ANALYSIS OF THE TRANSMISSION PROPERTIES OF TAPERED MUTLICONDUCTOR INTERCONNECTING BUSES IN HIGH-SPEED INTEGRATED CIRCUITS

Analysis approach and formulas for the transmission properties of uniform multicon-ductor interconnecting buses in high-speed integrated circuits are presented in this article. And further, by using a network approach, a tapered bus system can be analyzed as a set of cascaded uniform buses with slightly different strip widths. Obtained results are in good agreement with the experimental data.

Development of 16-channels Compact EEG System Using Real-time High-speed Wireless Transmission

For the convenience of people with disability and for normal people, a demand for intelligent interfaces is ever increasing and therefore related studies are actively being conducted. Recently a study is being conducted to develop an interface through face expression, movement of the body and eye movements, and further more active attempts to use electrical signals(brainwave, electrocardiogram, electromyogram) measured from the human body is also actively being progressed. In addition, the development and the usage of mobile devices and smart devices are promoting these research activities even more. The brainwave is measured by electrical activities between nerve cells in the cerebral cortex using scalp electrodes. The brainwave is mainly used for diagnosis and treatment of diseases such as epilepsy, encephalitis, brain tumors and brain damage. As a result, the brainwave measurement methods and analytical methods were developed. Interface using the brainwave will not go through language or body behavior which is the result of the information processed by the brain but will pass directly to the system providing a brain-computer interface (BCI). This is possible because a variety of the brainwave appears depending on the human’s physical and mental state. Using the brainwave with the intelligent brain-computer interface or combining it with mobile devices and smart devices, regardless of space constraints, the brainwave measurement should be possible.[4,7] In this study, in order to measure the brainwave without spatial constraint, 16 channel compact brainwave measurements system using a high-speed wireless communications were designed. It was designed with a 16 channel to classify the various brainwave patterns that appear and for estimating the location of the nerve cells that triggered the brainwave. And in order to transmit the brainwave data within the channel without loss, a high-speed wireless communication must be possible that can enable a high-speed wireless transmission more sufficient than the Bluetooth, therefore, 802.11 compliant Wi-Fi communication methods were used to transfer the data to the PC. In addition, by using an analog front-end IC having a single-chip configuration with real-time digital filters, the miniaturization of the system was implemented and in order to verify the system Eye-blocking was used to observe the changes in the EEG signal.

Analysis of vibration and frequency transmission of high speed EMU with flexible model

When the operation speed of the high-speed train increases and the weight of the carbody becomes lighter,not only does the sensitivity of the wheel/rail contact get higher,but also the vibration frequency range of the vehicle system gets enlarged and more frequencies are transmitted from the wheelset to the carbody.It is important to investigate the vibration characteristics and the dynamic frequency transmission from the wheel/rail interface to the carbody of the high-speed electric multi-uint（EMU）.An elastic highspeed vehicle dynamics model is established in which the carbody,bogieframes,and wheelsets are all dealt with as flexible body.A rigid high-speed vehicle dynamics model is set up to compare with the simulation results of the elastic model.In the rigid vehicle model,the carbody,bogieframes and wheelsets are treated as rigid component while the suspension and structure parameters are the same as used in the elastic model.The dynamic characteristic of the elastic high speed vehicle is investigated in time and frequency domains and the di ff erence of the acceleration,frequency distribution and transmission of the two types of models are presented.The results show that the spectrum power density of the vehicle decreases from the wheelset to the carbody and the acceleration transmission ratio is approximately from 1%to 10%for each suspension system.The frequency of the wheelset rotation is evident in the vibration of the flexible model and is transmitted from the wheelset to the bogieframe and to thecarbody.The results of the flexible model are more reasonable than that of the rigid model.A field test data of the high speed train are presented to verify the simulation results.It shows that the simulation results are coincident with the field test data.

Theoretical Study on Non-transmission High Efficient Parallel Camber Grinding Machine

Be directed against the development trend of modern CNC grinding machine towards high precision and high efficiency, some general weaknesses of existing camber grinding machine are analyzed in detail. In order to develop new type CNC camber grinding machine that can grind complex die, and genuinely achieved accurate feed and high efficient grinding, a new type camber grinding machine is put forward, called non-transmission virtual-shaft CNC camber grinding machine. Its feed system is a parallel mechanism that is directly driven by linear step motor. Therefore, traditional transmission types, such as the ball lead-screw mechanisms, the gears, the hydraulic transmission system, etc. are cancelled, and the feed system of new type CNC camber grinding machine can truly possess non-creep, good accuracy retentiveness a wide range of feed-speed change, high kinematical accuracy and positioning precision, etc. In order to realize that the cutting motion is provided with high grinding speed, step-less speed variation, high rotational accuracy, good dynamic performance, and non-transmission, the driving technology of hollow rotor motor is applied to drive the spindle of new type grinding machine,thus leading to the elimination of the transmission parts of cutting motion. The principle structure model of new type camber grinding machine is advanced. The selection, control gist and driving circuit line of the linear step motor are expounded. The main technology characteristics and application advantages of non-transmission virtual-shaft CNC camber grinding machine are introduced.

基于GSM-R的高铁无线通信系统性能分析与优化

目前,国内高速铁路使用基于全球铁路移动通信系统(Global System for Mobile Communications-Railway,GSM-R)的双向无线通信系统,实现列车与地面之间的安全信息传输。然而,无线通信存在传输延迟和丢包,严重时会影响运行效率,因此需要研究GSM-R系统服务质量(Quality of Service,QoS)参数,以满足实时性和可用性需求。选取传输延时作为待优化的GSM-R无线通信系统QoS参数,定量分析端到端传输延迟时间,提出基于无线传输参数自适应的加强学习优化方案。仿真结果表明,该方法可以显著提升无线通信系统性能。

基于IR-UWB的高吞吐量、低延时MAC协议硬件设计

针对IEEE 802.15.4高速数据传输的应用场景,提出一种具有高吞吐量和低延时特性的定制化MAC协议。基于HRP UWB PHY对数据传输模型和吞吐量深入分析,并结合MAC协议的冲突避免载波侦听多路访问(Carrier Sense Multiple Access with Collision Avoid,CSMA-CA)和保障时隙(Guaranteed Timeslot,GTS)实时传输的特性,设计了该机制有效的管理流程。最后在Vivado中使用Verilog HDL对MAC控制器进行硬件设计和验证。仿真结果表明,与经典IEEE 802.15.4 MAC协议相比,该MAC控制器的吞吐量提高了26%,同时数据传输时延降低了17%。

30 Tbit/s DP-16QAM传输系统中基于机器学习的非线性均衡方法

【目的】采用机器学习的方法对30 Tbit/s(60×500 Gbit/s)奈奎斯特双偏振—16进制正交幅度调制(DP-16QAM)在G.654E光纤中传输6300 km传输系统的传输结果进行非线性均衡,降低传输误码率(BER)。【方法】借鉴卷积神经网络的“感受野”机制,设计“卷积核”大小,根据划分采样数据构造数据集。选取并调试合适的参数构造人工神经网络。采集在C波段的不同波长、不同光信噪比和不同入纤功率发送和接收一一对应的数据,参照经典全连接神经网络结构,根据数据集数据结构来构建神经网络,并对实部和虚部分别进行网络拟合,训练完成后将测试数据集送入网络,在这3个方面分别进行计算并与传统方法进行比对。【结果】文章采用两种神经网络拟合了C波段频率在191.5625~195.9875 THz 60个不同波长传输条件下的传输BER,在与最大似然序列估计(MLSE)算法的对比中,网络1和网络2 BER分别平均降低了23%和41%。在数据中选择了频率为193.8125 THz的光进行入纤功率范围为14~19 dBm的计算,网络1和网络2 BER分别平均降低了32%和52%。在不同光信噪比下,网络1和网络2 BER分别平均降低了30%和57%。【结论】引入的两种神经网络在相干传输系统的非线性均衡中都有不俗的表现。同时,网络层数和节点数会共同影响拟合结果,一般说来,增加层数和节点数可以获取更好的拟合效果,但与之对应的便是模型参数的增多、占用空间的增大和训练时间的增长,所以在应用中应考虑实际情况,在拟合效果和模型属性中进行取舍。

Sensitivity analysis of distributed parameter elements in high-speed circuit networks

This paper presents an analysis method, based on MacCormack＇s technique, for the evaluation of the time domain sensitivity of distributed parameter elements in high-speed circuit networks. Sensitivities can be calculated from electrical and physical parameters of the distributed parameter elements. The proposed method is a direct numerical method of time-space discretization and does not require complicated mathematical deductive process. Therefore, it is very convenient to program this method. It can be applied to sensitivity analysis of general transmission lines in linear or nonlinear circuit networks. The proposed method is second-order-accurate. Numerical experiment is presented to demonstrate its accuracy and efficiency.

FC-AE-1553光纤总线技术在运载火箭测量系统的应用

运载火箭测量系统使用LVDS、RS422、1553B等总线接口,以混合应用方式构成了测量系统数据传输网络。随着运载火箭测量系统技术发展,高带宽传输、设备数据共享、电缆网轻质化等需求日益增长,测量系统亟需发展新型总线技术满足应用需求。FC-AE-1553光纤总线技术具有时间同步、高速传输、多冗余和多级网络级联等总线网络特点,能够应用于航空航天和船舶等高速高可靠应用领域。运载火箭测量系统采用FC-AE-1553光纤总线技术,在保证测量系统高可靠通信的同时,能够极大提升测量系统数据传输通信速率,实现测量系统高速信息传输。

无砟轨道减振垫层刚度-阻尼匹配设计分析

随着高速铁路路网的不断加密,线路不可避免穿越环境敏感区,由列车运行所引起的振动问题日益严重。目前常采用减振垫层进行振动控制,但其参数取值大多从单一角度考虑,缺乏协调设计,导致减振效果不佳。为探究减振垫层刚度与阻尼合理匹配设计值,在有限元中建立车辆-减振轨道-下部结构耦合模型,利用显示动力学分析不同减振垫参数组合值下轨道结构动力响应,通过规范限值剔除极端工况,利用加速度振级、传递损失、插入损失对不同参数组合值下的减振性能进行全方位、多角度分析。结论如下:(1)轨道各结构动力响应满足规范限值要求时,减振垫层刚度应不小于60 MPa/m,阻尼不小于0.1 MN·s/m^(3);(2)减振效果总体上与刚度呈负相关趋势,在减振垫层刚度-阻尼组合值分别为60 MPa/m、0.1 MN·s/m^(3)与100 MPa/m、0.1 MN·s/m^(3)时,底座板动力响应较小;(3)从传递损失角度出发,减振垫层可有效削弱轨道中、高频段振动能量,从插入损失角度出发,虽然垫层会放大某些低频振动,但对中、高频段减振效果较好,对比后取减振垫层刚度-阻尼组合值为100 MPa/m、0.1 MN·s/m^(3)。研究结果表明,对减振垫参数进行协调设计可最大发挥其减振性能。

50 GHz Spaced 4 ×40 Gbit/s WDM Transmission over 700 km Using 6 ps Bandlimited RZ Signals

In this paper, we present 50 GHz spaced 4 ×40 Gbit/s WDM transmission over 700 km using SMF-based Effective Area Enlarged Positive Dispersion Fiber in a recirculating loop. The paper uses bandlimited RZ signals and shows that transmission distance of 700 km can be achieved with BER ≤ 10-9 using 6 ps pulsewidth for each data signal. To attain this, optical filters with sharp transmission characteristics are used in both transmitter and receiver. The results demonstrated in this paper are based on simulation, and the author believes the propagation distance reached in the paper is the longest distance achieved for such system.

Design of data transmission for a portable DAQ system

Field Programmable Gate Array(FPGA),combined with ARM(Advanced RISC Machines) is increasingly employed in the portable data acquisition(DAQ) system for nuclear experiments to reduce the system volume and achieve powerful and multifunctional capacity.High-speed data transmission between FPGA and ARM is one of the most challenging issues for system implementation.In this paper,we propose a method to realize the high-speed data transmission by using the FPGA to acquire massive data from FEE(Front-end electronics) and send it to the ARM whilst the ARM to transmit the data to the remote computer through the TCP/IP protocol for later process.This paper mainly introduces the interface design of the high-speed transmission method between the FPGA and the ARM,the transmission logic of the FPGA,and the program design of the ARM.The theoretical research shows that the maximal transmission speed between the FPGA and the ARM through this way can reach 50 MB/s.In a realistic nuclear physics experiment,this portable DAQ system achieved 2.2 MB/s data acquisition speed.

Boundary Induced Inductive Delay in Transmission of Electromagnetic Signals

When an electromagnetic signal transmits through a coaxial cable, it propagates at speed determined by the dielectrics of insulator between the cooper core wire and the metallic shield. However, we demonstrate here that, once the shielding layer of the coaxial cable is cut into two parts leaving a small gap, while the copper core wire is still perfectly connected, a remarkable transmission delay immediately appears in the system. We have revealed by both computational simulation and experiments that, when the gap spacing between two parts of the shielding layer is small, this delay is mostly determined by the overall geometrical parameters of the conductive boundary which connects two parts of the cut shielding layer. A reduced analytic formula for the transmission delay related with geometrical parameters, which is based on an inductive model of the transmission system, matches well with the fitted formula of the simulated delay. This above structure is analog to the situation that an interconnect is between two inter-modules in a circuit. The results suggest that for high speed circuits and systems, parasitic inductance should be taken into full consideration, and compact conductive packaging is favorable for reducing transmission delay of inter-modules, therefore enhancing the performance of the system.

PLC控制的造纸机传动系统设计研究

高速造纸机是造纸业的重要设备之一,其传动系统的设计在工业自动化中具有一定的挑战性。PLC控制系统为这一领域的发展带来了无限的潜力。结合造纸机结构以及工作原理,分析高速造纸机传动系统设计需求,从整体结构、硬件结构等多方面介绍传动系统的设计思路,以期为造纸工业的自动化以及智能化发展提供参考。

一种轻小型遥感相机多通道高速图像传输方案

遥感相机图像传输接口性能是影响相机整体性能的重要指标,为解决多通道相机图像数据传输速率高且同时满足轻小型化需求的问题,文章提出一种高吞吐率、低误码率的轻小型相机多通道高速图像数据传输方案,该方案基于CoaXPress接口采用Aurora 8B/10B通信协议,通过FPGA吉比特发送器(Gigabit Transceiver,GTX)实现4套焦面组件下行的高速图像传输,测试数据率达到13 Gbit/s,同时实现上行21 Mbit/s的相机控制数据率。仿真及测试结果表明:该方案极大地提高了相机的图像数据传输速率,接口电缆数量较传统减少近50%,可满足轻小型遥感相机多通道高速图像传输需求,为各类遥感相机高速小型化提供新的解决方案。

《空间数据与信息传输系统 航天器SpaceFibre总线通信协议》国家标准解读

SpaceFibre总线是专门面向新一代智能航天器在轨海量数据可靠传输设计的新型超高速组网互联技术,其提供了优先级、带宽预留和时隙规划等多种服务质量保证机制,支持最高50Gbps的超高链路传输带宽,具备数据检错重传、链路状态机管理、多信道冗余与平滑降级等多层级容错机制,在航天器安全关键应用领域具有显著优势。制定GB/T 43670—2024《空间数据与信息传输系统SpaceFibre总线通信协议标准》,对于支持SpaceFibre核心芯片和网络系统研制,保证各类星载高性能处理设备之间高速通信接口一致性和匹配性,实现整星系统快速集成测试和不同航天器之间产品可重用性具有极其重要的意义。

高速列车齿轮传动系统机电耦合建模与振动特性分析

为研究高速列车运行过程中齿轮传动系统的振动特性,文章基于多体系动力学理论和交流电传动理论,利用Simpack和Simulink建立了高速列车齿轮传动系统机电耦合动力学模型,并开展了有、无轮轨激励下的振动特性分析,通过对比仿真与实测齿轮传动系统振动加速度时频域数据,验证了模型的准确性。对比有、无轮轨激励工况显示:无轮轨激励时振动幅值较小,在频域上以内部齿轮啮合激励频率为主;而在轮轨激励作用下随着运行速度增加,齿轮传动系统振幅急剧增大,在频域上低速段以齿轮啮频为主,高速段以车轮多边形为主。分相区内外对比显示:电机扭矩作用使齿轮传动系统振动幅值显著增大,且频域中齿轮啮频和车轮多边形主频成分更明显。研究结果表明:由于高速列车齿轮传动系统服役环境的特殊性,电机扭矩、轮轨激励对齿轮传动系统振动存在显著影响,设计时须考虑负载和激励的耦合作用。

基于PCIe级联网口的农业监测视频高速传输系统研究

农业监测智慧化需要实时、高效、可靠的视频数据处理和传输方案,为了解决传统基于CPU和GPU架构的系统速率低、实时性差的问题,设计了基于Zynq架构的PCIe级联网口的高速传输系统。针对PCIe接口开发,在硬件层面,优化配置XDMA IP核参数,完成接口的数据收发引擎设计,并基于MIG 7 IP核优化配置了DDR缓存区。在软件层面,基于PCIe驱动,调度VLC软件完成视频数据读取,实现板卡和上位机之间数据的快速收发和流畅播放。针对网口协议栈的实现,利用ARM可编程特性,调度LWIP轻量级协议栈,完成TCP协议的开发,实现了网口的数据快速收发,避免了上位机CPU直接处理网络协议的时延和运算开销。此外调度AXI协议完成PCIe接口和网口的高速连通。在Zynq MZ7030FA平台上传输视频文件对系统进行速率和可靠性实测。结果表明:网口传输速率达800 Mb/s,基本实现了千兆以太网;PCIe接口的最高传输速率达816 MB/s,逼近硬件PCIe 2.0 x2的最高速率,且整个系统在应用层上实现了可靠传输。本文的研究为农业监测视频传输应用提供了高效可靠的解决方案,且系统具有较好的扩展性和推广性。

Frontier research of ultra-high-speed ultra-large-capacity and ultra-long-haul optical transmission

Ultra-high-speed, ultra-large-capacity and ultra-long-haul （3U） are the forever pursuit of optical communication. As a new mode of optical communication, 3U transmission can greatly promote next generation optical internet and broadband mobile communication network development and technological progress, therefore it has become the focus of international high-tech intellectual property competition ground. This paper introduces the scientific problems, key technologies and important achievements in 3U transmission research.

Single-side-band optical modulation in SCM systems for high-speed optical transmission

In order to decrease dispersion penalty and increase the optical bandwidth efficiency,an optical single-side-band modulation(SSBM) scheme in sub-carrier multiplexing(SCM) is proposed.The principle of the SSBM is analytically presented,and a configuration for generating optical SSB signal is proposed using a balanced Mach-Zehnder electro-optic modulator.