检索结果-南通市图书馆

New Insights into Divide-and-Conquer Attacks on the Round-Reduced Keccak-MAC

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2019年第4期28卷 698-705页

作者： YE Chendong TIAN Tian National Digital Switching system Engineering and Technological research center

Keccak is the final winner of SHA-3 competition and it can be used as message authentic codes as well. The basic and balanced divide-and-conquer attacks on Keccak-MAC were proposed by Dinur et *** Eurocrypt 2015. The idea of cube attacks is used in the two attacks to divide key bits into small portions. By carefully analysing the mappings used in Keccak-MAC, it is found that some cube variables could divide key bits into smaller portions and so better divide-and-conquer attacks are obtained. In order to evaluate the resistance of Keccak-MAC against divide-and-conquer attacks based on cubes, we theoretically analyse the lower bounds of the complexities of divide-and-conquer attacks. It is shown that the lower bounds of the complexities are still not better than those of the conditional cube tester proposed by Senyang Huang et al.. This indicates that KeccakMAC can resist the divide-and-conquer attack better than the conditional cube tester. We hope that these techniques still could provide some new insights on the future cryptanalysis of Keccak.

关键词： Keccak-MAC Divide-and-conquer attacks Cube attacks

Phase Noise Effects on the Performance of High-Order Digital Modulation terahertz Communication system

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2022年第3期31卷 589-594页

作者： DENG Xianjin YANG Hao WU Qiuyu JIANG Jun LIN Changxing Institute of Electronic Engineering China Academy of Engineering Physics Microsystem and terahertz research center China Academy of Engineering Physics

As the carrier frequency goes into the terahertz band, the phase noise of the signal source has increasing impacts on the performance of the communication system. Considering a 16 QAM high-order digital modulation terahertz communication system(DMTCS),by comparing the influence of two kinds of local oscillator signal sources with different phase noise characteristics on the bit error rate(BER) performance of the system based on theoretical analysis and experimental research, it is found that the near-end phase noise of local oscillator signal source has a great influence on the BER performance of the DMTCS. The suppression of phase noise of the local oscillator signal source based on choosing loop bandwidth of the digital phase-locked loop(DPLL) at the receiving end is also discussed. It is found that the negative impacts of phase noise on BER performance of the system can be efficiently decreased by reasonably selecting the loop bandwidth of the DPLL.

关键词： DMTCS DPLL digital phase locked loops quadrature amplitude modulation 16QAM high-order digital modulation terahertz communication system digital phase-locked loop oscillators local oscillator signal source BER performance phase noise bit error rate performance signal sources near-end phase noise effects error statistics

A 220 GHz Orthogonal Modulator Based on Subharmonic Mixers Using Anti-Paralleled Schottky Diodes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2022年第3期31卷 562-568页

作者： HE Yue LIU Ge LIU Juan LIN Changxing SU Wei Microsystem and terahertz research center China Academy of Engineering Physics Institute of Electronic Engineering China Academy of Engineering Physics

In this paper, A 220 GHz orthogonal modulator based on two symmetrical subharmonic mixers is designed, analyzed and measured, where the mixers are implemented basde on antiparallel Schottky *** orthogonal modulator consists of a 90° phase shifted220 GHz 3 d B coupler, two sub-harmonically pumped mixers and an in-phase 110 GHz 3 d B power divider. The IF output signals are in-phase(I) branch and quadrature(Q) branch operating from DC±3.5 GHz. In the back to back experimentaltests, it is shown that the conversion loss of the two 220 GHz I/Q mixers is less than 30 d B when the IF operating frequency is DC-3.5 GHz, IF input power is-10 d Bm and the LO power is around 6 m W. Based on floating-point simulation, the amplitude and phase imbalance of the I/Q mixer are less than 0.2 d B and 2 degree respectively. When the 220 GHz modulator and demodulator are set in a back to back configuration, a signal-to-noise ratio of 21 d B can be obtained using the 16 QAM modulation type.

关键词： subharmonic mixers amplitude imbalance I-Q mixer floating-point simulation power dividers millimetre wave mixers millimetre wave diodes waveguide couplers quadrature amplitude modulation Schottky diode mixers radio-over-fibre phase imbalance orthogonal modulator power divider 16 QAM modulation subharmonically pumped mixers quadrature branch in-phase branch antiparalleled Schottky diodes waveguide coupler

A Software Defined Open Wi-Fi Platform

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2017年第7期14卷 137-151页

作者： Kai Kang Zhenghang Zhu Dehua Liu Wuxiong Zhang Hua Qian Shanghai Advanced research Institute Chinese Academy of Sciences Shanghai research center for wireless Communications

wireless local area network(WLAN) is an indivisible part of the next generation wireless system. In this paper, an open Wi-Fi platform is designed and developed with special consideration of real-time signal processing. Such system can help accelerate research and development of future wireless network, especially in the case of cellular/Wi-Fi co-existing networks. This platform is based on the Intel general-purpose processor and the universal software radio peripheral(USRP) radio front end. The design including the physical layer implementations is purely software and is optimized for real-time signal processing on the general purpose processor. In the lab experiment, this platform supports baseband rate up to 700 Mbps with 2 transmitters in 80 MHz bandwidth. A cellular-Wi-Fi signaling interface between the Wi-Fi access point(AP) and the 5G core network is also developed and validated as an example for wireless resource allocation.

关键词： Wi-Fi IEEE 802.11 5G network convergence software defined radio (SDR)

维普期刊数据库

Cache Power Optimization Based on Compare-Based Adaptive Clock Gating and Its 65nm SoC Implementation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2017年第1期26卷 128-131页

作者： LI Jie WAN Xing WU Jianbing SHAN Weiwei National ASIC system Engineering research center Southeast University

In most embedded microprocessor based system on chips(So Cs), cache has become a ma jor source of power consumption due to its increasing size and high access rate. Power optimization of cache based on Compare-based adaptive clock gating(CACG) is proposed to reduce the power waste due to cache idle. By detecting the cache's working state, the CACG can automatically turn off its clock when it is in idle state, saving a large percentage of dynamic power. Measurements of a real So C chip fabricated under TSMC 65 nm CMOS process show that an average of 30.3% power reduction is gained in Dhrystone test benchmark at a cost of negligible area overhead and no virtually performance loss.

关键词： Self-adaptive clock gating Embedded processor Cache idle Low power

Low Overhead and Fast Reaction Adaptive Clocking system for Voltage Droop Tolerance

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2019年第3期28卷 503-507页

作者： SHANG Xinchao SHAN Weiwei XIANG Yiming WAN Liang FAN Ao National ASIC system Engineering research center Southeast University

Variation in on-chip power supply continues to be a major challenge to limit circuit performance. To mitigate the impact of high-frequency voltage droop, a novel all-digital adaptive clock system is proposed. The adaptive clock system is composed of a droop detector and an adaptive clock generator, which directly stretch the clock period when the circuit suffers from the supply voltage droop. The droop detector circuit detects the VDD droop and the digital adaptive clock generator circuit selects the stretched clock to prevent timing-margin failures. The response time for droop detection and clock stretch can be as fast as one cycle. The whole scheme is used on a test circuit under SMIC 40 nm CMOS process with a layout area of 900 um*1100 um. Postlayout simulation results demonstrate power reductions are 7% at 1.1 V and 15% at 0.7 V for a 10% VDD droop,respectively.

关键词： Voltage droop Adaptive clock system Droop detector Adaptive clock generator

Independent control of harmonic amplitudes and phases via a time-domain digital coding metasurface

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2018年第1期7卷 201-210页

作者： Jun Yan Dai Jie Zhao Qiang Cheng Tie Jun Cui State Key Laboratory of millimeter waves Southeast University210096 NanjingChina Synergetic Innovation center of wireless Communication Technology Southeast University210096 NanjingChina

Harmonic manipulations are important for applications such as wireless communications,radar detection and biological monitoring.A general approach to tailor the harmonics involves the use of additional amplifiers and phase shifters for the precise control of harmonic amplitudes and phases after the mixing process;however,this approach leads to issues of high cost and system *** composed of a periodic array of subwavelength resonators provide additional degrees of freedom to realize customized responses to incident light and highlight the possibility for nonlinear control by taking advantage of time-domain ***,we designed and experimentally characterized a reflective time-domain digital coding metasurface,with independent control of the harmonic amplitude and *** the reflection coefficient is dynamically modulated in a predefined way,a large conversion rate is observed from the carrier signal to the harmonic components,with magnitudes and phases that can be accurately and separately *** addition,by encoding the reflection phases of the meta-atoms,beam scanning for multiple harmonics can be implemented via different digital coding sequences,thus removing the need for intricate phase-shift *** work paves the way for efficient harmonic control for applications in communications,radar,and related areas.

关键词： harmonic harmonics surface

A Reconfigurable Hardware Architecture for Packet Processing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2018年第2期27卷 428-432页

作者： DUAN Tong LAN Julong HU Yuxiang LIU Shiran National Digital Switching system & Engineering Technological research center

In this paper, we propose a reconfigurable packet processing hardware architecture for future switch,in which several protocol-independent action units are introduced to remove the protocol dependence of conventional packet processors. With the proposed architecture,any specified header fields can be mapped into the right action unit, so that the processor can meet any packet processing demands. To reduce the hardware resource cost,the processor cost model and optimization algorithm are proposed. The Net FPGA-based implementation shows a throughput of 94 Gb/s with 64-B packets. The programmability cost is approximately 1.5 times of conventional design, which consumes only 8% of the total FPGA resources.

关键词： Packet processing Hardware architecture Reconfigurable Protocol-independent

research on Dielectric Focusing Lens Antenna for HPM Atmospheric Breakdown Experiments

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of electronics 2019年第1期28卷 202-206页

作者： YU Daojie CHAI Mengjuan ZHOU Dongfang ZHOU Changlin WEI Jinjin HU Junjie CAI Beibing ZHAO Tongcheng National Digital Switching system Engineering and Technological research center

To distinguish the dielectric surface breakdown from the atmospheric breakdown, one method for atmospheric breakdown experiment by loading dielectric focusing lens is proposed. The focusing characteristics of dielectric focusing lens are investigated for the microwave frequency on the order of 1.3GHz to 9.3GHz, the lens focal length on the order of 0.3m to 0.9m and the dielectric constant on the order of 0.3 to 0.9. Simulations show that higher frequency, shorter focal length, and fitter dielectric constant result in better focus effect that the rising and falling edges of electric field strength change faster near the focus which is closer to the theoretical value. A dielectric focusing lens for the S-band is optimally designed with the polytetrafluoroethylene of 0.32 m thickness, 0.6m diameter,and 0.4m focal length. The focus indicator of dielectric lens is measured and the atmospheric breakdown experiment is carried out. The experimental values of atmospheric breakdown are consistent with the theoretical values. The electric field strength with the lens at the focus is 5–6times greater than that without focusing lens. The image of atmospheric breakdown by the dielectric lens focusing method experiment is clearer than that by the direct radiation method.

关键词： HPM Atmospheric breakdown experiment Dielectric focusing lens antenna Near field Focusing effect