一种针对转发式欺骗干扰信号的负延时补偿方法

针对卫星导航转发式欺骗干扰中转发信号存在负延时需求而工程上又无法实现的问题,提出了一种负延时补偿方法。该方法根据预设欺骗位置,通过转发式欺骗干扰延时算法,获得各卫星信号通道所需转发延时量;然后基于接收机钟差最小化原则选取最优的延时修正量添加到所有通道的转发信号中。理论分析和仿真结果表明,该方法不影响接收机的定位结果,消除了负延时无法实现的问题对转发式欺骗干扰的限制。     

High-speed and low-power repeater for VLSI interconnects

This paper proposes a repeater for boosting the speed of interconnects with low power dissipation. We have designed and implemented at 45 and 32 nm technology nodes. Delay and power dissipation performances are analyzed for various voltage levels at these technology nodes using Spice simulations. A significant reduction in delay and power dissipation are observed compared to a conventional repeater. The results show that the proposed high-speed low-power repeater has a reduced delay for higher load capacitance. The proposed repeater is also compared with LPTG CMOS repeater, and the results shows that the proposed repeater has reduced delay. The proposed repeater can be suitable for high-speed global interconnects and has the capacity to drive large loads.     

An Experimental 800 Mbit/s Four-Level Repeater Compatible with the 60 MHz Analog System

The design and performance of an experimental 800 Mbit/s repeater for four-level digital transmission over a coaxial cable is described in this paper. The 800 Mbit/s digital system exceeds the 60 MHz analog system, both in capacity and in economy. The repeater is designed to operate in repeater housings located at 1.6 km maximum spacing to be compatible with the 60 MHz analog sytsem. A nonredundant four-level line code has been employed, using a newly developed quantized feedback dc restoration technique. The most important item in realizing the high-speed multilevel repeater is the reduction of intersymbol interference. A simple quantized feedback scheme and an adjustable three-tap transversal equalizer have been used to compensate for intersymbol interference. The experimental repeater has been tested for 1.1-1.7 km repeater spacings using 2.6/9.5 mm coaxial cable. The results show that an 800 Mbit/s repeater with 1.6 km maximum repeater spacing is feasible.     

基于FPGA的100BASE-TX工业以太网中继器的设计与实现

为了提高工业以太网的实时性和确定性,设计出一种基于FPGA的以太网中继器。与传统的以太网中继器相比,该中继器采用FPGA芯片实现数据的处理,具有延时小的特点。该中继器以太网接口部分采用专业的以太网PHY芯片,数据的转发则由FPGA来完成,FPGA程序包括同步检测模块、同步再生模块、双口RAM及中央控制模块等几个模块。实验结果表明,该以太网中继器能兼容IEEE802.3标准以太网设备,与传统的以太网中继器相比,延时要小很多。     

Reducing Interconnect Delay Uncertainty via Hybrid Polarity Repeater Insertion

Capacitive crosstalk between adjacent signal wires has significant effect on performance and delay uncertainty of point-to-point on-chip buses in deep submicrometer (DSM) VLSI technologies. We propose a hybrid polarity repeater insertion technique that combines inverting and non-inverting repeater insertion to achieve constant average effective coupling capacitance per wire transition for all possible switching patterns. Theoretical analysis shows the superiority of the proposed method in terms of performance and delay uncertainty compared to conventional and staggered repeater insertion methods. Simulations at the 90-nm node on semi-global METAL5 layer show around 25% reduction in worst case delay and around 86% delay uncertainty minimization compared to standard bus with optimal repeater configuration. The reduction in worst case capacitive coupling reduces peak energy which is a critical factor for thermal regulation and packaging. Isodelay comparisons with standard bus show that the proposed technique achieves considerable reduction in total buffers area, which in turn reduces average energy and peak current. Comparisons with staggered repeater which is one of the simplest and most effective crosstalk reduction techniques in the literature show that hybrid polarity repeater offers higher performance, less delay uncertainty, and reduced sensitivity to repeater placement variation.      

实施转发式GNSS欺骗干扰的功率控制策略研究

在实施转发式欺骗干扰时,经转发的干扰信号和直达信号同时进入被干扰接收机,对接收机的信号处理过程造成复杂的影响.转发式干扰根据信号功率的大小,其干扰效果可能会出现信号压制、信号欺骗或无法欺骗等多种情况,目前尚无文献对转发干扰信号功率控制进行定量研究.为推进转发式欺骗干扰在导航战中的实际应用,制定合适的转发式欺骗干扰功率控...     

Repeater Fault Location for a Submarine Optical Fiber Cable Transmission System

This paper introduces a repeater fault location system for a repeated submarine optical fiber transmission system of 400 Mbits/ s at 1.3μm. The repeater fault location system is used in an out-of-service test. The fault locator transmits a test signal via a main optical fiber line, in order to make a loop-back path in one of the repeaters for returning the test signals via another main optical fiber line and to measure the bit error rate (BER) of the interrogated repeater. The test signal is a kind of pseudorandom signal that includes a low frequency component, which is assigned to the repeater as a supervisory frequency tone (SVT) signal. The BER is measured by counting the number of low frequency signal phase inversions in a time. This paper first describes the test signal generating method, SVT frequency allocation, and the filter design installed in a repeater. Next, there is a discussion of how the capability of the repeater fault locator has been experimentally verified by using two submarine repeaters, including four regenerative repeater units and three submarine optical fiber cables. As a result, a BER of less than5 times 10^{-6}is accurately measured.     

转发式欺骗干扰时延控制算法

无人机卫星导航欺骗技术在现代导航战中越来越受到广泛的关注，其中转发式欺骗干扰因其无需获得信号结构的先验知识，在军码导航领域比生成式欺骗干扰更具使用价值。目前的军码转发信号普遍以转发接收天线点的位置坐标作为基础进行定点静止转发，在对无人机欺骗干扰时，信号置信度不高，干扰效果不佳。提出一种转发干扰时延算法，根据转发坐标需求计算不同卫星信号的时延量，可根据欺骗策略实时调整转发坐标，提高干扰成功率。最后通过实验验证，提出的时延算法得到的转发坐标误差在米级范围，验证了算法的正确性。     

一种针对用户GNSS时钟的转发式欺骗方法

全球卫星导航系统(Global Navigation Satellite System,GNSS)转发式欺骗干扰具有系统搭建容易、干扰实施方便、成本低等优点,目前已成为一种重要的GNSS欺骗方式。针对多峰值抗转发欺骗干扰检测算法,提出一种针对目标接收机GNSS时钟的转发式欺骗干扰方法。相比于传统转发式欺骗的各通道卫星信号时延一致的特点,该方法根据待欺骗接收机和转发式欺骗源的位置计算各卫星通道转发时延,使待欺骗目标接收到的GNSS欺骗信号的时延为伪码周期整数倍,并随时间自适应动态调整转发时延,使得欺骗检测失效,进一步欺骗静态目标接收机的GNSS时钟。模拟实验和仿真实验验证了该转发式欺骗方法的有效性。     

移动通信系统中光纤直放站的设计

移动通信系统引入光纤直放站后使基站接收端的噪声发生变化,通过对光纤直放站之间的传输距离分析以及引入光纤直放站后基站接收端的噪声变化分析发现,噪声增量主要由直放站增益和基站发射机至直放站的路径损耗决定,并进一步推导出光纤直放站的上行增益应比路径损耗小8 dB,而其下行增益的设计应充分考虑到系统上下行的平衡。最后,设计了系统噪声系数为3 dB,上行增益为30 dB,下行输出功率设为36 dBm的光纤直放站。实际投放后发现,网络盲区的比例减小到3.18%,说明该直放站的效果相当显著,并且性能稳定,与原基站兼容性好。     

Over 10 Gb/s regenerators using monolithic ICs for lightwavecommunication systems

The design and performance of repeater circuits based on Si and GaAs MESFET process technologies are described. Repeater circuits were designed and fabricated for around 10 Gb/s repeater systems using Si and GaAs IC processes. The Si ICs operated up to 9 Gb/s, and the GaAs ICs exceeded 10 Gb/s. It was verified that regenerative repeater systems using these ICs and optical amplifiers exhibit a stable operation at 10 Gb/s. The performance of the 10 Gb/s repeater using these monolithic ICs and photonic circuits is discussed     

对线性调频脉冲压缩雷达的多载波调制转发干扰

目前对线性调频(LFM)脉冲压缩雷达转发欺骗干扰主要通过移频调制转发和采样直接转发实现,常规转发干扰样式简单,干扰信号规律性强、复杂度低。该文提出一种基于间歇采样的多载波调制转发新型干扰样式。首先引用码片的概念对间歇采样过程重新建模,在此基础上,通过对当前采样码片附加不同移频量,结合多载波并行调制体制对其进行串并转换,利用不同次转发信号各子载波间的干扰累积,实现对LFM脉冲压缩雷达的数量、幅度、空间分布可控的逼真假目标干扰。仿真表明该干扰样式比移频干扰和直接转发干扰具有更好的干扰效果。     

On-board regenerative repeaters applied to digital satellite communications

In pulse-code modulation/time-division multiple access (PCM/TDMA) satellite communications, though the number of repeating stage is usually only one, the regenerative repeater will be worthwhile enough to be introduced on board the satellite. This is because the improvement of the communication quality by the increase of the transmission power is difficult in the satellite link and the regenerative repeater is very effective for removing cochannel interferences which will become predominant factor of signal degradation in the future and it will also provide great facility for various kinds of on-board processings. This paper first presents basic configurations of the on-board regenerative repeater, and discusses about simplification of the repeater. Next various kinds of on board processings ate discussed in connection with the regenerative repeating. Then a concrete regenerative repeater applied to satellite switched/TDMA (SS/TDMA) satellite system which augments the communication capacity by frequency reuse is presented and compared with the conventional frequency translating type in terms of link budget, power dissipation, and weight. Lastly the result of the development of an experimental regenerative repeater is described.     

Communication satellite processing repeaters

Two kinds of processing repeaters which may find application on communication satellites in the near future are described. The type I repeater allows access only if the transmitted signal contains a predetermined code structure. This serves three purposes: first, unauthorized users are excluded, second, co-channel interfering signals are not retransmitted on the downlink, so as not to waste a portion of the satellite transmitter power, and, third, removal of the interference signal at the satellite avoids having to do this at the ground receiving terminal. Thus such a repeater would find particular application where there are a large number of ground receiving stations. The type 2 repeater routes signals received at its N input terminals to be transmitted at N output terminals, thus acting as a "switchboard in the sky." Two purposes are served: first, the satellite capacity is more fully utilized in the presence of fluctuating traffic demands, and, second, single-frequency transmission and reception are possible for user ground stations, thus simplifying these stations and still allowing communication to any station in the network. It is established when the type 1 repeater is able to increase the satellite communication capability beyond that of a simple repeater and further that fairly simple filtering is sufficient on the satellite. For the type 2 repeater, a proposed frequency control plan minimizes the filtering required on the satellite where frequency division multiplex is used and reduces the amount of switching required on the satellite to N single-pole N-throw switches where time division multiplex is used without the requirement of any memory on the satellite. A summary of present-day translating repeaters, as used in the Intelsats III and IV and DSCS II satellites, is included.     

Determining Repeater Margin with a Stub and Attenuator

The margin of a high-speed digital regenerative repeater can be determined easily by adding a misterminated stub at the repeater input. The stub adds an interfering signal which, if large enough, will cause the repeater to make errors. The amplitude of the interfering signal is determined by the termination, so the termination impedance at which errors begin is a good measure of repeater margin. No calibration procedure is required.     

间歇采样转发干扰压制效果分析

分析了间歇采样转发干扰原理及其不同形式,由于间歇采样转发干扰机理不同于传统的噪声压制干扰,提出了一种基于恒虚警检测的间歇采样转发干扰压制效果分析方法,并利用仿真实验进行了验证。实验表明,该方法能够正确分析间歇采样干扰压制效果。     

GSM变频直放站的优化设计

本文介绍了GSM直放站的应用价值,以及变频直放站的发展前景.并介绍了一种本振集成于混频器中直放站优化设计方案,这种设计方案既可以减少设计的难度和调试的过程,又可以减少在电路中的彼此信号干扰.为变频直放站的设计和应用提供更优的方法.     

GPS转发欺骗式干扰时延控制算法研究

针对导航对抗中的欺骗干扰问题,在讨论对 GPS 制导目标实施转发欺骗式干扰可行性的基础上,建立了转发欺骗式干扰时延决策模型,推导得到转发时延算法,同时对转发干扰后的接收机钟差变化进行了分析,给出减小钟差变化的途径,最后通过仿真计算验证了转发时延算法的有效性,并给出了采用四站和单站转发适用的干扰目标。     

Automatic on-off switching repeater for DS/CDMA reverse linkcapacity improvement

We propose an automatic on-off switching (AOS) repeater that is switched off automatically when there is no active user within its coverage. With the AOS repeater, we can reduce the unnecessary noise enhancement. The reverse link capacity of a DS/CDMA system with AOS repeaters is analyzed mathematically and compared with that of a system with conventional repeaters. Also, the AOS circuit in a repeater can protect the reverse link capacity of a DS/CDMA system from excessive noise enhancement by abnormal repeaters. From the numerical results, noticeable improvement with the AOS repeaters is shown     

Error Margin Estimating in Repeaters

In this paper a new method of estimating error margin inTcarrier repeaters is proposed. This estimate is based on two sets of data: (a) measurements from a commonly used test wherein bipolar violations are inserted into the line at an audio rate, and (b) the crosstalk environment in which the repeater is operating. An audio component due to violations in the bipolar signal causes a shift in the eye pattern resulting in a change of repeater error rate. This in turn changes the regenerated audio signal power by an amount depending on the initial undisturbed error rate of the repeater. This then gives a basis for extrapolating the operating error rate of a repeater from a test measurement. This error rate combined with a knowledge of the cable crosstalk parameters and number of operating systems during the test, is then used to estimate the error margin or eye opening of the repeater, assuming a Gaussian distribution for the interference. A method of ranking repeaters in a repeatered line to indicate their relative margin is proposed wherein the effect of errors on the audio signal to an intermediate test repeater is taken into account. Results presented are quite general and valid at any line rate and repeater spacing, and hence applicable for differentT-carriers such asT1, T1C, T2, etc.