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自适应阵列智能天线抗干扰性能研究 总被引:3,自引:1,他引:3
分析了自适应阵列智能天线的基本原理,给出了基于复数LMS算法的自适应阵列智能天线波束形成方法,同时对该智能天线抗干扰性能进行了Matlab仿真,理论分析和仿真结果表明:自适应阵列智能天线阵能够实时地调整天线方向,使天线的主波束对准期望信号方向,零陷对准干扰方向从而抑制干扰信号,在干扰和低信噪比环境下,接收端使用智能天线可以大大降低误码率,该智能天线具有较强的抗干扰性能。 相似文献
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基于混沌粒子群算法的阵列天线容差分析 总被引:1,自引:0,他引:1
研究阵列天线性能优化设计,针对阵列天线幅相误差对天线性能的影响,传统的阵列天线容差分析采用统计理论方法,前提需要假设幅相误差服从某种概率分布,导致不同分布的幅相误差对应不同的结论形式,并且公式推导过程复杂.为了在建立阵列天线最坏情况容差分析的数学模型,提出了一种混沌粒子群算法简单实用的阵列天线最坏情况容差分析方法.通过在粒子群算法中利用混沌技术优化初始种群,并对位置更新时引入混沌扰动项和位置更新后进行边界约束,进行仿真,提高了粒子群算法的全局搜索能力.结果验证了算法在最坏情况分析时,可以得到在准确性和稳定性方面的优化结果. 相似文献
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为了加快天线建模速度,针对现有天线设计软件天线参数优化速度过慢问题进行了建模研究。首先通过几种常用的启发式算法优化后的多层前馈(Back propagation,BP)神经网络对天线参数进行优化比较,并对其中最优的算法遗传算法优化BP(Genetic algorithm BP,GABP)神经网络算法进行深度改进。其次采用自适应算法和模拟退火算法优化算法对GABP进行优化。最终通过模拟试验验证出自适应GABP算法对于天线参数优化的误差最小。该研究为天线设计软件中天线优化方法提供了一种误差较小的新方法,拥有更高的预测准确度,拟合速度也大大提升。实验对比证明了该算法的可行性。 相似文献
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首先介绍了智能天线的基本概念和分类,随后着重介绍了三种自适应算法。继而描述了将智能天线用于车载高清晰数字电视的研究,最后提出了智能天线有待研究的课题。 相似文献
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随着通信等行业的发展,对自适应阵列天线滤波系统的吞吐量提出了更高的要求。本文利用压缩感知技术的稀疏化特点降低数据的计算复杂度。首先减少天线阵元所接收信号的测量数据,再送至自适应天线系统进行滤波处理,然后通过重构算法——SP算法(子空间匹配追踪)进行信号重构,能有效地降低自适应阵列天线滤波系统的计算复杂度,提高自适应阵列天线滤波系统的数据吞吐量。 相似文献
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针对载波偏移引起OFDM系统的严重子载波干扰和性能下降这一问题,提出一种在承载数据子载波中间插入不承载数据的子载波的算法,算法是通过从时域OFDM符号的前半部分和后半部分的相位差获取频率偏移的信息来估计频偏的。这种算法不仅计算复杂度较低,而且估计准确,在多径信道条件下频偏校正后系统的性能能基本接近信道理想估计条件下的误比特率。 相似文献
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In this article, details of a dual band microstrip patch antenna (MPA) array feed for an offset reflector antenna is presented. The main objective of the proposed structure is to achieve low cross‐polarization at Φ = 90° plane in the reflector pattern. Low cross‐polar levels in the reflector pattern are achieved by illuminating the reflector with fields of the proposed dual band feed structure. A centered circular array as the dual band feed structure is proposed in which the central radiating element is a dual mode circular MPA operating at 6 GHz and the surrounding circular ring of eight circular MPA elements operating at 4 GHz in the dominant mode. The dual mode central antenna uses the concept of conjugate field matching for cross‐polarization reduction. TM21 mode is excited at an appropriate ratio with the TM11 mode to achieve the proper field matching at 6 GHz. The radius of the surrounding circular array is varied to obtain cross‐polarization better than ?30 dB at both the resonant frequencies. The offset reflector gain is found to be better than 37 dB with a 2.5 m parabolic reflector and F/D = 0.8 at both the operating frequencies. 相似文献
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This article outlines impact of various factors on cross‐polarization characteristics of offset reflector antenna for communication spacecraft with smaller sized bus at C band. Effects of different parameters are considered in rigorous analysis of the antenna. Measured and predicted performances are found in agreement. To fulfill specific requirement of higher edge‐of‐coverage gain (>26 dBi) and higher cross‐polarization discrimination (XPD > 30 dB) over a wider coverage and dual linear polarization under the imposed constraints, a novel trimmed‐reflector offset parabolic antenna (TROPA) is devised. This interesting configuration is obtained by trimming both sides parallel to symmetrical plane of a parabolic offset reflector antenna. Parametric study of trimming distance versus its impact on cross‐polarization is also presented. The TROPA acquires wider bandwidth, simplification in its mechanical design and manufacturing, and offers low weight and compactness. It is also shown that trimmed reflector has almost even RF performance in presence of spacecraft body and other antenna. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012. 相似文献
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针对多带OFDM超宽带(MB-OFDM UWB)系统,依据物理层国际标准ECMA-368,对现有的频偏估计方法做了改进,提出了一种高性能、低复杂度、高鲁棒性的联合载波和采样频偏估计方法。该方法在SC算法基础上,通过选择合适的相关距离,使频偏估计算法适合于所有的跳频模式,同时也改善了估计性能。仿真结果表明,新方法在保证估计性能的基础上可有效降低复杂度,适合于高速MB-OFDM UWB系统。 相似文献
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基于对3G通信网络中阵列天线通道不一致性校正算法的性能分析,提出了一种基于参考信号源的自适应阵列天线通道不一致性校正算法。该算法充分利用了B.Friedlander算法和注入参考信号的校正方法的优点,通过使用参考信号的到达角估计值信息,来自适应地校正阵列天线中各阵元参数的不一致性,这些参数包括增益、幅度和相位因子。计算机仿真实验表明,推荐的算法大大改善了MUSIC算法估计来波信号方向的准确性,其性能远远超过了已有的各种校正算法。 相似文献
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This article presents a versatile pattern synthesis algorithm for controlling the sidelobe level and nulling region for circular antenna arrays. Nonuniform fast Fourier transform using the min–max interpolation method is utilized to overcome the nonlinear feature of circular arrays. The major advantage of the proposed algorithm is low complexity, which is key for hardware implementation. Moreover, the proposed algorithm functions well in amplitude‐only pattern synthesis, which may be required for low‐cost array systems using attenuators instead of complete amplitude and phase adjustment modules. Additionally, element failure of antenna arrays can be minimized in practical operations by resynthesizing the pattern by using the remaining antennas to achieve satisfactory performance. Simulation results indicate the lower complexity and higher versatility of the proposed algorithm compared with the conventional methods. 相似文献
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Satyajit Chakrabarti 《国际射频与微波计算机辅助工程杂志》2018,28(6)
In this study, we present a new technique for the development of a dual frequency microstrip antenna. Two identical polarizations at two far apart frequencies have been generated in a compact configuration which uses two elements fed by a single feed line. This design technique provides an independent control to the desired frequencies and reduces element size by 50% compared to the conventional design at the cost of a marginal decrease in gain. The proposed antenna produces dual resonances at 4.056 and 4.96 GHz. It yields impedance bandwidths of about 1.71% at the lower resonance and 1.41% at the higher resonance respectively. It exhibits 7.0 and 6.6 dBi gains at the lower and upper resonances respectively which are 0.3 and 0.7 dB lower than a conventional patch. The measured cross polar discriminations of the proposed antenna are also comparable to the conventional patch. The measured efficiencies are 81.3% and 78.1% respectively. 相似文献