angle and Doppler frequency are extracted from the matrix and the three- dimensional （3D） coordinates of the targets are then calculated on the basis of these angles. The proposed algorithm provides a lower computational complexity and has a parameter estimation very close to that of the ESPRIT algorithm and the DOA-matrix al- gorithm in the high signal to noise ratio and the Cramer-Rao bound （CRB） is given. Furthermore, multi-dimensional parameters can be automatically paired by this algorithm to avoid performance degra- dation resulting from wrong pairing. Simulation results demonstrate the effectiveness of the proposed method.

关键词： four-dimensional (4D) angle estimation Doppler frequency estimation propagator method (PM) multiple-input multiple-output (MIMO) radar arbitrary array spatial colored noise.

Design of an optical receiving antenna with high gain and large field of view for indoor visible light communication

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Optoelectronics Letters 2019年第5期15卷 321-329页

作者： HAO Hong-gang DU Zhi-hua LUO Wei RUAN Wei college of Optoelectronic Engineering Chongqing University of Posts and Telecommunication

In order to meet the requirements of the high gain and wide field of view(FOV) for indoor visible light communication(VLC) system, a new optical receiving system is proposed, which integrates a Fresnel lens with a hemispherical lens. The effects of the two lenses’ spacing and the radius of the hemispherical lens on the optical gain at different FOV are investigated. As the FOV increases, the designed antenna displays enhanced reception performance compared with the traditional receiving optical antenna. The optical gain of the designed antenna is 6.88 in the condition of FOV of 40°. To further verify the rationality of the designed antenna, a model of VLC system is established based on the designed antenna in a room with a size of 5 m×5 m×3 m. The results show that the received average power using the designed antenna increases by 22.81 d Bm, and the average signal to noise ratio(SNR) is 2.3 times of that without any optical antenna. The designed antenna is promising for the application in indoor VLC systems.

关键词： field of view(FOV) visible light communication(VLC) signal to noise ratio(SNR)

On interest-rate risk management of postal savings bureau

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The Journal of China Universities of Posts and telecommunications 2007年第1期14卷 115-121页

作者： DU Chong-dong LI Su-man Finance Department Shijiazhuang Post and Telecommunication Technical College Shijiazhuang 050021 China

This article analyzes interest-rate risks faced by the postal savings bureau （PSB） based on the complete balance sheet. It presents the extended gap model and the extended duration gap model to measure the interest-rate risk, and discusses the inner balance-sheet strategies and the off-balance-sheet strategies to manage the interest-rate risks.

关键词： interest-rate risk gap model duration gap model,financial engineering PSB

Statistical properties of coherent photon-subtracted two-mode squeezed vacuum and its application in quantum teleportation

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Chinese Physics B 2014年第5期23卷 46-51页

作者：张国平郑凯敏刘世右胡利云 college of Physics and Communication Electronics Jiangxi Normal University Key Laboratory of Optoelectronic and telecommunication of Jiangxi

We introduce a kind of non-Gaussian entangled state, which can be obtained by operating a non-local coherent photon-subtraction operation on a two-mode squeezed vacuum. It is found that its normalization factor is only related to the Legendre polynomials, which is a compact expression. Its statistical properties are discussed by the negative region Wigner function with the analytical expression. As an application, the quantum teleportation for coherent states is considered by using the non-Gaussian state as an entangled channel. It is found that the teleportation fidelity can be enhanced by this non-Gaussian operation.

关键词： coherent photon subtraction two-mode squeezed vacuum quantum teleportation fidelity

Operating a geometric quantum gate by external controllable parameters

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Chinese Physics B 2010年第1期19卷 84-89页

作者：嵇英华蔡十华乐建新王资生 college of Physics and Communication Electronics Jiangxi Normal University Key Laboratory of Optoelectronic and telecommunication of Jiangxi

A scheme to perfectly preserve an initial qubit state in geometric quantum computation is proposed for a single- qubit geometric quantum gate in a nuclear magnetic resonance system. At first, by adjusting some magnetic field parameters, one can let the dynamic phase be proportional to the geometric phase. Then, by controlling the azimuthal angle in the initial state, we may realize a geometric quantum gate whose fidelity is equal to one under cyclic evolution. This means that the quantum information is no distortion in the process of geometric quantum computation.

关键词： geometric phase geometric quantum gate fidelity

Symbol Error Rate Performance Analysis of Non-Orthogonal Multiple Access for Visible Light Communications

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China Communications 2017年第12期14卷 153-161页

作者： Hongji Huang Jinyuan Wang Jie Wang Jie Yang Jian Xiong Guan Gui college of telecommunication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing China

Non-orthogonal multiple access(NOMA) is considered as one of promising radio access techniques for visible light communications(VLC) in next-generation wireless communications *** order to provide theoretical support for designing VLC-NOMA,we derive its analytic expressions for the symbol error rate(SER).Specifically,NOMA is first incorporated with appropriate VLC to establish a VLC-NOMA ***,mathematical expressions of the SER for the VLC-NOMA are ***,numerical results are provided carefully to demonstrate that the proposed VLC-NOMA scheme outperforms than state-of-the-art orthogonal frequency division multiple access(OFDMA) one in terms of SER ***,relationships between the SER performance and the number of users,power allocation coefficient and semi-angle are well investigated,which can give us a scientific guide to devise the VLC-NOMA system for achieving better SER performance.

关键词： visible light communication(VLC) non-orthogonal multiple access(NOMA) symbol error rate (SER)

Optical properties in 1D photonic crystal structure using Si/C_(60) multilayers

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Journal of Semiconductors 2009年第4期30卷 7-9页

作者：谌静唐吉玉韩培德陈俊芳 college of Physics and telecommunication Engineering South China Normal University college of Materials Science and Engineering Taiyuan University of Technology

The feasibility of using Si/C60 multilayer films as one-dimensional （1D） photonic band gap crystals was investigated by theoretical calculations using a transfer matrix method （TMM）. The response has been studied both within and out of the periodic plane of Si/C60 multilayers. It is found that Si/C60 multilayer films show incomplete photonic band gap （PBG） behavior in the visible frequency range. The fabricated Si/C60 multilayers with two pairs of 70 nm C60 and 30 nm Si layers exhibit a PBG at central wavelength of about 600 nm, and the highest re？ectivity can reach 99%. As a consequence, this photonic crystal may be important for fabricating a photonic crystal with an incomplete band gap in the visible frequency range.

关键词： fullerene Si multilayer films photonic band gap TMM method