共查询到19条相似文献,搜索用时 89 毫秒
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采用Radon-Wigner变换方法,实现了噪声背景下单分量线性调频信号和多分量线性调频信号的检测。仿真结果表明,对于线性调频信号检测,Radon-Wigner变换方法性能明显优于Wigner-Ville分布法。 相似文献
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提出了一种基于Radon-Ambiguity变换(Radon-Ambiguity Transform, RAT)的线性调频(Linear Frequency Modulated, LFM)信号时/频差快速联合估计的算法.根据LFM信号在多个不同角度上的RAT峰值位置建立一组以信号间时差和频差为未知量的方程组,求解方程组即可得到时/频差的估计值.对于存在噪声的信号,RAT误差会导致方程组不能直接求解,为了抑制噪声干扰,采用最小二乘法估计时/频差.本文算法无需计算二维平面上各点的模糊函数值,并且由于离散RAT可以通过快速傅里叶变换快速实现,具有所需运算量低的优点.仿真实验表明,相比于常见的基于模糊函数峰值搜索的时/频差估计算法,本文算法在保证时/频差估计精度的同时能够显著提高运算效率. 相似文献
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基于快速折叠算法和时频分析的LPI跳频信号截获 总被引:1,自引:0,他引:1
该文提出了一种新的低截获概率(LPI)跳频信号的截获方法,该方法基于快速折叠算法和时频分析。在低信噪比环境下,该方法能有效检测跳频信号;通过恰当地选择折叠周期范围和分辨率,能实现对跳频参数如跳频周期、跳变时刻和跳频频率的估计。仿真结果和性能分析表明,该方法能有效截获信噪比为0dB的跳频信号,与自适应门限检测方法相比具有更好的性能。 相似文献
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本文简要介绍了四类离散余弦变换,以第二类离散余弦变换的快速算法为基础,从公式上推出了第四类离散余弦变换的快速算法,在运算次数上与直接计算进行了比较,并给出了相应的C程序。 相似文献
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详细探讨了合成孔径雷达中运动目标的检测问题,根据机载合成孔径雷达运动目标回波信号的特点,提出了基于Radon-Ambiguity变换和解调频技术的一种新的机载运动目标检测方法,给出了动目标检测、参数估计的主要步骤,分析了在单目标和多目标情况下的检测性能。该方法与常用的Wigner-Ville分布和Radon变换结合的方法相比计算量明显减少,在多目标情况下能够较好地抑制交叉项,提高检测性能。且使用解调频技术与RAT相配合,解决了单纯RAT无法估计Chirp信号初始频率的问题。仿真试验结果证明了算法的有效性。 相似文献
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随着科技的不断发展,高分辨宽测绘(High-Resolution and Wide-Swath, HRWS)SAR成像已经越来越受到人们的关注,具有地面动目标指示(Ground Moving Target Indication, GMTI)功能的SAR成像系统因其具有对静止场景进行高分辨成像和动目标检测能力在很多军用和民用领域受到广泛运用。具有HRWS成像能力的沿方位多通道SAR系统,其可以有效地解决高分辨和低脉冲重复频率(Pulse Repetition Frequency, PRF)的矛盾,该矛盾在HRWS成像处理过程中经常遇到。由于方位空域自由度可以用来进行杂波抑制,因此多通道构型具有提供GMTI潜能。该文提出一种新的杂波抑制和动目标的成像方法,使得在低PRF的HRWS系统进行SAR成像的同时可以完成动目标的检测与成像处理,而不需要单独的高PRF系统操作模式。 相似文献
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Fast Discrete Cosine Transform via Computation of Moments 总被引:2,自引:0,他引:2
Discrete cosine transform (DCT) is widely used in signal processing. This paper presents a novel approach to perform DCT. DCT is expressed in terms of discrete moments via triangle function transforms and later Taylor series expansion. From this, a fast systolic array for computing moments is converted to compute DCT with only a few multiplications and without any cosine evaluations. The systolic array has advantages of pipelinability, regularity, modularity, local connectivity and scalability, thus making it to be very suitable for VLSI implementation. We provide an estimate of the realizability of our array in a 0.5 m CMOS technology and comparisons with other methods. The execution time of the systolic array is only O(N log2
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N) in computing 1D N-point DCT if N is sufficiently large. The approach is also applicable to multiple dimensional DCT and DCT inverses. 相似文献
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星载SAR的轨道运动和受地球自转、地球曲率等因素影响,以及卫星平台快速运动造成的地杂波谱展宽甚至占据整个方位谱,这些都使得星载SAR/GMTI的处理方法较机载SAR/GMTI更为复杂.为了有效检测运动目标,必须对地杂波进行抑制.偏置天线相位中心(DPCA)是一种有效的地杂波抑制技术.文中在星载SAR三孔径天线回波信号多普勒特性分析的基础上,结合Raney,R K给出的多普勒参数表达式,推导了一种基于DPCA的星载SAR动目标检测、径向速度分量估计以及目标定位的方法.最后,通过星载SAR/GMTI计算机仿真进行了验证. 相似文献
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微动特性干扰主要模拟了微动目标对合成孔径雷达图像的方位扩展影响,其成像特性已经得到了比较好的研究,但是对SAR/GMTI的影响研究还不充分.本文主要分析了基于分数阶傅里叶变换的多孔径SAR/GMTI的原理,根据分数阶傅里叶变换的本质和该方法下的杂波对消、干涉相位的响应特性,结合了微动干扰的多普勒特性,初步研究了在旋转角... 相似文献
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In this paper, a new systolic array for prime N-length DFT is first proposed, and then combined with Winograd Fourier Transform algorithm (WFTA) to control the increase
of the hardware cost when the transform length is large. The proposed new DFT design is both fast and hardware efficient.
Compared with the recently reported DFT design with computational complexity of O(log N), the proposed design saves the average number of required multiplications by 30 to 60% and reduces the average computation
time by more than 2 times, when the transform length changes from 16 to 2048.
Chao Cheng received his MSEE degree from Huazhong University of Science and Technology, Wuhan, China, in 2001. With three years industrial
experience as a digital communication engineer from VIA Technologies, he is now pursuing his Ph.D. degree at the University
of Minnesota, Twin Cities, MN.
His present research interest is in VLSI digital signal processing algorithms and their implementation.
Keshab K. Parhi received his B.Tech., MSEE, and Ph.D. degrees from the Indian Institute of Technology, Kharagpur, the University of Pennsylvania,
Philadelphia, and the University of California at Berkeley, in 1982, 1984, and 1988, respectively. He has been with the University
of Minnesota, Minneapolis, since 1988, where he is currently Distinguished McKnight University Professor in the Department
of Electrical and Computer Engineering.
His research addresses VLSI architecture design and implementation of physical layer aspects of broadband communications systems.
He is currently working on error control coders and cryptography architectures, high-speed transceivers, and ultra wideband
systems.
He has published over 400 papers, has authored the text book VLSI Digital Signal Processing Systems (Wiley, 1999) and coedited
the reference book Digital Signal Processing for Multimedia Systems (Marcel Dekker, 1999).
Dr. Parhi is the recipient of numerous awards including the 2004 F.E. Terman award by the American Society of Engineering
Education, the 2003 IEEE Kiyo Tomiyasu Technical Field Award, the 2001 IEEE W.R.G. Baker prize paper award, and a Golden Jubilee
award from the IEEE Circuits and Systems Society in 1999.
He has served on the editorial boards of the IEEE TRANSACTIONS ON CAS, CAS-II, VLSI Systems, Signal Processing, Signal Processing
Letters, and Signal Processing Magazine, and currently serves as the Editor-in-Chief of the IEEE Trans. on Circuits and Systems---I
(2004--2005 term), and serves on the Editorial Board of the Journal of VLSI Signal Processing.
He has served as technical program cochair of the 1995 IEEE VLSI Signal Processing workshop and the 1996 ASAP conference,
and as the general chair of the 2002 IEEE Workshop on Signal Processing Systems. He was a distinguished lecturer for the IEEE
Circuits and Systems society during 1996--1998. He is a Fellow of IEEE (1996).
An erratum to this article is available at . 相似文献