共查询到20条相似文献,搜索用时 31 毫秒
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Yamada H. Ohmiya M. Ogawa Y. Itoh K. 《Antennas and Propagation, IEEE Transactions on》1991,39(2):177-183
Superresolution techniques for time delay estimation are proposed and applied to frequency-domain data measured with a network analyzer. A MUSIC (multiple signal classification) algorithm preprocessed by spatial smoothing is used. The spatial smoothing preprocessing is performed to destroy signal coherence, and the decorrelation performance is examined in detail. The expression which gives an individual response is given. Using this expression, it is possible to eliminate unwanted signals that appear as ripples in the frequency domain. Experimental results show that the frequency bandwidth required by the MUSIC algorithm to resolve distinct time-domain responses and eliminate unwanted signals is much narrower than that required by the FFT (fast Fourier transform). Thus, the MUSIC algorithm is applicable to the time-domain measurements with the network analyzer and has much higher resolution capability than the conventional FFT techniques. The MUSIC algorithm is one of the most promising methods of enhancing the accuracy of measurement for narrowband devices such as antennas 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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本文将能够精确描述高频电磁散射的几何绕射(GTD)模型取代传统的多重信号分类(MUSIC)算法所采用的指数和模型,并对MUSIC算法做了相应改进.提出利用特征分析方法的信号与噪声子空间正交特性,使改进后的MUSIC算法既能够精确估计目标散射中心位置,又能估计散射中心类型,取得了较好的效果.本文针对各种空间平滑预处理方法对噪声子空间与信号正交特性的影响进行了仿真,指出空间平滑预处理方法会影响噪声子空间及信号子空间结构,进而影响散射中心类型的估计,所以应对散射中心类型的最终结果进行修正. 相似文献
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Ma Changlin Peng Yingning Tian Lisheng Liu Jianhua 《电子科学学刊(英文版)》1998,15(4):289-295
A novel method to estimate DOA of coherent signals impinging on a uniform circular array( UCA) is presented in this paper. A virtual uniform linear array (VULA) is first derived by using spatial DFT technique, transforming the UCA from element space to phase mode space to obtain the properties of ordinary ULA, and then the well known spatial smoothing technique is applied to the VULA so that the lost rank of covariance matrix due to signal coherence can be retrieved. This method makes it feasible to use the simple MUSIC algorithm to estimate DOA of coherent signals impinging on a UCA without heavy computation burden. Simulation results strongly verify the effectiveness of the algorithm. 相似文献
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提出一种基于相干信号源的改进多重信号分类(IMUSIC)算法,以估计相干信号波达方向(DOA)。相干信号间接收数据特征值分解后,直接利用大特征值对应的信号子空间与信号导向矢量的关系,通过多维来波方向搜索谱峰,实现对来波方向的有效估计。与空间平滑算法相比,IMUSIC算法具有4大优点,仿真结果也验证了IMUSIC算法的有... 相似文献
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为了解决相干信号的极化平滑算法在小快拍数和低信噪比条件下估计性能较差的问题,结合四元数的正交特性和协方差张量方法,提出了一种基于张量四元数的极化平滑多重信号分类(Multiple Signal Classification,MUSIC)解相干算法。首先,为了充分利用接收数据样本中的多维结构信息,建立了由张量四元数表示的柱面共形阵列极化平滑信号模型;其次,将平滑后的张量协方差矩阵通过高阶奇异值分解得到信号子空间;最后,通过极化秩亏MUSIC算法对入射相干信号分别进行二维波达方向(Direction of Arrival,DOA)估计和极化参数估计。仿真结果表明,该算法在小快拍数和低信噪比条件下具有更高的估计精度和分辨能力。 相似文献
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该文提出一种基于宽带均匀同心球阵列(UCSA)的2维波达方向(2D-DOA)低复杂度估计算法.该方法将宽带UCSA输出信号转换为相位模式,并对其进行频率补偿,实现近似频率不变(FI)特性,从而降低宽带信号处理的计算复杂度.为了进一步降低2D-DOA估计的计算复杂度,该文提出基于FI-UCSA的降维多重信号分类(MUSI... 相似文献
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Lin J.-D. Fang W.-H. Wang Y.-Y. Chen J.-T. 《Signal Processing, IEEE Transactions on》2006,54(12):4529-4542
In this paper, we present a tree-structured frequency-space-frequency (FSF) multiple signal classification (MUSIC)-based algorithm for joint estimation of the directions of arrival (DOAs) and frequencies in wireless communication systems. The proposed approach is a novel twist of parameter estimation and filtering processes, in which two one-dimensional (1-D) frequency (F)- and one 1-D space (S)-MUSIC algorithms are employed-in a tree structure-to estimate the DOAs and frequencies, respectively. In between every other MUSIC algorithm, a temporal filtering process or a spatial beamforming process, implemented by a set of complementary projection matrices, is incorporated to partition the incoming rays to enhance the estimation accuracy, so that the incoming rays can be well resolved even with very close DOAs or frequencies, using the 1-D MUSIC algorithms. Also, with such a tree-structured estimation scheme, the estimated DOAs and frequencies are automatically paired without extra computational overhead. Furthermore, some statistical analyses of the undesired residue signals propagating between the 1-D MUSIC algorithms and the mean square errors of the parameter estimates are derived to provide further insights into the proposed approach. Simulations show that the new approach can provide comparable performance, but with reduced complexity compared with previous works, and that there is a close match between the derived analytic expressions and simulation results 相似文献
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针对时间反转(TR)多输入多输出(MIMO)雷达多重信号分类(MUSIC)算法计算量庞大的问题,提出一种基于时间反转的MIMO雷达实值MUSIC算法。首先,通过采用降维思想对TR MIMO回波信号进行降维处理,来减少计算量;然后,为将协方差矩阵转化到实数域,构造酉变换矩阵进行实值变换;最后,分解出实值协方差矩阵的噪声子空间,构造谱函数估计信号波达角。相对于传统的MUSIC算法,该算法借助实值变换剔除了复数运算,极大地降低了计算量,而且不需要空间平滑降低阵列孔径就具有解相干的能力。仿真结果证实了算法的正确性。 相似文献
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TST-MUSIC for joint DOA-delay estimation 总被引:11,自引:0,他引:11
Yung-Yi Wang Jiunn-Tsair Chen Wen-Hsien Fang 《Signal Processing, IEEE Transactions on》2001,49(4):721-729
A multiple signal classification (MUSIC)-based approach known as the time-space-time MUSIC (TST-MUSIC) is proposed to jointly estimate the directions of arrival (DOAs) and the propagation delays of a wireless multiray channel. The MUSIC algorithm for the DOA estimation is referred to as the spatial-MUSIC (S-MUSIC) algorithm. On the other hand, the temporal-MUSIC (T-MUSIC), which estimates the propagation delays, is introduced as well. Making use of the space-time characteristics of the multiray channel, the proposed algorithm-in a tree structure-combines the techniques of temporal filtering and of spatial beamforming with three one-dimensional (1-D) MUSIC algorithms, i.e., one S-MUSIC and two T-MUSIC algorithms. The incoming rays are thus grouped, isolated, and estimated. At the same time, the pairing of the estimated DOAs and delays is automatically determined. Furthermore, the proposed approach can resolve the incoming rays with very close DOAs or delays, and the number of antennas required by the TST-MUSIC algorithm can be made less than that of the incoming rays 相似文献
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针对色噪声背景下的相干信源波达方向估计问题,提出了一种空间平滑差分算法。该算法通过对空间平滑矩阵进行差分运算来对消色噪声,并采用PM算法进行方向估计。在去除噪声、减小计算量的同时,可估计较多的信源。由于算法对非相关信源和相关(或相干)信源同时估计,因此减小了算法实际实现的复杂度。计算机仿真结果证明了空间平滑差分算法理论的正确性和有效性。 相似文献
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DOA估计的一种改进MUSIC算法 总被引:1,自引:0,他引:1
讨论了在移动通信环境中采用协方差差分和迭代空间平滑以进行信号来波估计(Direction Of Arrival)的一种改进MUSIC算法.首先简要回顾了经典MUSIC算法,给出阵列接收信号模型,然后详细分析了经典MUSIC算法估计相干信号所存在的问题,在常规空间平滑算法(SS)的基础上提出了一种改进算法,最后给出计算机仿真结果并验证了新算法的有效性。 相似文献
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采用Radon-Wigner变换的二维波达方向估计 总被引:1,自引:0,他引:1
针对宽带多线性调频信号2维波达方向(2-D DOA)估计精度低的问题,该文提出了一种基于Radon-Wigner变换(RWT)的2-D DOA估计方法。该方法利用RWT在多目标环境下能够有效抑制交叉项干扰和噪声,具有很好的时频汇聚性特点,通过峰值搜索确定目标个数并重构信号阵列,最后利用MUSIC空间谱分析方法实现了对多个LFM信号的2-D DOA估计。仿真实验表明,基于RWT的DOA估计方法能对非平稳信号进行有效的2-D DOA估计。 相似文献