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高宇宁 《智能计算机与应用》2021,11(6):100-103
在分布式网络传输中,受到码间干扰容易产生信道失衡.为了提高网络传输均衡性和安全性,需要进行信道均衡调制处理,本文提出基于信道扩频的网络传输均衡调制算法,构建超高频网络通信信道模型,利用相邻的两组训练码进行信道参数测量,提取网络传输信道传输信号的谱特征量,采用前馈滤波器完成匹配滤波,根据谱特征偏移进行信道畸变补偿,采用最大比合并分集判决反馈调节方法进行网络传输均衡调制,计算信道的冲激响应,以此作为补偿系数进行信道畸变补偿,构建分集判决反馈均衡器实现网络传输信道补偿和自适应均衡调制.仿真结果表明,采用该方法进行分布式网络传输的信道均衡性较好,抗干扰能力较强,输出误码较低,实现了网络安全优化传输. 相似文献
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军用无线电通信对通信质量和码元的保真性要求较高,军用无线电通信信道受到多径向量的影响产生码间干扰,需要进行码间干扰抑制,降低通信误码率。传统的码间干扰抑制方法采用波特间隔信道均衡算法,当通信信道受到电磁扰动的强度较大时,信道均衡性和码间干扰抑制能力不好。提出一种基于时间反转镜技术的军用无线电通信的码间干扰抑制算法,首先构建了军用无线电通信的信道模型,进行军用无线电通信的信道多径特性测量,采用自适应级联滤波器进行干扰滤波,结合时间反转镜技术实现码间干扰抑制算法改进。仿真结果表明,采用该算法进行军用无线电通信的码间干扰抑制,能有效提高通信传输的保真率,信道均衡性能较好,提高了通信输出的信噪比,降低通信误码率,提高了通信质量。 相似文献
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非理想信道多用户数字信号的盲分离 总被引:3,自引:1,他引:2
在一个信道上传送多个用户信号,可以大大提高信道的容量,本文讨论了非理想信道多和户数字信号的盲分离问题,利用天线阵,接收可以看作是由N个独立信号源激励的非线传输混合系统的输出;由于信道存在的码间干扰,混合矩阵的元素不是常数,而是一个线性子系统,针对这一情况,本文提出了一个盲分离器结构,首先将接收信号进行盲分离,然后利用基于AR模型的盲均衡器消除每一路输出信号的码间干扰,从而实现多用户信号物分离,语文 相似文献
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传统雷达一般采用固定的发射波形,在干扰环境下很难获得最优的目标检测性能。针对这一问题,利用集中式多输入多输出(MIMO)雷达波形分集的优势,提出了一种干扰环境下的MIMO雷达波形与接收滤波联合优化算法。以最大化输出信干噪比为准则,使发射波形满足恒模条件,同时施加波形与具备较好脉压特性雷达波形之间的相似性约束,建立了有限相位发射波形与接收滤波权值的优化模型。然后,在循环迭代的算法框架下,将优化问题分解为2个子优化问题,并分别采用拉格朗日乘子法、半正定松弛技术对子优化问题求解,得到发射波形与接收滤波权值的联合优化结果。仿真结果表明,所提算法较现有方法相比有更高的输出信干噪比,使干扰信号的抑制性能得到改善,同时可兼顾发射波形的脉冲压缩特性。 相似文献
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Multisim 2001在基于UAF42陷波器设计中的应用 总被引:1,自引:0,他引:1
目前地球物理勘探(物探)工作使用的专业电子仪器的工作频率都较低,所以在物探仪器中运用陷波器相当普遍,特别是用于压制50 Hz电力线的干扰方面.为了压制50 Hz的工频干扰,要在仪器的信号调理部分采用陷波器电路.为了设计和优化基于UAF42的新型陷波器电路,采用Multisim 2001进行仿真实验.Multisim 2001借助虚拟现实技术,使设计者能快速地模拟、分析、验证所设计电路的性能.与传统方法相比,这种虚拟技术既省时又经济,而且还可避免实验中发生的各种损坏和事故.本文利用基于UAF42设计的50Hz陷波器的仿真电路,对陷波器的频率响应进行了仿真.仿真结果表明,基于UAF42的50 Hz陷波器达到了设计目的和要求,并证明了Multisim 2001在电路设计中的重要作用. 相似文献
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一种新型的扩频通信自适应窄带干扰抑制技术 总被引:3,自引:0,他引:3
提出了1种基于IIR带阻滤波器的窄带干扰抑制方式,不但能够对窄带干扰进行精确的频率跟踪,而且能够根据信号电平自适应设置干扰的检测门限,并通过选择最佳的滤波器参数滤除干扰,从而可以将干扰造成的性能损失减小到最低程度,计算机仿真证实了本方法具有良好的窄带干扰抑制效果和较低的实现复杂度。 相似文献
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邸珩烨 《智能计算机与应用》2016,(2):100-103
无线电扩频通信受到多径分量噪声的干扰,导致通信信道均衡性不好,抗干扰能力不强,误码率较高。需要进行噪声干扰抑制,改善无线电扩频通信质量。提出一种基于自适应级联陷波和码间干扰抑制的无线电扩频通信优化技术。构建无线电扩频通信系统传输结构模型,采用自适应陷波器对无线电扩频通信中的多径分量噪声进行有效抑制,降低了进入信号通频带内的干扰功率,提高解调器的输出信噪比和信干比。采用扩展后的序列去调制载波,将信号搬移到载频上,实现信道均衡,提高抗干扰能力。仿真结果表明,该算法能有效降低无线电扩频通信的误比特率,抗干扰性较强,提高通信质量。 相似文献
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间歇采样转发干扰(ISRJ)是基于欠采样原理的新型雷达相干干扰技术,能够形成密集假目标干扰。该文针对抗间歇采样转发干扰问题,提出一种雷达发射波形和非匹配滤波联合设计的抗干扰方法。首先,以发射信号脉冲压缩积分旁瓣能量和干扰信号非匹配滤波输出积分能量为目标函数,综合考虑发射信号的幅度约束,建立了间歇采样转发干扰抑制的数学优化模型。然后,通过问题分解推导了雷达发射波形和非匹配滤波器的解析表达式,基于迭代算法设计了发射波形和非匹配滤波器。最后,通过仿真实验的方式验证了发射波形和非匹配滤波器的性能、抗间歇采样转发干扰性能以及所提方法的间歇采样转发干扰抑制能力。 相似文献
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The application of the minimum-mean-square-error (MMSE) multiuser detection technique to the problem of suppressing the digital narrowband interference (NBI) from spread-spectrum signals is considered. The MMSE multiuser detector can be implemented using a blind adaptive method, which is ideally suited for use in the NBI suppression framework. The optimal linear filter for the recovery of the spread-spectrum signal is derived, and its performance is analyzed in terms of probability of error and signal-to-interference ratio (SIR). It is shown that the performance of this optimal filter is very close to the situation when there is no narrowband interference present, even at the presense of very strong interference. This application requires the treatment of a single narrowband digital signal as a group of related, virtual spread-spectrum signals with very simple spreading codes. This model gives a special structure to the matrices appearing in the optimization problem implied by the MMSE criterion, and this structure is exploited herein to develop and analyze a practical adaptive algorithm. The major contribution of this paper beyond the previous work in the field of NBI suppression is the development of this adaptive algorithm that can exploit the advantages of multiuser detection in suppressing narrowband digital interference from spread-spectrum networks. 相似文献
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Yu F. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1971,17(5):524-529
Generally, the synthesis of coherent spatial filters is restricted to the linear region of the transfer characteristic of a photographic film. However, a technique of synthesizing a nonlinear spatial filter such that the signal detection may be optimum will be described. In this paper, a generalized linear optimization technique is formulated. The application of this optimization technique toward a simple nonlinear spatial filter is demonstrated, and the extension of this optimization technique for a more complicated nonlinear spatial filter is also given. The signal detection by nonlinear optimum spatial filtering is analyzed. Finally, it is concluded that, instead of restricting the spatial-filter recording to the linear region of the transfer characteristic of the photographic film, an optimum nonlinear spatial filter may be achieved. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》1968,14(5):734-743
This paper considers the joint optimization of a class of radar signals and filters in a number of clutter-pins-noise environments. The radar signal processor in this case will be optimum in the sense that its output at the time of target detection yields the maximum ratio of peak signal power to total interference power. If the interference at the input to this signal processor is a Gaussian random process, this processor also yields the maximum probability of detection for a given value of false-alarm probability. The signals used are pulse trains and the filters are tapped delay lines. The purpose of signal design is to determine the optimum complex weighting for each pulse of the pulse train. Filter design yields the optimum complex weighting for the output taps of the delay line. Filter design for a specified signal is considered first. This is followed by combined signal and filter design and matched filter design. Constrained signal and filter design is investigated last. It should be emphasized that the optimizations require a knowledge of the clutter time-frequency distribution. For practical situations, when the clutter distribution is unknown, an adaptive filter is proposed that automatically provides the optimum filter weights for a given transmitted signal. When the clutter has a range-time extent less than the equivalent range-time extent of the signal, filter design alone yields nearly optimum performance. As the clutter becomes extended in range-time, it is necessary to consider jointly the design of signal and filter to obtain an optimum radar signal processor. In this report it is suggested that the signal be designed under the assumption of the clutter being extended over a broad range of Dopplers and that the signal processor consist of a bank of adaptive filters. Then each filter output yields the maximum ratio of peak signal to total interference power for this signal design. 相似文献