激光干扰技术及发展现状

激光干扰是对抗激光制导武器,保卫己方目标的重要方式.它是利用各种无源或有源设备,对各种敌方军用光电装备实施扰乱、欺骗和压制的技术.文中探讨了烟幕、气溶胶、气球等激光无源干扰和欺骗式、压制式、近炸引信等激光有源干扰的途径和方法.分析了常用武器装备系统中的车载型、机载型和舰载型的激光干扰技术.对激光干扰技术的发展现状进行综述.为研制和使用激光干扰装备的人员提供参考.     

激光无源干扰技术及其研究

激光无源干扰是对抗激光制导武器，利用各种无源设备，对各种敌方军用光电装备实施扰乱、欺骗等技术，保卫己方平台安全的重要方式。文中探讨了烟幕干扰技术、涂料伪装技术、遮障伪装技术和光电假目标技术等无源干扰的途径和方法，对激光无源干扰技术的发展现状进行了综述，为研制和使用激光干扰装备的人员提供参考。     

作战中舰载雷达干扰装备的作战使用时机

作战使用时机决策是舰载有源、无源干扰使用的基本前提。结合相关电子对抗战术理论，通过建模分析，得出了有源压制式干扰和欺骗式干扰、无源冲淡式干扰和迷惑干扰的使用时机，探讨了伪装雷达幕的作战使用。其结论对有、无源干扰装备的作战使用决策具有重要的指导意义。     

雷达无源干扰技术的发展现状

雷达无源干扰技术作为电子战的重要组成部分，在二战和历次现代战争中都发挥了巨大作用。经过几十年的发展，今天已达到相当高的水平。本文概述了雷达无源隐身、无源压制式与欺骗式干扰，以及毫米波无源干扰技术及其发展现状。     

航空武器仿真中雷达干扰效果评估模块

分析了有源干扰、无源干扰分别采取压制式干扰、欺骗式干扰对对空雷达的影响途径。从基于雷达干扰方程的功能仿真角度出发，研究了航空武器论证仿真系统中雷达综合干扰效果评估模块的各种具体数学模型，分别讨论了对搜索雷达、跟踪雷达的有源干扰和无源干扰效果模型的建立。     

有源干扰星载SAR的技术研究

主要探讨了有源干扰星载SAR的技术措施———有源压制干扰和有源欺骗干扰。有源压制干扰主要包括阻塞干扰、瞄准式干扰和随机脉冲干扰;有源欺骗干扰主要包括转发式干扰、应答式干扰和散射波干扰。定性分析了各种干扰对SAR图像影响效果并对有源干扰所需干扰功率进行了定量计算。     

试论舰载雷达干扰装备的发展方向

本文侧重阐述水面舰艇有源干扰装备战斗使用中存在的不足与问题。提出舰载电子干扰装备的发展应以舷外无源干扰装备为主，其次是有源欺骗干扰装备，再次为舷外有源干扰装备及有源压制干扰装备，并要重视发展复合式干扰装备。     

激光欺骗式干扰技术研究

激光欺骗干扰能有效对抗激光制导武器和激光测距机等激光威胁源，确保军事平台的安全。本文对激光欺骗干扰技术，包括激光测距距离欺骗干扰、激光制导武器有源欺骗干扰和激光近炸引信干扰技术等进行了分析和讨论。     

激光测距干扰与反干扰技术研究

论述对激光测距机的欺骗式干扰途径及其实现的技术要求，包括无源和有源型正偏差干扰、负偏差欺骗干扰等，建立了无源光纤激光测距干扰系统的干扰效果评估模型，着重分析和计算了其实现的技术可行性参数，得出了可行性结论。还探讨了激光测距机的反干扰措施。     

激光干扰技术现状与发展及关键技术分析

阐述了现代战争中广泛使用的激光干扰技术的分类和发展现状,分析了各种干扰技术的发展趋势,介绍了各种激光干扰技术的性能与技术特点,重点分析了激光角度欺骗干扰的功能、干扰机理及在试验实施中的若干关键技术问题.提出了一种激光角度欺骗干扰装备对激光半主动制导武器的干扰效果半实物仿真评估方法,分析了半实物仿真试验系统的功能组成及存...     

脉冲激光微能量测量

叙述了用热释电晶体测量脉冲激光能量原理,研制了热释电激光微能量探测器。采用放大、同步触发门控电路、峰值保持器和数字显示等技术,抑制了电磁场和其它干扰,使探测器灵敏度较高,最小可探测70毫微焦耳脉冲激光能量。     

高频雷达自适应波束形成抗干扰研究

高频波段上分布的大量短波信号降低了高频雷达的探测性能,需要采用自适应波束形成技术加以抑制。但是,在高频雷达的相干积累时间内,短波干扰经过电离层反射传播后通常会呈现明显的空时非平稳性。为了适应这种非平稳性,要求在相干积累时间内自适应权向量应是时变的,同时能保持杂波的相干性。提出了基于递归最小二乘(RLS)的高频雷达自适应波束形成方法。该方法兼顾了短波干扰抑制和杂波相干性保持,而且递归运行,收敛速度快,数值稳定性高。实测数据处理证明了该方法的有效性。     

Improvements in fiber-optic transmission of multicarrier TV signal

When the number of TV channels is high, a significant harmonic and intermodulation distortion arises. These distortions can be reduced by improving the modulation linearity of the laser or by applying a more appropriate modulation method. Both solutions are discussed and evaluated in detail. The linearity has been significantly improved by applying an active matching technique. The improvement achieved by the new driving circuit over the conventional one is 15 dB considering the third harmonic distortion. The sensitivity of QPSK TV transmission to disturbing interferences has been investigated. A so-called group modulation method offers a better approach for optical multicarrier TV transmission     

Multiple narrowband interference mitigation using hybrid Hermite pulses for body surface to external communications in UWB body area networks

Wireless body area networks (BAN) are primarily being designed for the detection of diseases and tracking of patients on the move. Due to its low-power requirements, ultra-wideband (UWB) has become the most preferred candidate for the physical layer of BAN. However, UWB suffers from the interferences from existing wireless networks. Again, the interference mitigation techniques developed for UWB will not be feasible for BAN because of their complexity and resulting power consumption. In this paper, we have proposed a hybrid Hermite pulse for cancelling multiple narrowband interferences. A comparison of the proposed technique with existing techniques is presented based on the operations count that highlights the lower complexity of the proposed technique. The proposed technique is also compared to Gaussian pulse based hybrid pulse in the simulation section to prove its superiority. Mathematical and simulation results prove that besides being of lower complexity the technique can mitigate the interferences satisfactorily.     

激光超声及其在无损检测中的应用

简要地介绍了目前常用的各种无损检测技术，对利用激光产生与接收超声波的原理进行了说明，着重讨论了激光超声的主要技术特点，包括其突出的优点及目前尚存在的一些问题，在此基础上，指出了这一技术几个十分重要的应用举例及今后的发展方向。     

码分双工系统中的干扰抑制技术

码分双工(CDD)是近年来新提出的一种双工方式,它支持上、下行信道同时使用同一频段。但是,由于上、下行信号可能存在较大的功率差异因而会导致较严重的相互干扰。该文针对这一问题提出了一套有效的干扰抑制和消除方案。首先,文中分析了CDD系统存在的几种干扰,在此基础上提出了基站端采用分布式天线和干扰消除器处理干扰的策略,移动台间的干扰则依靠定位技术和调度算法进行抑制。最后,计算及仿真结果证明了码分双工系统的可行性。     

Increasing acceptable number of signals in subcarrier multipleaccess optical networks in the presence of high optical beatinterference

This paper theoretically and experimentally demonstrates that our proposed method improves the carrier-to-noise ratio (CNR) of subcarriers and significantly increases the number of acceptable optical signals in subcarrier multiple access (SCMA) systems using distributed feedback laser diodes (DFB-LD's) with the same center optical frequency. This method reduces optical beat interference by using the multiplied product of the subcarriers and a low-frequency signal. From the experimental results using 1.3 μm DFB-LD's, the CNR sufficiently satisfies the required level even if the number of optical signals is three. Theoretically, the number of acceptable optical signals increases as LD's with wider optical line-width or with greater chirp coefficient are used. For example, assuming a laser chirp coefficient of 540 MHz/mA, the maximum number of LD's that can be used while still meeting the minimal CNR requirement is 12. This number corresponds to 66 optical beat interferences. Thus, this proposed beat-interference reduction technique is very effective in SCMA systems using DFB-LD's without optical frequency control     

Chromatic Dispersion Monitoring Technique Using Pilot Tone Carried by Broadband Light Source

We propose and demonstrate a simple chromatic dispersion monitoring technique based on the pilot tone generated by a broadband light source (BLS). Previously, the pilot tone has been obtained by directly modulating each transmitter laser with a small sinusoidal current. Thus, for use in the wavelength-division- multiplexed (WDM) network, each transmitter should be modulated with a unique pilot tone. However, we obtain the pilot tone by modulating an additional BLS such as a reflective semiconductor optical amplifier. Thus, there is no need to modulate each transmitter laser. We evaluate the performance of the proposed technique in an 8$, times ,$10 Gb/s WDM system. The result shows that, unlike the conventional pilot-tone-based monitoring technique, the performance of this technique is almost insensitive to the polarization-mode dispersion.      

An eigenanalysis interference canceler

Eigenanalysis methods are applied to interference cancellation problems. While with common array processing methods the cancellation is effected by global optimization procedures that include the interferences and the background noise, the proposed technique focuses on the interferences only, resulting in superior cancellation performance. Furthermore, the method achieves full effectiveness even for short observation times, when the number of samples used for processing is of the the order of the number of interferences. Adaptive implementation is obtained with a simple, fast converging algorithm