干扰条件下地域通信网链路阻塞率研究

链路是通信网络的重要组成部分。在干扰条件下,从理论上建立链路模型,并根据链路的分类和信道的误码率对链路阻塞率进行了研究。在此基础上,文章给出了某地域通信网一个四节点网络干扰时的链路选择示例,并进行了仿真。     

卫星通信物理层非直扩链路的单音干扰影响解析

针对卫星通信传输链路中常见的单音干扰,以典型的卫星通信物理层非扩频传输波形为对象,建立单音干扰下的链路传输模型,分析单音干扰频率、相位和功率等参数对链路传输性能恶化程度的影响,理论推导链路传输误码率与频率差、信干比之间的闭合数学关系式.通过不同单音干扰条件下的卫星通信物理层链路传输性能仿真,得到误码率随频率差和信干比的...     

通信干扰误码率分析与仿真

随着军事信息在现代战争中作用的不断提高,以扰乱或破坏信息传输为目的的通信干扰的作用和地位也不断提高。误码率是衡量干扰有效性的一个重要指标。推导了不同干信比条件下的误码率公式,并仿真分析了不同干信比情况下的误码率曲线,有助于有效选取干扰样式。     

基于ADS仿真的最佳干扰信号分析

为了研究不同类型干扰信号对特定通信链路的干扰效果，应用ADS软件，通过调用多种DSP电路功能模块，在成功搭建PM调制通信链路的基础上，通过注入多种类型干扰信号，研究了基于特定通信链路误码率随不同类型干扰信号的信干比变化情况，以及当干扰信号采用不同码速率时，对通信链路误码率的影响，并针对仿真结果进行了理论分析。通过统计计算，结合通信链路各个关键节点处信号频谱的分布变化，得出信号解调过程中的频谱搬移与杂散信号的伴随出现，低通滤波器对带外信号的强抑制作用，以及采用较高码速率的通信干扰信号，其频谱扩展导致干扰效果不佳等结论。该研究可以进一步丰富ADS软件的应用场景，仿真结论可以指导通信干扰策略的制定。     

噪声干扰对DSSS调制系统对抗效果仿真研究

随着电子对抗技术的飞速发展,通信对抗装备愈来愈广泛地用于电子对抗领域。结合通信对抗装备技术特征,本文重点研究采用 DSSS(直接序列扩频)调制技术的通信装备在以噪声干扰为主要方式对抗条件下,误码率与干信比、信噪比之间的关系,得到了在同等条件下, 部分频带干扰效果优于宽带干扰效果的结论,该结论对进一步深入研究干扰技术和干扰效果具有参考价值。     

基于地域通信网流量攻击方法的仿真研究

地域通信网中各节点之间的正常通信是保障作战胜利的关键,由于地域通信网中各节点间的连接多采用无线链路,可以使用流量攻击的方法对链路进行攻击,使各节点通信中断。在分析流量控制和拥塞控制的基础上,结合OPNET仿真软件建立网络模型,通过仿真研究验证了流量攻击法可以有效地使地域通信网通信中断,达到攻击的目的。     

地域通信网干扰效果评估指标研究

目前地域通信网是战术通信网的主体和主要发展方向。介绍了地域通信网的特点,分析了对地域通信网的干扰方法。针对地域通信网的工作特性,提出了采用误码率和网络阻塞概率作为对地域网干线节点干扰的效果评估指标,最后以四个节点组成的栅格状地域通信网作为研究对象,采用数学仿真方法对多种情况下的误码率、网络阻塞概率进行了仿真评估。     

地域通信网链路威胁评估研究

链路威胁评估是进行干扰资源分配的基础.针对目前新型干扰技术出现的新情况和对网络重要链路实施干扰的新需要,首先分析了现阶段针对地域通信网的3类干扰技术,在此基础上,给出了通信网络环境下评估链路威胁的指标体系,并采用基于路径的方法对链路战术重要性进行了计算,最后运用多属性决策方法在具体网络场景下对链路威胁等级进行了评估计算...     

短波FH/OFDM通信系统抗跟踪式干扰性能分析

对于短波多载波跳频通信系统,跟踪式干扰是一种有效的干扰模式。分析了正交频分复用( OFDM)部分子信道干扰与符号误码率的关系,通过仿真获得了最佳跟踪干扰的部分时间参数,结合OFDM频谱结构与干扰频谱关系,推导了高斯信道条件下部分频带干扰和多音干扰时系统误码率,分析了短波FH/OFDM通信系统抗跟踪式干扰的误码率性能,仿真结果表明：跟踪干扰时间窗口对误码率的影响与部分频带干扰因子和信干比有关;在部分频带干扰与部分时间干扰之间,存在等效的干扰效果区域;多音干扰因子越大,系统所受影响越大,跟踪干扰时间窗口对误码率的影响与多音干扰因子和信干比有关,针对OFDM符号的多音干扰影响要远大于部分频带干扰的影响;跳频与OFDM技术的结合、提高载波跳速、减小跟踪式干扰对OFDM符号的影响,也是消除多音干扰的重要手段。     

卫星通信QPSK调制链路的干扰影响分析

针对卫星通信所面临的不同类型的敌意干扰,以QPSK调制的传输波形为研究对象,分析了单音、多音、扫频及窄带噪声等4种干扰的频域特征,理论推导了几种干扰对应的QPSK接收符号表达式,分析干扰对接收符号星座图的影响。通过完整链路仿真得到不同干扰对应的QPSK解调星座图和误码率曲线,表明干扰对星座图产生不同形状的恶化,在信干比大于5 dB时窄带噪声干扰对系统恶化程度最严重,而在低信干比时单音干扰恶化程度最严重。理论推导和仿真结果提供了不同类型干扰不同干信比情况下,对QPSK调制传输系统的恶化程度,为卫星通信链路抗干扰奠定了良好基础。     

一种Ka频段卫星数据链同步干扰研究

针对Ka频段某卫星数据链,首先介绍了其信道特性及编码对系统误码率的影响并给出了其误码率计算公式,然后通过对其同步字的出现频率的分析,给出了相应的干扰方式,仿真结果表明,在干信比较低时,该干扰方式仍然能够取得很好的干扰效果,同时具备一定隐蔽性。     

Node to Node Performance Evaluation through RYU SDN Controller

In this paper a novel jamming technique is presented. The idea of the proposed jamming technique is based on adding inphase and quadrature impairments to the jamming signal. The jammer is simply a quadrature phase shift keying signal. The bit error rate probability (BER) of the proposed jamming signal is derived analytically and validated with the aid of the software defined radio SystemVue design software. The standard multi input multi output (MIMO) wireless local area network (WLAN) IEEE802.11n communication system is chosen as the victim system. Its BER performance is simulated in the presence of the proposed jamming signal in multipath fading channel. Finally, the efficiency of the proposed jamming signal on the MIMO WLAN IEEE802.11n communication system is practically measured in the laboratory where a practical experiment is held and the efficiency of the proposed jamming signal is compared with the traditional single tone jamming signal. It will be shown practically that the proposed jamming technique outperforms the traditional single tone jamming signal by nearly 15 dBm on the impact of efficiently jam the MIMO WLAN IEEE802.11n communication system.

     

针对3G-ALE系统同步头的灵巧干扰

研究了针对第三代短波通信网自动链路建立（3G—ALE）系统同步头的干扰原理,提出了相应的灵巧干扰信号的设计准则,依照该准则设计了两种实用的针对同步系统的干扰信号。仿真结果表明,灵巧干扰信号对同步系统的破坏能力远远高于常规干扰。在相同干扰效果的条件下,使用灵巧干扰所需的干信比小于常规干扰方法约7dB。     

无人机对IMSE通信干扰仿真研究

基于高层体系结构（HLA）技术,设计了无人机对改进型移动用户设备（IMSE）通信干扰仿真系统,利用该仿真系统进行了仿真,得出了无人机采用不同飞行高度进行通信干扰时IMSE网络性能的指标参数,为研究无人机对IMSE实施通信干扰效果提供了一种有效的方法。     

电路和分组交换的抗干扰能力分析

随着军事信息在现代战争中作用的不断提高,以扰乱或破坏信息传送为目的的通信干扰的作用和地位也随之不断提高。通过对电路交换网络和分组交换网络在被干扰的情况下在物理层、链路层、信令和协议,以及通信业务的影响进行了分析和对比,得出在强干扰模式下网络保障性能大体一致,但是在某些条件下反应的特性分组网络略强。最后指出通信系统本身技术体制的选取是其抗干扰能力好坏的一个重要因素。     

一种基于误码率分析的无线通信网干扰效能评估方法

随着现代通信技术的发展,通信干扰的对象已由单一信号源转向通信网。为了有效评估对无线通信网的干扰效能,在构建通信网干扰模型的基础上,提出了一种基于传统误码率理论的无线通信网干扰效能评估方法,并进行了干扰效能评估仿真。仿真结果验证了该方法的科学性和可行性,表明了对干扰组资源采用适度倾向性分配方式能够提高对通信网的干扰效能,在实际对抗中对通信网实施有效干扰具有重要的指导意义。     

Performance Analysis of Free Space Optical Networks Using the Beta-Average Recursive Estimator

The present paper aims to investigate and analyze the performance of a point-to-point optical network under a free-space optical (FSO) communication system. Free-space optical communication is a sophisticated technique that has been employed as a channel model of optical wireless communication to transfer large amounts of data at high speeds. However, two important issues, that could affect the source of the FSO link, have been added. The first one is related to chromatic dispersion which is attributed to the chirping phenomenon of the optical signal; the second issue concerns the secondary jamming power that can be generated by some Radio Frequencies from base stations. It is important to note that the effects of atmospheric turbulence, misalignment fading, and atmospheric attenuation as well as geometric losses were also taken into account. The purpose of this research work is to overcome these effects, in order to increase the data transmission rate from 1.25 to 50 Gbps in the proposed system. Consequently, a very efficient solution is suggested to correct these problems and to make the FSO link more reliable using the Beta-Average Recursive Estimator. In addition, the numerical results obtained are presented for the purpose of validating our proposal through the evaluation of the performance of a transmission link in terms of the bit error rate and Q-factor. In the end, the resulting conclusions are listed, explained and discussed.

     

Performance of Chaos-Based Digital Communication Systems in the Presence of a Pulsed-Noise Jammer

Chaos-based communication systems are known to offer advantages that are shared by spread-spectrum communications. One important aspect of the performance of any spread-spectrum communication system is the ability to resist jamming. In this paper, an analysis of the antijamming performance of a coherent chaos shift keying system under the influence of a common pulsed-noise jammer is presented. Two types of pulsed-noise jammers, slowly switching and fast switching jammers, are considered in our studies. The performance is evaluated in terms of the bit error rate (BER) under different levels of noise power, jamming power, spreading factor, and duty factor. The maximum (worst-case) BERs are also obtained analytically for the case where the jammer is slowly switching. Computer simulations are performed to verify the analytical results. Finally, the BERs are compared with those of a conventional direct-sequence spread-spectrum communication system.