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双语推荐：多径干扰

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文章介绍了民航甚高频地空通信的视距传播的特点,通过数学模型阐述了多径干扰的形成条件和对通信造成的影响,分析了多径干扰导致信号衰落出现的位置与地面站天线高度和飞行高度的关系,通过确定地面主反射点,计算地面天线高度与多径干扰时延的关系,探讨了天线高度对多径干扰时延的影响,研究如何抑制多径干扰。
This paper introduced the line-of-sight propagation characteristic of civil aviation VHF(very-high-frequency) radio system and explained the forming conditions of multipath interference and its influence to the system by the mathematical model. And also the relation between signal fading point caused by multipath interference and antennas height, aircrafts altitude is analysed. After that we analysed where the main reflected points were and calculated the delay time of multipath reflections from the main reflected points to the antennas of different height. In the end we discussed about the influence of antenna height on the delay time of multipath interference and the way how to reduce the multipath interference.

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在暗室中对天线进行测量时,来自暗室侧壁、后墙的多径干扰会影响测试精度。因此多径干扰成为影响天线测量精度的主要因素之一。为此,提出利用距离差分法消除天线测试时的多径干扰,达到去除多径干扰的目的。并通过数值仿真验证了该方法是行之有效的。
When the antenna is tested in the anechoic chamber,the test precision is affected by the multipath signals coming from the side wall and back wall of the anechoic chamber. Multipath interference has become one of the main factors in-fluencing the antenna test precision. Therefore,the distance difference method is proposed in this paper to eliminate the multipath interference in antenna testing. The result of the numerical simulation proved the validity and reliability of this method.

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机场周边复杂的电磁反射环境引起的多径效应降低了微波着陆系统的导航精度,严重影响飞机着陆安全。以往的抗多径干扰方法多是基于场地环境的电磁建模实现,存在计算量大、设计复杂等问题。为了有效抑制多径干扰的影响,提出了一种对机载导航设备接收的脉冲信号直接进行数字处理的方法,在倒谱域进行信号分析检测,直接抵消多径干扰的影响,估算出往、返扫描脉冲的时延差,从而实现进近飞机角度位置的精确计算。仿真结果表明,该方法能够有效抑制多径干扰引起的微波着陆系统的测角误差。
The multipath effect resulted from the complicated electromagnetic environment around the airport reduces the navigational accuracy of microwave landing system,which threatens the landing security of planes seriously.But the previous multipath interference suppression methods are realized mostly on the electromagnetic modeling of the airport environment,which have the problems of huge computation and com-plicated design.A data processing method is proposed to process the pulse signal received by the avionics of the approaching airplane.The multipath effect is counterbalanced by using cepstrum technology and the time delay of the to and fro scanning beams is estimated directly.Thus the accurate navigation of microwave land-ing system is achieved.It is proved by the simulation result that the angle error of the measurement caused by the multipath can be suppressed effectively.

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针对传统宽带多径干扰抑制波束形成算法计算量大、稳健性差的问题,提出一种基于均匀直线阵的稳健宽带多径干扰抑制波束形成算法。当期望信号垂直入射时,该算法首先在波束旁瓣区域引入虚拟干扰源构造能量聚焦矩阵,通过主瓣宽度的迭代处理,整体控制输出波束旁瓣级,将旁瓣区域能量聚焦到主瓣区域,实现多径干扰条件下的宽带波束形成;然后对期望信号和辅助方位角施加相位响应约束,将其扩展至期望信号非垂直入射和存在指向误差的情况,与传统宽带多径干扰抑制波束形成算法相比,在提高算法稳健性的同时大大降低了计算复杂度;最后仿真分析与实际数据验证表明,该算法能够有效的抑制多径干扰,稳健性较好且具有较高的输出信干噪比。
In order to solve the computational complexity and robustness problem of traditional wideband multipath inter-ference suppression beamforming algorithms,a robust algorithm based on uniform linear array is proposed.First of all, when the desired signal normal incidence,this algorithm introduces virtual interferences in sidelobe region to construct en-ergy focusing matrix,and wholly controls the output beam sidelobe level by iterative processing of mainlobe,then it focuses sidelobe energy to mainlobe to achieve wideband beamforming in multipath environment.Furthermore,this algorithm is ex-tended to the case of desired signal non-normal incidence and direction error existing,through imposing phase response constraints to desired signal and auxiliary azimuth.Comparing with the traditional algorithms,the proposed algorithm has lower computational complexity and better robustness.Finally,the simulation and actual data analysis results show that the algorithm can suppress the multip

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多径干扰不具备空间相关性,难以通过差分方法消除,是影响全球导航卫星系统定位精度的关键因素之一。从接收机处理的导航信号受前端带宽限制以及近距离多径干扰更需抑制两个角度出发,提出了一种基于多门延迟(MGD)结构的多径干扰抑制方法,推导了带宽受限时MGD结构的多径误差的数学表达式,以加权和非加权多径误差包络面积最小作为目标函数,优化了该结构中早迟门系数,并以典型导航信号SinBOC(10,5)为例来说明该方法的性能。结果表明:对于SinBOC(10,5),该方法多径误差包络面积小于高分辨率相关器(HRC)方法至少15%;当前端带宽较大时,该方法对于较小和中等延迟的多径信号的抑制能力优于HRC方法。
Multipath interferences which are difficult to be eliminated through the differential method be-cause they are not interrelated in space,affects the positioning accuracy of global navigation satellite sys-tems(GNSS). The navigation signals in the receiver are affected by the front-end bandwidth,and the close multipath interference suppression has more practical significance. From the two aspects a multipath inter-ference suppression method based on multiple gate delay(MGD) is proposed in this paper. The multipath error mathematical expressions of the MGD method under limited bandwidth are derived,the early-late gate coefficients of the MGD are optimized by minimizing the areas closed by the weighted and non-weighted multipath error envelopes,and the typical navigation signal SinBOC (10,5) is chosen as an example to il-lustrate the performance of the method. The results show that for SinBOC(10,5) the area closed by the multipath error envelopes of MGD method is less than that of the hig

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针对现代海上通信系统中多径信道以及海面多变天气引起通信信号干扰问题，研究了当前处理多径干扰的盲信号均衡技术，针对 MPSK调制信号，改进了盲检测信号的权阵函数算法，并利用 Matlab的针对通信系统专用仿真工具Simulink搭建了仿真平台。本文最后给出了不同信噪比条件下，该改进算法仿真得到的误码率曲线图。实验表明，该改进权阵函数算法能有效降低海上通信多径干扰以及海面噪声干扰，提高海面通信系统精度性。
Multipath channel interference and communication signal interference caused by changeable weather on sea affect the performance of maritime communication system. This paper studies the blind equalization technology, and a improved algorithm is also proposed and researched in this paper. At last, a maritime communication system model was used in Simulink condition, and the whole simulation model was set up. The simulation results show that the improved algorithm can well test out all kinds of MPSK signals, and have strong adaptability in MPSK signals.

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伪码跟踪多相关器技术广泛应用于导航接收机抗多径和导航信号质量监测。论文通过对比分析多径和多址信号对导航信号相关峰畸变的影响,揭示了多相关器技术可用于多址干扰抑制。通过仿真分析了多址误差随期望接收信号与干扰信号功率差和载波多普勒频率差的变化规律,并与传统的并行多址干扰对消方法进行了对比。仿真结果表明当多址干扰信号功率差小于10d B时,ELS和Double-delta与单级并行干扰对消方法的性能相当,但是实现复杂度大大降低。
Multicorrelator techniques for PN code tracking are widely used in navigation receiver for multipath mitigation and navigation signal quality monitoring.By comparing the effects of multipath signal on the navigation signal correlation peak distortion with that of multiple access signal,this paper reveals that the multicorrelator techniques can be used for multiple access interference suppression.The variance of multiple access interference errors with various power difference and carrier Doppler frequency difference between the desired signal and the interference signal is analyzed through simula-tion,and compared with the traditional parallel interference cancellation methods.Simulation results show that when the power difference between multi-access interference signal and desired signal is less than 1 0dB,the performance of ELS and Double-delta techniques is the same with the single-stage parallel interference cancellation method,but the implementation complexity is greatl

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浅海信道是一个多径信道，对于基于相关法的延迟估计，多径效应常常会导致相关函数中出现伪峰，伪峰的幅度有时会超过主峰，进而增加了相关峰选取的难度。利用 AR 法滤波对信号中的多径分量加以抑制，从而削弱了伪峰的幅度，提高了延迟估计的准确性。先从理论上论证了线性预测法可以对多径干扰进行抑制，再用仿真信号和实际信号验证了方法的效果。对于仿真信号，在无噪声干扰的条件下，选择合适阶数的滤波器可以使信号中的多径分量被完全抑制；对于正信噪比的实际信号，其中的多径分量在一定程度上被抑制，从而由多径分量产生的相关峰会被明显削弱，减少了峰值位置的跳变。
Shallow water channel is a multipath channel. For time delay estimation of cross-correlation method, multipath effects usually lead to secondary peaks, of which the magnitude may be larger than the main peak of the correlation function. And, this increases the difficulty of choosing the right peak. In this paper, AR filter is used for eliminating the multipath components and softening the secondary peaks to increase the accuracy of time delay estimation. Theoretical analysis proves that the linear prediction method can eliminate the multipath effect, and then the effect of this method is testified with both simulated and real signals. For simulated signals, the linear prediction method with appropriate orders can completely eliminate the multipath components of the original signals. For real signals with positive SNR, the mul-tipath components can be eliminated to a certain extent, thus the secondary peaks caused by multipath components will be significantly softened and main peak shif

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网络系统具有多径状态多输入及多输出的特点,干扰源复杂,网络安全受到多状态参量影响。PID控制理论具有多状态输入输出MIMO特性,提出一种基于PID多径网络控制理论的网络终端多元干扰监测方法,以PID控制理论为基础构建网络终端动态干扰监测系统软件,结合PID网络结构的动态神经元扩展功能,在线自适应调节控制误差,动态实时捕捉多状态网络入侵数据,剔除入侵干扰信息,保证了网络终端的安全。仿真实验表明,监测方法能有效对多元网络入侵数据进行检测和滤除,检测正确率高,能有效防止漏报和误报,多径PID控制网络控制系统学习速度快,终端形成的三通道结果显示,系统能有效实现对网络信息的动态多元监测。设计成果在网络安全防御领域具有很强的实用性。
The network security protection and anti disturbance and the network monitoring were researched. A new net-work multi-interference monitoring method was proposed based on Multipath PID control theory. The intrusion detection al-gorithm was designed for multiple intrusion interference, and the intrusion monitoring software was designed. The intrusion data was captured, and the interference information was filtered for the network security. Simulation result shows that the detection and monitoring performance is good with effective detection and filtering property, the detection rate is nice. And it can prevent the false positive and false negative. The learning speed is high, and the three channel terminal detection re-sult shows that the system can realize the dynamic multivariate monitoring. The design result has good value in network se-curity protection application.

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超宽带通信过程中,容易受到宽带噪声干扰、部分频带噪声干扰、脉冲干扰、单音干扰、多音干扰、扫频干扰和跟踪干扰,提高了多径传播的误码率。提出一种抗干扰的超宽带天线网络组网方法,通过分析干扰源的原理,运用随机跳跃模型对通信中的传感器设定速度,再设计一种随机路点模型随机选择路点的纬度θ和经度φ实现球面的优化覆盖,保证节点的最大抗干扰性能,实现优化通信。实验证明,这种方法能够提高超宽带通信中多径传播的准确率,满足超宽带通信的准确性要求,取得了满意的结果。
Ultra-wideband communication process, vulnerable to broadband noise interference, part of the band noise, pulse interference, tone interference, polyphony interference, sweep frequency interference and tracking interference, makes the multipath propagation error rate is higher. This paper puts forward a anti-interference ultra-wideband antenna network networking method, through the analysis of the principle, and using random jumping model of communication of the sensor setting speed, in the design of a random way point model random selection way point of latitude and longitudeψ ? to realize the optimization of the spherical cover, to ensure that the biggest node anti-jamming performance, realizing the optimized communication. Experiments show that the method can improve uwb communication multipath propagation accuracy, and meet the uwb communication accuracy requirement, and satisfactory results were obtained.

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