检索结果-内蒙古大学图书馆

15th International Conference on Optical Technologies for Telecommunications

作者： Gabdulkhakov, Ildaris M. Morozov, Oleg G. Morozov, Gennady A. Zastela, Mikhail Yu. Tyajelova, Alina A. Sarvarova, Lucia M. PJSC Tattelecom 57 N Ershov St Kazan 420061 Russia Kazan Natl Res Tech Univ 10 K Marx St Kazan 420111 Russia

ISBN: (数字)9781510621206

ISBN: (纸本)9781510621206;9781510621190

The technology of frequency coding in channels of quantum key distribution allows to determine the ground state of photons through the value of the amplitude of its carrier, frequency modulated in phase (PM) or amplitude (AM) by a radio- frequency signal, and the resulting side components. Over the past twenty years, it has been substantially modified and improved. At the same time, in recent works, an expanded understanding of the frequency coding principle is used, in which each photon state is associated not with the phase of the modulating signal at a certain frequency, but with one or more sideband frequencies or the carrier frequency of the photon itself. In this paper, we present the results of constructing a frequency coding system of quantum key distribution (QKD) based on the serial electro- optical photon amplitude modulation and phase commutation. The possibility of reducing the probability of achieving a positive result in PNS attacks by Eva is shown by eliminating the carrier of the signal transmitted via the quantum channel from the structure of the key distribution. It was early noted, that the smallest value of QBER is achieved in schemes with a passive definition of one or two basic states of a photon, i.e. without the use of remodulation processes, that is realized in considering. Additionally it is not necessary to form a notch filter system, which is usually carried out using fiber Bragg gratings (FBG) or arrayed waveguide gratings (AWG) for discrimination the photon carrier and its sideband components.

关键词： quantum cryptography quantum key distribution frequency coding electro-optical photon amplitude modulation electro-optical photon phase commutation PNS attack remodulation process notch filter

来源：评论

学校读者我要写书评

暂无评论

Range Ambiguous Clutter Suppression for Forward-Looking Airborne Radar Based on frequency coding and Phase Waveforms Modulation in Slow-Time

引用

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2024年第6期60卷 8470-8482页

作者： Qiu, Zizhou Duan, Keqing Liao, Zhipeng Sun Yat Sen Univ Sch Elect & Commun Engn Shenzhen 518107 Peoples R China

Airborne radars tasked with detecting low-altitude or ground targets frequently face the challenge posed by ground and sea clutter interference, which can drastically reduce target detection capabilities. To counteract this, airborne radars are necessitated to implement clutter suppression strategies, among which space-time adaptive processing (STAP) stands out as a key technique. Nevertheless, in forward-looking mode, the Doppler frequency of clutter varies with distance due to range dependency. Furthermore, operational modes with medium-to-high pulse-repetition frequencies introduce range ambiguity into radar signals. The combination of clutter range dependency and range ambiguity severely diminishes the clutter suppression efficacy of STAP. In response to these challenges, this article proposes a strategy for suppressing range ambiguous clutter, using slow-time frequency coding and phase waveforms modulation radar. This approach involves utilizing distinct phase waveforms and carrier frequency modulations for different pulses at the transmitter. At the receiver, the method employs joint filtering within the Doppler and waveform domains, exploiting the unique characteristics of the transmitted signal to resolve range ambiguity. In addition, Doppler compensation is deployed to address the issue of clutter range dependency. Ultimately, STAP is utilized to process clutter from each range region individually, thus achieving efficient suppression of range ambiguity clutter. Theoretical analysis and simulation experiments are included, demonstrating the efficacy of the proposed method.

关键词： Clutter Radar Airborne radar Radar clutter Doppler effect Encoding Radar detection frequency coding phase waveform modulation range ambiguous clutter space-time adaptive processing (STAP)

来源：评论

学校读者我要写书评

暂无评论

Two-step quantum secure direct communication scheme with frequency coding

引用

Chinese Physics B 2017年第3期26卷 231-235页

作者：赵学亮李俊林牛鹏皓马鸿洋阮东 Department of Physics Tsinghua University School of Science Qingdao University of Technology

Quantum secure direct communication （QSDC） is an important branch of quantum cryptography. It can transmit secret information directly without establishing a key first, unlike quantum key distribution which requires this precursory event. Here we propose a QSDC scheme by applying the frequency coding technique to the two-step QSDC protocol, which enables the two-step QSDC protocol to work in a noisy environment. We have numerically simulated the performance of the protocol in a noisy channel, and the results show that the scheme is indeed robust against channel noise and loss. We also give an estimate of the channel noise upper bound.

关键词： quantum cryptography quantum secure direct communication frequency coding

来源：评论

学校读者我要写书评

暂无评论

Orthogonal frequency coding for SAW tagging and sensors

引用

IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND frequency CONTROL 2006年第2期53卷 377-384页

作者： Puccio, D Malocha, DC Saldanha, N Gallagher, DR Hines, JH Univ Cent Florida Elect & Comp Engn Dept Orlando FL 32816 USA Microsensor Syst Inc Bowling Green KY USA

Surface acoustic wave (SAW)-based sensors can offer wireless, passive operation in numerous environments, and various device embodiments are used for retrieval of the sensed data information. Single sensor systems typically can use a single carrier frequency and a simple device embodiment because tagging is not required. In a multisensor environment, it is necessary to both identify the sensor and retrieve the sensed information. This paper presents the concept of orthogonal frequency coding (OFC) for applications to SAW sensor technology. The OFC offers all advantages inherent to spread spectrum communications, including enhanced processing gain and lower interrogation power spectral density (PSD). It is shown that the time ambiguity in the OFC compressed pulse is significantly reduced as compared with a single frequency tag having the same code length, and additional coding can be added using a pseudo-noise (PN) sequence. The OFC approach is general and should be applicable to many differing SAW sensors for temperature, pressure, liquid, gases, etc. Device embodiments are shown, and a potential transceiver is described. Measured device results are presented and compared with coupling of modes (COM) model predictions to demonstrate performance. Devices then are used in computer simulations of the proposed transceiver design, and the results of an OFC sensor system are discussed.

关键词： pseudonoise codes sensor fusion spread spectrum communication surface acoustic waves SAW tagging coupling of modes model multisensor environment orthogonal frequency coding power spectral density pseudo-noise sequence spread spectrum communications surfa Spread spectrum communication frequency coding Power spectral density OFC1 gene surface acoustic wave sensors Sensors Surface acoustic waves Sensor fusion pseudonoise codes Sensor systems

来源：评论

学校读者我要写书评

暂无评论

CURRENT SOURCE DENSITY ANALYSIS OF frequency coding IN THE INFERIOR COLLICULUS

引用

HEARING RESEARCH 1987年第2-3期25卷 257-266页

作者： HARRIS, DM Dept. of Otolaryngology-Head and Neck Surgery Eye & Ear Infirmary University of Illinois College of Medicine at Chicago 1855 West Taylor Street Chicago IL 60612 U.S.A.

Current source density (CSD) analysis is a technique that provides information about the time course and spatial location of transmembrane currents derived from a laminar collection of evoked potentials. Restrictive conditions for aquisition of evoked potentials are required in order to yield a one-dimensional CSD analysis that is an accurate estimate of synaptic activity. Satisfaction of these conditions was assumed in recordings of tone-burst-evoked potentials along the axis of symmetry (tonotopic) in the inferior colliculus of adult mongolian gerbils. Off-line these data were converted into distance/voltage functions. The second spatial derivatives of these functions gave a family of profiles of the spatial distribution of current source and sink densities at discrete latencies relative to the stimulus. Results indicate a frequency-dependent spatial shift in the evoked current sink of about 280 .mu.m octave. This sink, indicative of local excitatory synaptic drive, is surrounded, both spatially and temporally, by current sources. The spatial extent of excitation as estimated from CSD analysis, compares well quantitatively with predictions from an across-neuron model that is based on single unit data.

关键词： current source density frequency coding inferior colliculus neuronal ensemble

来源：评论

学校读者我要写书评

暂无评论

Molecular mechanisms of short-term plasticity as a basis of frequency coding: The role of proteolytic systems

引用

NEUROCHEMICAL JOURNAL 2014年第1期8卷 1-10页

作者： Kudryashova, I. V. Russian Acad Sci Inst Higher Nervous Act & Neurophysiol Moscow Russia

During vital activities, synapses permanently receive afferent inflow followed by short-term modifications of transmission. These modifications play an important role in information processing, creating the basis for the formation of the temporal pattern of a response and frequency coding. A neuronal network with these properties may not only differentiate frequency features of input signals but can also form individual patterns of activity in each of the outputs. Here, we review the data on the dependence of the parameters of short-term plasticity on the molecular composition of synaptic compartments. The role of regulated proteolysis in the formation of a specific molecular composition in the pre- and postsynapses is discussed. The specific pattern of enzyme activation in each compartment coordinates proteolytic activity in accordance with input signals. We believe that the molecular composition in each synapse may depend on previous experience and represent the substrate of memory, which determines recall, not only the spatial pattern, but also the frequency-temporal pattern, which is required for adaptive behavior.

关键词： frequency coding learning and memory paired-pulse facilitation paired-pulse depression molecular mechanisms of short-term plasticity proteolysis

来源：评论

学校读者我要写书评

暂无评论

Quantum secure direct communication with frequency coding scheme 4

Quantum secure direct communication with frequency coding sc...

引用

Conference on Quantum and Nonlinear Optics IV

作者： Zhao, Xue-Liang Ruan, Dong Tsinghua Univ Dept Phys Beijing Peoples R China

ISBN: (数字)9781510604780

ISBN: (纸本)9781510604773;9781510604780

Quantum secure direct communication (QSDC) is an important branch of quantum cryptography. It can transmit secret information directly without establishing a key first, unlike quantum key distribution which requires this precursive event. One of the most highlighted QSDC protocol is the Two-step protocol. This paper will focus on proposing a frequency coding scheme in the Two-step protocol, while retaining other contents of the QSDC protocol. This new coding scheme will significantly increase the protocol's ability against channel noise and loss, and provides an efficient protocol for secure direct quantum communication in a noisy environment. Besides, the frequency coding technology is also easy to understand and highly practical. After numerically simulating the performance of the protocol in a noisy channel, the results showed that the scheme was robust against channel noise and loss.

关键词： Quantum cryptography QSDC Noise channel frequency coding

来源：评论

学校读者我要写书评

暂无评论

A frequency coding applied for fingerprint classification

A frequency coding applied for fingerprint classification

引用

3rd International Conference on Experimental Mechanics

作者： Bao, NK Li, BY City Univ Hong Kong Optoelect Res Ctr Dept Elect Engn Kowloon Hong Kong Peoples R China

In this paper, a novel approach for fingerprint identification has been proposed in which a frequency coding can be performed for fingerprint classification. The feature of orientation is extracted by spectrum analysi... 详细信息

ISBN: (纸本)0819442615

关键词： digital FFT frequency coding code-vector

来源：评论

学校读者我要写书评

暂无评论

STUDY ON frequency coding ANTI-INTERFERENCE SYSTEM FOR DATA TRANSMISSION IN SHALLOW WATER ACOUSTIC CHANNELS

引用

Chinese Journal of Oceanology and Limnology 2002年第4期20卷 309-315页

作者：许肖梅粘宝卿刘志鑫许鹭芬黄衍镇 Institute of subtropical Oceanography Xiamen University 361005 Xiamen China

Achieving reliable underwater communication in shallow water acoustic channels is a difficult task because of the random time varying nature of multipath propagation, severe amplitude fluctuation, and spatial variability of the channel conditions. This paper describes a new signal processing technique frequency coding and decoding by means of real time measurement of signal width, jamming and suppressing multipath interference and using redundant coder. The application of the technique to the model ZTY 1 status monitor for underwater system of seabed is introduced in this paper. The main principle, the technique specifications and the key techniques of the system are discussed here. Theoretical estimations and experimental results proved that the performance of the system is excellent. The method can be used for some other related low data rate data transmission detecting in shallow water acoustic channel.

关键词： acoustic channels frequency coding anti interference

来源：评论

学校读者我要写书评

暂无评论

Intra-Pulse frequency coding Design for a High-Resolution Radar against Smart Noise Jamming

引用

REMOTE SENSING 2022年第20期14卷 5149-5149页

作者： Xi, Rongyan Ma, Dingyou Liu, Xiang Wang, Lei Liu, Yimin Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China Beijing Univ Posts & Telecommun Sch Informat & Commun Engn Key Lab Universal Wireless Commun Minist Educ Beijing 100876 Peoples R China China Acad Engn Phys Inst Elect Engn Mianyang 621900 Sichuan Peoples R China

Smart noise jamming forms active jamming by intercepting, modulating, and forwarding radar signals into the radar receiver, which seriously affects the radar range recovery performance. In this paper, we propose a novel waveform design approach and an efficient range recovery method for high-resolution radar in the jamming scenario. Firstly, we propose an intra-pulse frequency-coded frequency-modulated continuous waveform (IPFC-FMCW), which contains multiple FMCW chips with different widths and frequencies, to combat the smart noise jamming. After the jamming suppression, the proposed waveform has a low sidelobe level, which is different from traditional FMCW signals for which the observations are periodically missing, resulting in high sidelobe levels. Then, to improve the range recovery performance of the waveform after jamming suppression, we optimize the range profile by designing the transmit waveform and then solve it by a simulated annealing algorithm. Next, based on the designed waveform, we derive the echo model after jamming suppression and propose a gridless compressed sensing (CS) method to recover the range of the targets. Compared with the existing waveforms and methods, the proposed waveform and the processing method achieve better range recovery performance in the jamming scenario. Numerical simulations are utilized to demonstrate the range recovery effectiveness of the proposed waveform and method in smart noise jamming.

关键词： high-resolution radar frequency coding smart noise jamming waveform design

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：