子阵列

A novel direction of arrival and polarization estimation of electromagnetic vector sensors mounted on the airframe is proposed based on biquaternion. The signal processing model for EM-sensor mounted on the airframe is made by biquaternion and then the eigenvalue decomposition of spectral matrix is obtained by means of the EVD of its quaternion adjoint matrix. The memory requirement for data is reduced, and more accurate estimation result is gotten by deducing the stronger orthogonality constraint between the sin- gal and noise subspaces on the field of biquaternion. The performance of the new algorithm is confirmed through numerical examples.

针对机载电磁矢量传感器阵列DOA和极化参数估计问题，提出了一种基于复四元数估计方法，该算法利用四元数建立机载电磁矢量传感器阵列信号处理模型，然后利用四元数联合矩阵的特征分解得到阵列数据相关矩阵的特征分解，一方面使得计算过程中数据的贮存量大大减少，另一方面通过推导得到信号子空间和噪声子空间在四元数域上的正交性从而使DOA和极化参数佑计的精度更高，仿真证实了本算法的有效性。

This will be important for the research and practice of antenna arrays.

其结果对偶极子阵列的研究和实践有较大的意义。

Based on the depth research on extension array manifold of uniform circular, for some uniform circular arrays which had subarrays with the nature of rotational invariance and had the nature of central symmetry two ESPRIT algo-rithms were presented, the first algorithm reduced one time of SVD, the second algorithm avoided parameter pairs.

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。

On the basis of array model of the Multiple-Input Multiple-Output radar, a universal array model of the Synthetic Impulse and Aperture Radar is constructed and a realization sheme for microwave SIAR with a thinned subarray set for the transmitted array and a dense subarray set for the received array is proposed.

结合MIMO雷达多发多收的特点，建立了微波综合脉冲孔径雷达的阵列模型，并提出该阵列的一种实现方案：发射阵采用稀布子阵集，接收阵采用密布子阵的形式。

In this dissertation, what under consideration is the dipole array.

本论文中考虑的都是偶极子阵列，但是对其他型式的单元组成的天线阵的口面分布的实现，本论文的基本思想也有一定的指导作用。

By time-varying filtering, we realize the signal selectivity and interference suppression, especially for the signals with time-varying power spectrum. It is shown herein that conventional eigenstructure based methods are lower dimensional special case of the time-frequency subspace fitting method. The closed-form array response estimation algorithms for blind source separation in wireless communication is also developed in the dissertation by exploiting the data structure of second-order statistics of the array output in the presence of multipath. The proposed method achieves array response estimation with little constraint on signal property and propagation environment such as scatters or angular spread. Moreover, the array utilized here can be of arbitrary geometry and even uncalibrated. Since the closed-form solution is obtained, no misconvergency may occur and large amount of computation can be saved. The equivalent feed model and corresponding optimization designation are proposed to realize the downlink multi-user selective transmission. By coherent and non-coherent superposition of the electromagnetical field, multiple beams can be formed using a single array, so that each co-channel user signal is transmitted in each beam and will not interfered with each other. The proposed system scheme implements the digital beamforming and the channel allocation in the base band, therefore is suitable for the utilization of the radio software technology. The feasibility and effectiveness of the proposed model are proved by the RF experiment.

在窄带条件下，GSC－SSF方法还可以提高阵列的虚拟孔径，从而提高估计的性能；可以证明，Cyclic DOA 和SC-SSF方法可看作该方法的特例或近似； 3、提出了二维GSC－SSF方法和宽带谱相关DOA矩阵方法，利用信号的循环平稳特性解决了宽带条件下二维 DOA 估计问题，并具有阵元数少、计算量较小的特点； 4、提出了时频子空间拟合和宽带时频DOA估计算法，将联合时频分析的理论和方法引入到阵列信号的空间谱估计研究中，利用时变滤波实现信号选择性测向和干扰抑制，特别适合于谱时变信号；可以证明传统特征结构法可看作是时频子空间拟合方法的特例； 5、提出了多用户环境下阵列响应的估计方法——CARE方法，该方法对信号结构和传播参数（主要是散射源分布与角度散布）的约束较少，适用于各种几何结构的阵列甚至未校准的阵列，能够直接得到阵列响应的闭式解，因此计算量小、稳健性好，不存在收敛问题； 6、提出了针对多用户下行选择性发送的阵列等效激励模型、优化设计方法及其系统实现方案，通过空间场的相干叠加与非相干叠加使得单一阵列能够形成多个波束，并保证各波束内的用户信号各不相同且相互干扰最小；其系统方案具有在基带实现数字波束成形、信道分配并便于软件无线电实现的特点，其有效性已得到外场实测数据的证实。

A kind of downhole multipole acoustic transducer transmitter with high power that is applied to petroleum tools was introduced.

介绍了一种用于石油仪器的大功率多极子阵列声波换能器激励源的设计方案。

An electronic circuit for multipole array acoustic logging receiver was designed for petroleum tools.

设计了一种用于石油仪器的多极子阵列声波接收电路。

Analysing the information strcture of the cross diploes, a DOA and polarization estimation method is presented for broadband signals.

研究了正交偶极子阵列的信息构成，提出基于该阵列的宽频段信号DOA与极化联合估计算法。

Microwave absorbing properties of the composites containing activated carbon-fiber felt dipole array s were investigated.

研究了含活性碳毡对称振子阵列吸波复合材料的微波吸收特性。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。