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阵列天线方向图综合作为智能天线的一项重要技术对于复杂系统的优化问题提出了更高的要求.本文结合差分进化的基本思想和遗传算法的基因交叉和变异方法构建了一种新的混合优化方法.该算法使用差分进化算子作为主要优化手段,结合遗传算法优胜劣汰的基本思想以及其中的交叉和变异方法,通过融合两种优化方法各自的优点,可以显著改善多参数、高度非线性问题的优化结果、提高计算效率.计算机仿真结果表明,与现有算法相比,该算法用于天线方向图综合具有收敛速度快、优化能力强、算法可靠等优势. 相似文献
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自适应阵列天线常需要采用宽零陷技术,以增强阵列天线抗干扰的稳健性。为此,提出了一种基于混沌粒子群算法(CPSO)的阵列天线宽零陷方向图综合方法。该算法首先采用混沌序列初始化粒子位置,以增强搜索多样性,并在对部分非优胜粒子的位置更新时引入混沌扰动项,在每次迭代中对全局最优位置进行变尺度混沌优化,提高了全局和局部搜索能力,加快了收敛速度。仿真结果验证了混沌粒子群算法在阵列天线宽零陷方向图综合时的收敛速度和精度方面均优于标准粒子群算法。 相似文献
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研究正交MIMO雷达在给定发射、接收天线孔径长度和阵元数目固定等约束条件下的天线方向图综合问题.MIMO雷达采用稀布天线,为了克服栅瓣效应并且降低旁瓣电平,同时为了避免遗传算法早熟收敛,进入局部最优,提出了一种与模拟退火算法相结合的多重混合遗传布阵优化方法.该方法为了保证系统最大自由度,引入了距离扰动,同时对发射天线和接收天线的位置进行优化,有效解决了MIMO雷达天线方向图综合中低旁瓣电平设计问题.仿真结果证明了所提算法的有效性和优越性. 相似文献
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传统阵列方向图宽零陷形成技术需要对阵元施加复加权或者阵元位置扰动等复杂操作,实际实现比较困难。提出了一种基于遗传算法的唯相位波束赋形方法,针对宽零陷特点,结合均匀线阵方向图数学模型,设计一种适应度函数,优化阵元相位扰动值,最终获得符合要求的宽零陷阵列方向图。仿真结果表明,该方法可以在唯相位条件下形成较深的宽零陷,且零陷较平坦,收敛速度较快,稳健性较好。 相似文献
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提出了一种基于本征激励方向图综合的改进实数编码遗传算法.在遗传算法选择算子中引进分裂选择机制,较好地开发了解空间;交叉算子采用了基因交换、中间重组、算术交叉形成综合‘交叉方式,对解的开发深度明显优于单一的传统算术交叉;对变异概率采用渐变控制,有效地扩大了搜索空间,克服了传统算法早熟的现象,良好的搜索结果证明了算法的精确性.算法基于本征方向图综合思想,由于实测本征方向图包涵了互耦信息,有效地解决了阵列天线互耦问题,避免了阵列互耦校正的复杂过程,具有较大的实用价值. 相似文献
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为消除特定方向的干扰,天线阵列零点生成成为信号处理的关键技术.本文将重要度采样策略的交叉熵算法应用到唯相位控制的天线阵列方向图零点生成.该算法每次迭代的候选样本来源于参数化概率密度分布,保证了样本的多样性,使样本集更加趋近最优结果.有效的克服了早熟现象,计算速度较快.仿真结果表明,该算法在方向图的主瓣附近、旁瓣区、对称主瓣两侧都能生成零点,零点生成范围较大.零功率宽度为120,最大副瓣电平为-12dB时,平均零陷深度达-190.12dB,是免疫算法的3倍. 相似文献
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Lahcene Hadj Abderrahmane Belgacem Boussouar 《AEUE-International Journal of Electronics and Communications》2012,66(9):752-757
Deterministic techniques have been extensively employed in antenna array synthesis, using physical parameters of the array to determine an optimal solution. These deterministic algorithms, requiring good initial conditions, can become unstable and require long convergence times. In contrast, optimisation methods using stochastic principles have become popular techniques for solving the synthesis problem. The cross entropy (CE) method is one of those more popular algorithms, such as genetic algorithm (GA) and particle swarm optimisation (PSO), possessing good convergence properties. Then, the CE method is a global stochastic optimisation technique for solving both continuous and discrete systems.This paper describes the planar antenna arrays synthesis using the CE method to produce array responses with minimum peak sidelobe levels (SLL).Good simulation results are obtained with SLL of ?22.7 dB for isotropic elements and ?32.17 dB for non-isotropic elements. By comparison to more popular algorithms, the CE method can optimise a large number of discrete parameters in a short time but GA requires a long time (large iteration number) to achieve the same performance. 相似文献
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针对阵列天线中阵列孔径、阵元数目、阵元间距等多约束的稀布线阵综合问题,文中提出了一种基于改
进麻雀搜索算法的稀布阵列综合优化方法。给出了改进麻雀搜索算法的流程,并在确定阵列孔径、阵元数目和最小阵
元间距的约束条件下,采用Tent 混沌映射进行天线阵元位置的初始化,提高算法的搜索性和收敛性,实现了抑制天线
峰值旁瓣电平(PSLL)的稀布线阵综合仿真。仿真结果表明,所提出的方法相比于其它文献中的优化方法,能够得到更
低的峰值旁瓣电平,稳健性好,效率高。在仿真结果的基础上,引入实际天线进行组阵分析,验证了该方法的可行性。 相似文献
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Ertugrul Aksoy Erkan Afacan 《AEUE-International Journal of Electronics and Communications》2009,63(2):116-122
Differential evolution algorithm is used for the pattern synthesis of planar antenna arrays with prescribed pattern nulls by position-only and position-amplitude optimization. The position-only optimization for a planar array allows null synthesis in any prescribed direction. For planar antenna array thinning it is necessary to use position-amplitude optimization for problems involving more than two nulls. 相似文献
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最小均方(LMS)算法是自适应阵列天线中得以广泛应用的阵列天线加权算法。提出了一种基于遗传优化的LMS改进算法,该基于遗传优化的最小均方(GA—LMS)算法充分结合了遗传算法的并行处理和全局搜索的优点。实验结果表明,与传统的LMS算法相比,GA—LMS算法具有良好的收敛性能,并可更好地抑制干扰信号,有效改善自适应阵列天... 相似文献
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基于边缘吸引力场正则化的短程线主动轮廓模型 总被引:11,自引:1,他引:10
短程线主动轮廓模型是近几年提出的一种有效的多目标轮廓提取算法.本文在详细分析其动力学过程的基础上,针对该模型中存在的局限性和不足,提出对边缘吸引力场进行正则化的方法,并采用多尺度模型,有效的改善了该模型不能对存在断裂轮廓的目标进行正确提取和凹边缘搜索能力弱的缺点,增强了抗噪声和虚假边缘干扰的能力,使该算法具有更好的鲁棒性和实用性. 相似文献
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It is well known that a linear antenna array with equally spaced elements can be represented by a polynomial whose roots correspond to the nulls of its antenna pattern. Since the linear array has equally spaced elements, its polynomial has only integral powers of the variable, so that the array can be represented by aZ transform. Therefore, the effect of moving roots of the polynomial can be represented as a linear sampled-data system problem, which is solved by using a table ofZ transforms or by discrete numerical convolution. In this paper, the quantitative effects on the array and its antenna pattern caused by moving roots of the polynomial are determined, and these effects are utilized for array synthesis to produce desired antenna patterns. Examples illustrating the use of this new synthesis technique include modification of a uniform array to obtain low sidelobes in the antenna pattern and synthesis of an array to produce nulls in its antenna pattern in the directions of discrete and spatially distributed interference sources. 相似文献
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In this paper, based on the phase-position perturbation method, an
innovative optimal adaptive antenna technique is proposed, where the
deduced radiation pattern formulas available for searching optimal
solutions are used to search the optimal weighting vector. The
optimal radiation pattern designs of adaptive antenna are studied by
the phase-position perturbation method. Memetic algorithms are used to
search the optimal weighting vector of the phase-position
perturbations for the array factor. The design for an optimal
radiation pattern of an adaptive antenna can not only adjustably
suppress the interferers by placing nulls at the directions of the
interfering sources, but at the same time provide a maximum main
lobe in the direction of the desired signal, i.e., to maximize the
signal-to-interference ratio. To achieve this goal, a
new convergent method, referred to as the two-way convergent method
for memetic algorithms, is proposed. The memetic algorithm combines
a genetic algorithm and local search heuristics to solve combinatorial
optimization problems. The memetic algorithm is a kind of improved
type of the traditional genetic algorithm. By using a local search
procedure, it can avoid the shortcomings of the traditional genetic
algorithm, whose termination criteria are set up by using the trial
and error method. This proposed method is also able to solve the
multipath problem, which exists at the same time in this
communication system. The optimal radiation pattern concept can be
implemented in practical wireless communication systems. Simulation
results are also given in this paper. 相似文献
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该文针对LEO星载阵列天线抑制角度动态变化的有源干扰的需要,提出一种干扰子空间正交投影的快速零陷跟踪波束赋形优化算法。算法采用干扰子空间动态更新与迭代正交投影,不断快速修正零陷位置,并通过迭代傅里叶变换(IFT)技术进行优化加速。所提出的快速算法在整个干扰零陷跟踪过程中,具有稳健和精确的控制方向图主瓣赋形区形状和阵元电流激励系数动态范围的能力,同时具备自适应最小化方向图旁瓣电平的能力,适用于星载系统在线实时计算。仿真实验验证了算法的快速性、有效性和稳健性。 相似文献