共查询到10条相似文献,搜索用时 125 毫秒
1.
Direction of arrival (DOA) estimation is one of the key technologies in smart antennas in the direct sequence ultra wideband
(DS-UWB) system. Traditional DOA estimation methods based on narrow-band signals are not suitable for such system. Therefore,
a fourth-order cumulant-based estimation method ofDOA for DS-UWB signal is proposed. This method is set on the frequency domain
model of DS-UWB array signal. Simulation results show that the algorithm is effective and can guarantee adequate estimation
accuracy.
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Translated from Journal of University of Electronic Science and Technology of China, 2007, 36(2): 190–192 [译自: 电子科技大学学报] 相似文献
2.
Ying LIU Guisheng LIAO Zhengguang ZHOU 《Frontiers of Electrical and Electronic Engineering in China》2008,3(4):425-434
The performance of ground moving target detection for distributed satellites will be affected significantly when there is
an image registration error, clutter decorrelation and array error. In this paper, a new approach to moving target detection
and relocation is proposed based on multi-channel and multi-pixel adaptive signal processing in an image domain. First, multichannel
and multi-pixel joint data are equated to a simple array model. Given that there is an image registration error, the real
steering vector of the moving target can be estimated through a space projection approach. The optimal beam forming approach
is used to cancel clutter, and at the same time the cross-track velocity of the moving target can be determined by searching
for the peak value of the cost function. The moving target can then be relocated on the SAR image. The simulation results
indicate that this method has a good robustness to image registration error, clutter decorrelation and array error. The detection
performance and the estimation accuracy are significantly improved.
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Translated from Acta Electronica Sinica, 2007, 35(6): 1009–1014 [译自: 电子学报] 相似文献
3.
Yun Zhang Boqin Feng Shouqiang Ma Lianmeng Liu 《Frontiers of Electrical and Electronic Engineering in China》2009,4(1):15-19
Focusing on the problem that the ant colony algorithm gets into stagnation easily and cannot fully search in solution space,
a text clustering approach based on the fusion of the ant colony and genetic algorithms is proposed. The four parameters that
influence the performance of the ant colony algorithm are encoded as chromosomes, thereby the fitness function, selection,
crossover and mutation operator are designed to find the combination of optimal parameters through a number of iteration,
and then it is applied to text clustering. The simulation results show that compared with the classical k-means clustering and the basic ant colony clustering algorithm, the proposed algorithm has better performance and the value
of F-Measure is enhanced by 5.69%, 48.60% and 69.60%, respectively, in 3 test datasets. Therefore, it is more suitable for processing
a larger dataset.
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Translated from Journal of Xi’an Jiaotong University, 2007, 41(10): 1146–1150 [译自: 西安交通大学学报] 相似文献
4.
A new mutual coupling compensation method based on a new mutual impedance matrix, as well as its application to dipole arrays,
are proposed. This new mutual impedance matrix is deduced by electromotive force (EMF) method, based on the current distribution
obtained by the characteristic basis function method. It appears in a concise and explicit formulation that facilitates the
numerical calculation. The compensation performance is demonstrated and evaluated through its application in direction of
arrival (DOA) estimation. Numerical results show that the proposed method exhibits excellent compensation performance compared
with conventional mutual impedance matrix approaches.
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Translated from Chinese Journal of Radio Science, 2007, 22(4): 541–545 [译自: 电波科学学报] 相似文献
5.
Zhiwei Li Chunyan Feng Tiankui Zhang Jieying Zheng 《Frontiers of Electrical and Electronic Engineering in China》2009,4(1):31-34
To coordinate inter-cell interference, a multicell adaptive power allocation scheme is proposed for downlink orthogonal frequency
division multiple access (OFDMA) cellular systems. This scheme uses the difference of the signal to interference plus noise
ratio (SINR) between the co-subchannels of adjacent cells to balance SINR for coordinating the transmit power in the co-subchannels.
The scheme can improve edge user performance, reduce interference between the co-subchannels of adjacent cells and improve
radio resource utility. Simulation results show that the scheme can balance system performance and ensure system throughput.
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Translated from Journal of Beijing University of Posts and Telecommunications, 2008, 31(1): 71–74 [译自: 北京邮电大学学报] 相似文献
6.
An adaptive background model based on maximum statistical probability and a shadow suppression scheme for indoor and outdoor
people detection by exploiting hue saturation value (HSV) color information is proposed. To obtain the initial background
scene, the frequency of R, G, and B component values for each pixel at the same position in the learning sequence are respectively
calculated; the R, G, and B component values with the biggest ratios are incorporated to model the initial background. The
background maintenance, or the socalled background re-initiation, is also proposed to adapt to scene changes such as illumination
changes and scene geometry changes. Moving cast shadows generally exhibit a challenge for accurate moving target detection.
Based on the observation that a shadow cast on a background region lowers its brightness but does not change its chromaticity
significantly, we address this problem in the article by exploiting HSV color information. In addition, quantitative metrics
is introduced to evaluate the algorithm on a benchmark suite of indoor and outdoor video sequences. The experimental results
are given to show the performance of the algorithm.
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Translated from Journal of Huaqiao University (Natural Science), 2007, 28(1): 30–33 [译自: 华侨大学学报 (自然科学版)] 相似文献
7.
Weihong FU Xiaoniu YANG Nai''an LIU Xingwen ZENG 《Frontiers of Electrical and Electronic Engineering in China》2008,3(3):338-342
Most blind source separation algorithms are only applicable to real signals, while in communication reconnaissance processed
signals are complex. To solve this problem, a blind source separation algorithm for communication complex signals is deduced,
which is obtained by adopting the Kullback-Leibler divergence to measure the signals’ independence. On the other hand, the
performance of natural gradient is better than that of stochastic gradient, thus the natural gradient of the cost function
is used to optimize the algorithm. According to the conclusion that the signal’s mixing matrix after whitening is orthogonal,
we deduce the iterative algorithm by constraining the separating matrix to an orthogonal matrix. Simulation results show that
this algorithm can efficiently separate the source signals even in noise circumstances.
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Translated from Journal of Huazhong University of Science and Technology (Natural Science Edition), 2007, 35(4): 33–36 [译自: 华中科技大学学报(自然科学版)] 相似文献
8.
Guobing Li Shihua Zhu Hui Hui 《Frontiers of Electrical and Electronic Engineering in China》2009,4(2):149-154
To enhance the performance of opportunistic cooperative relaying systems, this paper proposes power allocation algorithms
aimed at minimizing the outage probability. The optimization model of the system is constructed and proved to be a convex
optimization problem. Then the optimal power allocation algorithm and its operation steps are presented. Furthermore, a simple
and effective near-optimal power allocation strategy is developed, which only depends on the average channel gains of the
relays and thus incurs little overhead. Simulation and numerical results show that significant performance gains can be achieved
by the two proposed power allocation algorithms.
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Translated from Acta Electronica Sinica, 2008, 36(10): 1944–1948 [译自: 电子学报] 相似文献
9.
Tian Ye Sheng Min Li Jiandong 《Frontiers of Electrical and Electronic Engineering in China》2007,2(4):459-463
This paper presents a novel distributed media access control (MAC) address assignment algorithm, namely virtual grid spatial
reusing (VGSR), for wireless sensor networks, which reduces the size of the MAC address efficiently on the basis of both the
spatial reuse of MAC address and the mapping of geographical position. By adjusting the communication range of sensor nodes,
VGSR algorithm can minimize the size of MAC address and meanwhile guarantee the connectivity of the sensor network. Theoretical
analysis and experimental results show that VGSR algorithm is not only of low energy cost, but also scales well with the network
size, with its performance superior to that of other existing algorithms.
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Translated from Journal of Xidian University, 2006, 33(5): 716–720 [译自: 西安电子科技大学学报 (自然科学版)] 相似文献
10.
Liu Yusheng Li Xingyuan 《Frontiers of Electrical and Electronic Engineering in China》2007,2(3):282-287
The ideas of adaptive nonlinear damping and changing supply functions were used to counteract the effects of parameter and
nonlinear uncertainties, unmodeled dynamics and unknown bounded disturbances. The high-gain observer was used to estimate
the state of the system. A robust adaptive output feedback control scheme was proposed for nonlinearly parameterized systems
represented by input-output models. The scheme does not need to estimate the unknown parameters nor add a dynamical signal
to dominate the effects of unmodeled dynamics. It is proven that the proposed control scheme guarantees that all the variables
in the closed-loop system are bounded and the mean-square tracking error can be made arbitrarily small by choosing some design
parameters appropriately. Simulation results have illustrated the effectiveness of the proposed robust adaptive control scheme.
Translated from Journal of Sichuan University (Engineering Science Edition), 2006, 38(4): 136–140 [译自: 四川大学学报 (工程科学版)] 相似文献