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脉冲噪声环境下波达方向(DOA)估计是阵列信号处理领域一个新兴研究方向。针对α稳定分布噪声环境下经典MUSIC算法性能退化的问题,提出了一种新的基于非线性压缩核函数(NCCF)的DOA估计算法。该算法利用基于NCCF的有界矩阵代替了MUSIC的协方差矩阵,通过对有界矩阵进行特征分解确定信号子空间和噪声子空间,借用MUSIC谱估计公式进行谱峰搜索,得到DOA的估计值。仿真结果表明,NCCF-MUSIC算法运算复杂度较低,相比于基于分数低阶统计量(FLOS)的MUSIC方法和基于广义类相关熵(GCAS)的MUSIC算法,该方法具有更好的准确度和稳定性。 相似文献
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以Alpha稳定分布作为噪声模型,研究了脉冲噪声环境下宽带双基地MIMO雷达系统中参数估计问题.针对在脉冲噪声环境中,基于传统的信号模型和算法效果显著退化的问题,本文提出了基于分数低阶统计量的宽带模糊函数算法.首先根据分数低阶宽带模糊函数的峰值点实现对多普勒频率尺度因子和时延的联合估计.接下来基于分数低阶宽带模糊函数构造两个子阵.通过采用改进的MUSIC算法和ESPRIT算法实现了收发角的联合估计.仿真实验表明本文算法具有很好的性能. 相似文献
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作为阵列信号处理的一个基本问题,波达方向估计在现代通信领域有着广泛的应用。常规估计方法通常基于高斯噪声假设。 而当阵列接收数据包含 Alpha 稳定分布脉冲噪声时算法将完全失效。针对 Alpha 稳定分布噪声下的波达方向估计问题,本文定义了一种改进的相关熵算子——中值离差相关熵,并从理论上证明了它的有界性。 以此为基础结合 MUSIC 算法提出了一种波达方向估计新方法。该方法不需要噪声先验知识,且在脉冲噪声环境中具有鲁棒性。仿真实验表明, 即使在短快拍、强脉冲噪声的恶劣环境下,本文方法依然具有良好的性能。 相似文献
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针对传统MQAM信号载频与符号率估计算法在脉冲噪声下性能不佳甚至失效的问题,该文结合分数低阶矩与共变理论,推导了MQAM的分数低阶循环谱密度函数,并分析了升余弦脉冲成型条件下的MQAM信号循环谱特征。将分数低阶矩引入离散频域平滑谱(DFSM)估计。提出了一种基于分数低阶矩的MQAM载波频率与符号率联合参数估计算法,采用相邻谱切面求平均的方法,有效的避免了由于分辨率不足造成估计误差。仿真实验结果表明,与二阶DFSM循环谱估计算法相比,本文算法不仅能够抑制脉冲噪声的影响,而且在较为恶劣的噪声条件下均能有效的估计MQAM信号的载频与符号率,具有更好的抗干扰能力与适用性,适用于不同调制阶数的MQAM信号。 相似文献
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研究了冲击噪声环境下相干信源波达方向(DOA)估计问题.在对称α稳定分布冲击噪声假设下,基于共变和分数低阶矩的MUSIC(即ROC-MUSIC和FLOM-MUSIC)方法不能用于相干信源DOA估计.本文首次将空间平滑思想应用于共变系数矩阵和分数低阶矩矩阵中,定义了新的前后向平滑共变系数矩阵和前后向平滑分数低阶矩矩阵,提出了两种新的适用于冲击噪声环境的相干信源DOA估计方法:基于前后向平滑共变系数矩阵的空间平滑(ROC-SS)算法和基于前后向平滑分数低阶矩矩阵的空间平滑(FLOM-SS)算法.理论分析表明,可以通过前后向平滑共变系数矩阵和前后向平滑分数低阶矩矩阵的特征分解来估计噪声子空间,从而实现对相干信源的DOA估计.论文还对提出的ROC-SS算法和FLOM-SS算法进行了性能对比分析.计算机仿真结果证明了ROC-SS算法和FLOM-SS算法的有效性和正确性. 相似文献
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Guo-hong You Tian-shuang Qiu Ai-min Song 《Circuits, Systems, and Signal Processing》2013,32(6):2939-2956
We consider the problem of direction-of-arrival (DOA) estimation for cyclostationary signals in impulsive noise modeled as a complex symmetric α-stable (SαS) process. Since the DOA estimation based on second-order cyclic statistics degrades seriously in an α-stable distribution noise environment, we define a novel pth-order cyclic correlation by fusing the fractional lower order statistics and second-order cyclic correlation. After briefly introducing the statistical characteristics of pth-order cyclic correlation and building the extended data model, we first propose a novel extended pth-order cyclic MUSIC algorithm (EX-POC-MUSIC) by exploiting both pth-order cyclic correlation and pth-order cyclic conjugate correlation. The algorithm allows us to select desired signals and to ignore interference in the communication system. Second, in order to increase the resolution capabilities and the noise robustness significantly, an improved EX-POC-MUSIC algorithm called the extended pth-order cyclic Root-MUSIC (EX-POC-RMUSIC) algorithm is also presented. This algorithm has all the merits of the EX-POC-MUSIC algorithm, and it is also a fast DOA estimation algorithm because it avoids spatial spectrum searching. Under some conditions, both proposed algorithms are able to handle more sources than the number of sensors. Simulation results strongly verify the effectiveness of the two algorithms. 相似文献
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Guo-hong You Tian-shuang Qiu Jiao Yang 《AEUE-International Journal of Electronics and Communications》2013,67(6):491-499
Co-channel interference is a common existence in communication system, which will result in the deterioration for directions-of-arrival (DOAs) estimation. To solve this problem, a fractional lower order cyclic MUSIC method suitable for uniform circular array (UCA) is presented. The proposed method can eliminate both impulsive-noise and interference in the same frequency band, and it also performs well in Gaussian noise. Especially, the algorithm can be applied to either narrow or broad-band signal models. Simulation results strongly verify the high performance of this method. 相似文献
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Alpha稳定分布噪声环境下类M估计相关的DOA估计新算法 总被引:1,自引:0,他引:1
提出了一类适用于Alpha稳定分布随机变量的统计量—类M估计相关(MELC),通过构造阵列输出的类M估计相关矩阵,提出了适用于Alpha稳定分布噪声环境下的波达方向(DOA)估计新算法,即MELC-MUSIC算法。仿真实验表明,在Alpha稳定分布噪声环境下,MELC-MUSIC算法在抗噪声特性、多源信号分辨性以及对不同形式信号(圆对称信号或非圆对称信号)的适应性方面获得比基于分数低阶统计量(FLOS)的MUSIC方法更好的估计性能。 相似文献
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基于分数低阶统计量的空域-模糊域DOA估计算法 总被引:1,自引:0,他引:1
该文提出一种非高斯SS噪声背景下非平稳信号的DOA估计算法。算法首先定义基于分数低阶统计量的空间模糊函数,利用信号在模糊域中的不同特征将信号分离;然后对不同的信号,选择信号模糊函数对应的模糊点的平均进行子空间分析;最后利用MUSIC算法实现DOA的估计。与基于分数低阶统计量的空域处理方法相比,该文提出的算法利用了信号在模糊域中的信息,提高了算法的估计精度。计算机仿真证明了算法的有效性。 相似文献
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This paper takes an Alpha-stable distribution as the noise model to solve the parameter estimation problem of bistatic multiple-input multiple-output (MIMO) radar system in the impulsive noise environment. For a moving target, its echo often contains a time-varying Doppler frequency. Furthermore, the echo signal may be corrupted by a non-Gaussian noise. It causes the conventional algorithms and signal models degenerating severely in this case. Thus, this paper proposes a new signal model and a novel method for parameter estimation in bistatic MIMO radar system in the impulsive noise environment. It combines the fractional lower-order statistics (FLOS) and fractional power spectrum density (FPSD), for suppressing the impulse noise and estimating parameters of the target in fractional Fourier transform domain. Firstly, a new signal array model is constructed based on the \(\alpha \)-stable distribution model. Secondly, Doppler parameters are jointly estimated by peak searching of the FLOS–FPSD. Furthermore, two modified algorithms are proposed for the estimation of direction-of-departure and direction-of-arrival (DOA), including the fractional power spectrum density based on MUSIC algorithm (FLOS–FPSD–MUSIC) and the fractional lower-order ambiguity function based on ESPRIT algorithm (FLOS–FPSD–ESPRIT). Simulation results are presented to verity the effectiveness of the proposed method. 相似文献
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在冲击噪声环境中,包括MUSIC、ESPRIT和MNM在内的传统DOA算法估计性能急剧下降甚至失效,因此出现了一些基于分数低阶矩的稳健性算法,例如ROC-MUSIC和FLOM-MUSIC等。虽然在冲击噪声环境下,这些稳健性算法具有很好的工作性能,但是这些算法需要进行计算量较大的复数特征分解,从而不适宜实现DOA的快速有效估计。为了解决这一问题,提出了一种快速实值算法(FRA),由于该算法可在实数域工作并且不需要进行特征分解,所以它的计算量远小于现有算法,在同等条件下更有利于快速地估计DOA。计算机仿真证明该算法具有优良的DOA估计性能,适宜在冲击噪声环境下应用。 相似文献
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基于Screened Ratio原理的冲击噪声环境下DOA估计算法 总被引:2,自引:0,他引:2
该文提出了一种冲击噪声环境中DOA估计的算法。算法首先根据Screened ratio原理构造阵列信号的相关矩阵,然后利用MUSIC算法实现DOA估计。与基于分数低阶矩(FLOM)的算法相比,该文算法不需要选择FLOM参数p。计算机仿真表明该文算法在冲击噪声环境下具有更佳的稳定性和估计精度。 相似文献
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An extended cyclic MUSIC algorithm 总被引:9,自引:0,他引:9
Many modulated communication signals exhibit a cyclostationarity (or periodic correlation) property, corresponding to the underlying periodicity arising from carrier frequencies or baud rates. In this paper, we propose a new MUSIC-like direction-finding algorithm that exploits cyclostationarity in order to improve the direction-of-arrival (DOA) estimation. Both cyclic and conjugate cyclic correlation matrices are used in the proposed method so that it can be considered as an extension of the cyclic MUSIC algorithm . The proposed cyclic method allows an increase in resolution power and noise robustness. Depending on the modulation type of incoming signals, the proposed method is also able to handle more sources than the number of sensors. 相似文献
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为了提高脉冲噪声环境下基于二阶协方差矩阵差分(COV-MD)的远近场混合源定位算法的估计性能,本文提出了基于分数低阶协方差矩阵差分(FLOC-MD)和基于压缩变换协方差矩阵差分(CTC-MD)的远近场混合源定位算法。所提出的算法首先利用一维MUSIC谱峰搜索获得远场源信号的方位角估计,然后利用矩阵差分法实现远近场信号源的分离得到扩展的近场源分数低阶协方差矩阵(或压缩变换协方差矩阵),最后在利用类旋转不变方法(ESPRIT-Like)估计得到的近场源方位角的基础上,再次利用一维MUSIC谱峰搜索获得近场源距离的估计。计算机仿真结果表明:CTC-MD算法和FLOC-MD算法在强脉冲和低信噪比情况下的估计性能都要明显优于COV-MD算法和其他基于二阶统计量的远近场混合源定位算法,同时CTC-MD算法的性能要好于FLOC-MD算法并且不依赖于脉冲噪声的先验信息。 相似文献