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T. S. Ghouse Basha P. V. Sridevi M. N. Giri Prasad 《Wireless Personal Communications》2013,71(2):1353-1364
Smart antenna is now commonly used in communication systems due to its high advantages. In order to improve the performance of smart antenna operation, efficient design of beam forming pattern is required based on the subjected antenna parameters. In the previous works, beam forming techniques were proposed using hybridization of soft computing techniques, however the precision has not been considered in terms of direction of arrival (DOA). This paper includes DOA while deriving the beam forming pattern of smart antenna. To estimate precise DOA, the MUSIC algorithm is improved by introducing a tuned correlation matrix after solving the objective model for the matrix. Thus estimated DOA pattern is more precise as the unwanted side lobes are suppressed when compared to the conventional DOA pattern. Based on the estimated DOA pattern, the antenna beam forming pattern is derived as per the required direction of angles. The experimental results show the performance of the proposed beam forming technique over the previous techniques. 相似文献
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在即将商用的3G移动通信系统中,智能天线技术成为研究的热点.本文是以智能天线技术中DOA估计为基础,研究一种可提高估计能力的虚拟阵列DOA估计算法。介绍了虚拟阵列变换技术,根据智能天线系统的特点.采用空间分域的子阵思想.结合虚拟阵列变换技术.实现空间分域的虚拟阵列DOA估计。 相似文献
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智能天线的波束形成算法与实现 总被引:4,自引:4,他引:0
提出了一种基于遗传算法的波束形成方法。该方法具有很好的收敛性,与传统的LMS算法相比,遗传算法具有良好的全局搜索能力,对于复杂的搜索空间,能快速地找到最优解。利用FPGA进行空域滤波,通过DSP浮点运算,高效地实现权值估计,避免高位加法进位影响权值速度,使得智能天线波束形成算法的实现简便易行。 相似文献
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The concept of a preserving source orthogonality and characteristic beam is defined according to an array data model. It is proven theoretically that the corresponding eigenvectors maintain the preserving orthogonality when the powers and the angle intervals between the signals are large. The theory is then applied to the direction of arrival (DOA) estimation for the array antenna in the presence of strong interference. A novel DOA estimation algorithm based on the elimination of the eigenvectors of interference is proposed. The simulation results and comparison of the jamming jam method (JJM) algorithm show that the proposed algorithm does not require the position of the interference source to be known. Moreover, its interference suppression ability and statistical estimation performance are superior to those of the JJM, and thus, it is more suitable for low SNR and small angle intervals. 相似文献
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智能天线的核心技术之一是波达方向估计,在无线通信中具有重要作用。MUSIC算法是一种经典的DOA估计算法,但因其计算量大、对于相干及小信噪比信号无法分辨等缺陷,故有较多的改进算法被提出。文中研究了求根MUSIC算法、基于空间平滑技术的MUSIC算法、改进MUSIC算法及修正MUSIC算法。通过仿真分析了角度间隔、信噪比、信号相干对改进MUSIC算法分辨率的影响。以上几种改进MUSIC算法进一步发挥了该算法高分辨率的优势,且有利于其在智能天线方面的应用。 相似文献
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Shiann‐Shiun Jeng Hsin‐Piao Lin Chen‐Wan Tsung 《International Journal of Communication Systems》2003,16(3):211-223
This paper presents some preliminary results from experimental studies on space‐division‐multiple‐access (SDMA) for wireless communications. A smart antenna system utilizing direction‐of‐arrival (DOA)‐based beamforming techniques can enhance signal quality by reducing co‐channel interference from mobiles located at angles spatially distinct from the base station. Adopting both smart uplink and downlink beamforming, a communication system with an antenna array can increase the cell coverage of a base station and significantly boost capacity compared with conventional antenna systems. However, successful implementation of DOA‐based beamforming techniques depends on the DOA characteristics. This paper presented the feasibility of direction finding and DOA variation with respect to frequency. Furthermore, the angle spread was studied for selected environments. The results demonstrate the feasibility of applying proposed smart antenna system utilizing DOA‐based beamforming algorithm for increasing channel capacity and improving system performance in frequency‐division‐duplex (FDD) wireless communication systems. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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波达方向估计是智能天线的重要功能之一,对于相干信号角度模糊问题通常严重影响了方向判断的精准度.文中根据一维空间平滑基本理论和算法,对二维六边形阵列相干信号MUSIC算法波达方向估计问题进行了理论分析和仿真实验,提出了平面六边形阵列到十字形阵列的变换方法,成功地把一维平滑技术应用到平面六边形阵列,仿真表明,这种变换可以有效地消除相干信号的角度模糊问题. 相似文献
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R. Ghayoula A. Smida A. Gharsallah D. Grenier 《International Journal of Communication Systems》2014,27(12):3706-3719
This paper presents practical design of a smart antenna system based on direction‐of‐arrival estimation and Dolph–Chebyshev beam forming. Direction‐of‐arrival estimation is based on the multiple signal classification algorithm for identifying the directions of the source signals incident on the sensor array comprising the smart antenna system. The smart antenna system design involves a hardware part, which provides real data measurements of the incident signals received by the sensor array. This paper presents the Dolph–Chebyshev method for the synthesis and design of antenna arrays with periodic element spacing. A Field‐Programmable Gate Array implementation is presented for an antenna array application employing digital beamforming. The array comprises 10 elements, equal in number receiving radio frequency and intermediate frequency components, as well as a Spartan‐3E Field‐Programmable Gate Array‐based unit, which is responsible for the control of the array. Low‐cost and switched‐beam, and fully adaptive antenna array suitable for 2‐GHz applications are proposed in this paper. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Guo Li Guo Yan Li Ning 《电子科学学刊(英文版)》2007,24(3):406-411
A novel simply-structured hybrid smart antenna system suitable to be used in ad-hoc network terminals is proposed in this letter. The super-resolution beamforming algorithm is also presented based on the system using DOA estimation results. The algorithm can switch the bea.mforming to the direction of the expected signal and get the best transmitting performance after the pre-beamforming of the Butler matrix. The shifting value formulas are presented to obtain the best SNR when there is no interfering signal and to acquire the highest Signal to Interference Ratio (SIR) as there is one interfering signal. When there are more than one interfering signals, the pre-bea.mforming feature of the Butler matrix can also suppress the interfering signals. Simulation results verified the algorithm. 相似文献
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Numerous methods for direction of arrival (DOA) estimation, used in smart antennas have been already reported in previous studies. The precision of DOA estimation depends on the choice of the algorithm and the geometrical configuration of the antenna array. In this work, the performance of new geometrical configurations, i.e. 2D with equal area and 3D with equal volume including circular, square, triangular, hexagonal and star geometries, with equal number of antenna elements, are examined and compared to each other to find the most proper geometry. Monte-Carlo simulations are performed to evaluate the DOA precision of the proposed arrays using the MUSIC algorithm. It is shown that in three cases of comparison including 2D geometries, 3D geometries and 3D rotated geometries, with the star and triangular configurations one achieves better resolution in DOA estimation. It is also revealed that the rotated configurations show lower estimation error compared to normal configurations. 相似文献
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This paper deals with the problem of estimation of direction of arrivals (DOA) of a multiple ultra-wideband (UWB) pulse postion modulation signals incident on a smart antenna in the presence of white Gaussian noise. We transform the received signal into frequency domain in order to split the array output into multiple frequency channels. Corresponding frequency channels data of the array is arranged into a model similar to narrowband DOA estimation. Iterative quadratic maximum likelihood algorithm is applied to yield DOA estimates. These separate estimates at different frequencies are combined into a single estimate of DOA for each source in an appropriate manner. The performance of the proposed method is studied via extensive computer simulations. It is seen that the technique can successfully resolve the DOA of the closely-spaced UWB signals. 相似文献
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分析了智能天线阵列的工作原理,在智能天线实验平台上对阵列误差的校正算法进行了实验验证。通过与方位无关的校正矩阵校正之后,各阵元通道的复增益趋于一致,波达方向(DOA)估计精度也在误差允许范围之内。结果表明,这种阵列误差校正方法是行之有效的。 相似文献