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针对均匀圆阵互耦自校正问题,提出了一种基于旋转不变参数估计(ES-PRIT)技术的互耦自校正算法。通过模式空间转换技术将互耦影响下的均匀圆阵流型向量近似等效为存在幅相误差的虚拟均匀线阵流型向量,并且该幅相误差矩阵满足中心对称性。利用该性质并结合ESPRIT技术分别给出了信源方位和互耦向量的闭式解。为了减少模式空间转换偏差的影响,基于Belloni方法,给出了一种互耦影响下抵消模式空间转换偏差的方法。仿真实验验证了新算法的有效性。 相似文献
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本文提出了一种适用于无效圆阵的相干信泊空间谱估计的方法,它利用空间预处理技术,交阵元空间的均匀圆阵变换成相位模式空间内的虚拟均匀线阵,通过将均匀线阵的窨平滑技术和增强平滑技术应用于该虚拟阵,可获得文中的模式平滑算法,该算法仅利用一维挝不可使均匀四具有检测相干信源的能力,避免了圆阵看成 一般平面阵时所必须的多维搜索,减少了计算量,计算机模拟结果了算法的正确性和有效性。 相似文献
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该文用均匀线阵研究了未知接收机通道特性下信号“空间特征”“w=2π△sinθ/λ)的估计问题,利用均匀线阵的冗余结构,本文给出了基于信号子空间的ESPRIT-Like算法,得到了一个信号“空间特征”和通道特性的近似解,ESPRIT-Like算法对信号“空间特征”估计具有较好的稳健性;与B.Friedlander,V.C.Soon等人(1994)提出的其它迭代算法相比,ESPRIT-Like算法具有计算量小的优点,数值仿真结果证实了本文算法的有效性并评价了算法的性能。 相似文献
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在深入研究均匀圆阵扩展阵列流形的基础上,针对某些均匀圆阵的扩展阵列中含有旋转不变性的子阵列组以及中心对称性质,提出了2种基于均匀圆阵的二维ESPRIT算法,第一种算法减少了一次奇异值分解,第二种算法避免了参数配对。仿真结果验证了算法的正确性和有效性,并且在高斯色噪声条件下,其测向性能均优于MUSIC算法和最大似然算法。 相似文献
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传统的基于原子范数最小化(Atomic Norm Minimization, ANM)的波达方向(Direction of Arrival, DOA)估计算法无法直接应用于不满足范德蒙德结构的非均匀圆阵,针对这一问题提出了一种基于虚拟阵列变换的改进方法。以某非均匀圆阵作原始阵列为例,首先通过虚拟阵列变换处理原始阵列接收的数据,使其转换为虚拟的均匀L阵接收数据,将非均匀圆阵上的DOA估计问题转化为两个均匀线阵上的DOA估计问题,再利用基于ANM的DOA估计算法与L型阵的二维角度关系还原出方位角和俯仰角。通过仿真与实测实验验证了所提算法应用于非均匀圆阵的可行性,并分析其DOA估计结果,证明其拥有较高的估计精度。 相似文献
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Beamspace Transform for UCA: Error Analysis and Bias Reduction 总被引:4,自引:0,他引:4
《Signal Processing, IEEE Transactions on》2006,54(8):3078-3089
In this paper, we analyze the error caused by the beamspace transform (BT) when it is applied to uniform circular array (UCA) configuration. Several algorithms for direction of arrival (DoA) estimation exploit this modal transform because it allows using computationally efficient techniques such as polynomial rooting and dealing with coherent sources. The BT is based on the phase-mode excitation principle. The performance of such DoA estimators is degraded if the array has a small number of elements. We introduce a modified beamspace transform (MBT) that performs mapping from element-space to beamspace domain taking into account the error caused by the transform. Justification of the difference in the statistical performances of MUSIC and root-MUSIC algorithms for UCA is also given. Moreover, we show that there is a significant difference in the performance of the UCA root-MUSIC technique depending on whether an even or odd number of elements is used. We derive an expression approximating the bias in the DoA estimates that is caused by the beamspace transform. Some design guidelines are provided for choosing the key UCA configuration parameters such as number of sensors, array radius, and interelement spacing in order to reduce the error. Finally, we propose a novel technique for bias removal. It allows practically bias-free DoA estimation. 相似文献
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Chunqi Chang Sze Fong Yau Paul Kwok Francis H. Y. Chan F. K. Lam 《Circuits, Systems, and Signal Processing》1999,18(3):225-239
The uncorrelated component analysis (UCA) of a stationary random vector process consists of searching for a linear transformation that minimizes the temporal correlation between its components. Through a general analysis we show that under practically reasonable and mild conditions UCA is a solution for blind source separation. The theorems proposed in this paper for UCA provide useful insights for developing practical algorithms. UCA explores the temporal information of the signals, whereas independent component analysis (ICA) explores the spatial information; thus UCA can be applied for source separation in some cases where ICA cannot. For blind source separation, combining ICA and UCA may give improved performance because more information can be utilized. The concept of single UCA (SUCA) is also proposed, which leads to sequential source separation.This work was supported in part by grants from the Research Grants Council of Hong Kong, grants HKU553/96M, HKU7036/97E, and HKUST776/96E. 相似文献
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A combined random/reservation multiple access (CRRMA) scheme for packet-switched communication over a global beam satellite with on-board processing is proposed and analyzed. Channel time is divided into contiguous slots; each slot containsN minislots for transmission of request packets andN' minislots for data. WithN substantially smaller than the number of earth stations, collisions will occur in request packet transmissions. Two channel access algorithms for the CRRMA model are proposed: uncontrolled channel access (UCA) and controlled channel access (CCA). UCA is simpler but has an inherent stability problem particularly when the number of minislotsN is small. The CCA algorithm restricts the transmission of request packets for new arrivals to take place only when the slot is in the FREE state. WithN = 3 , the CCA algorithm exhibits good delay-throughput characteristics. AsN increases, the UCA algorithm offers stable operation. ForN geq 5 the simpler UCA algorithm is preferred over CCA. 相似文献
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均匀圆阵(UCA)是一种应用广泛的具有二位波达角估计能力的平面阵列。为了从理论上分析不同阵列参数下到达波方位角(AOA)、仰角估计精度,推导了均匀圆阵二维波达角估计的性能界,以此为基础分析了阵列孔径、阵元个数、快拍数以及来波仰角高低与到达角估计精度的关系,并通过对UCA-MUSIC算法计算机仿真验证了推导结果的正确性。研究结果为波达角估计类算法提供了可供参考的性能下界,圆阵设计时也不再需要大量的Monte Carlo仿真试验确定阵列参数,可直接从估计精度表达式中获得。 相似文献
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该文研究了环形天线阵列生成具有轨道角动量的微波频段涡旋电磁波的过程中,天线阵列单元间的耦合对生成的涡旋电磁波的模式的影响.通过理论分析,以及基于矩量法的全波电磁数值计算,给出了在一定的条件下,耦合对生成的涡旋电磁波的模式数的影响.结果表明,当存在耦合的旋转对称性时,耦合不会对涡旋波的生成造成影响;而当不存在耦合的旋转对称性时,单元间耦合会使生成的涡旋波偏离理想结果.耦合对涡旋波的影响程度敏感于模式数、环形阵列半径、观测点方位.基于文中的参数,即使相邻单元间距大于两个波长,耦合也可能使模式数改变14%以上. 相似文献