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非高斯有色噪声中基于四阶累积量噪声建模的谐波恢复方法 总被引:3,自引:1,他引:2
本文提出一种在非高斯ARMA噪声中谐波恢复的高阶累积量方法,该方法首先通过Hiblert变换构造复数观测值,然后使用它的一种特殊的四阶累积量建立噪声过程AR参数,由此对观测值滤波,最后通过SVD-TLS方法估计谐波信号参数,本文方法克服了以往对非高斯噪声分布的非对称性假设,成功地解决了对称分布非高斯有色噪声中的谐波恢复问题,并且适用于于谐波信号存在二次相应耦合情形,仿真实验验证了文中结论。 相似文献
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基于四阶累积量的重叠语音分离 总被引:3,自引:0,他引:3
文章将文献「1」给出的信号盲分离的一个理论判据应用于实际重叠语音信号的分离,给出了实现该判据的迭代算法,并对其中的参数选择等进行了讨论。实验表明,对于由两个语音分量构成的重叠语音信号,只要合理地选择其参数,就能有效地将其分离。 相似文献
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针对现有稀疏重构DOA估计算法不能抑制噪声项以及在高斯色噪声背景下不再适用的问题,本文提出了基于四阶累积量稀疏重构的DOA估计方法。首先,利用接收数据的四阶累积量构建了稀疏表示模型,该模型抑制了噪声项;其次对四阶累计量矩阵进行奇异值分解,化简了稀疏表示模型,通过奇异值分解,不仅减小了数据规模,而且进一步抑制了噪声。对于稀疏表示模型的求解,先利用信号子空间与噪声子空间的正交特性选取权值矢量,然后利用加权l1范数法对模型求解实现DOA估计。理论分析和仿真实验表明本文算法在高斯白噪声和色噪声背景下均适用;能够处理非相干和相干信号,且在低信噪比条件下,对相干信号有更高的估计精度;较之同类的稀疏重构算法,本文算法具有较低的算法复杂度和更高的角度分辨力。 相似文献
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对通信系统中大量使用的BPSK等非圆信号测向,可以采用共轭扩展MUSIC(CE-MUSIC)算法,也可以采用基于四阶累积量的MUSIC-like算法。CE-MUSIC算法没有利用高阶信息,MUSIC-like算法没有利用信号的非圆信息,性能均受限。该文提出的四阶扩展MUSIC(FO-EMUSIC)算法利用了非圆信号在四阶累积量中的信息,分辨力和测角精度明显优于MUSIC-like算法,略优于CE-MUSIC算法,可测向阵元数大于CE-MUSIC算法和MUSIC-like算法。针对均布线阵,为减小计算量,还提出了FO-EMUSIC/ULA算法。仿真实验验证了FO-EMUSIC算法的优良性能。 相似文献
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散射中心是目标光学区电磁散射的基本特征,可反映目标精细物理结构.在建立精确描述目标高频电磁散射的三维CP-GTD模型的基础上,根据散射中心类型和位置参数的弱耦合性,提出基于三维ESPRIT方法估计目标全极化三维散射中心的位置,进而利用特征分析中信号子空间与噪声子空间的正交性和最小二乘方法,实现散射中心类型和相干极化散射矩阵的估计.与现有基于单极化观测模型的估计方法相比,所提方法不仅具有更好的估计性能与抗噪能力,而且能够直接估计出目标散射中心的相干散射矩阵,仿真实验验证了上述结论的正确性. 相似文献
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由于共形天线阵列流形的多极化特性(Polarization Diversity),共形阵列天线的信源方位估计需要与信源的极化状态联合进行。分析总结共形阵列天线波达方向(DOA)估计特点的基础上,针对窄带远场非高斯独立信源,提出了一种共形阵列天线盲极化DOA估计算法。该算法利用四阶累积量对阵列口径的扩展性,结合旋转不变子空间(ESPRIT)算法,在信源极化状态未知条件下实现了共形阵列天线的高分辨DOA估计。所提算法的方位估计不需要天线单元方向图以及信源极化状态的任何信息,适用于多种常用共形载体(锥面、柱面以及球面共形载体),具有较为广泛的应用环境。以柱面共形阵列天线DOA估计为例,详细推导了算法机理,给出了算法步骤,计算机Monte Carlo仿真实验验证了所提算法的有效性。 相似文献
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为解决多天线最佳接收下的多维非高斯噪声参数估计问题,提出了基于群蒙特卡洛的大气噪声二维模型参数估计方案,通过联合设计蒙特卡洛马尔科夫链和优化重要性重采样算法,实现噪声模型的全局最优参数估计。针对该算法高强度运算需求,在GPU平台上对核心运算作细粒度并行计算处理并优化设计,使运算速度大幅提升,以满足实时处理要求。仿真实验结果表明,该算法迭代收敛快,精度高,各参数估计相对误差普遍小于0.02,最大相对误差可控制在0.05以内,运算速度较传统计算有大幅度的提高,可充分满足低频通信系统中实时计算的要求。 相似文献
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综合利用高光谱图像的光谱信息和空间信息,提出了一种新的混合噪声评估方法.首先通过滤波算法进行图像中均匀图像块的自动选取;然后利用多元线性回归模型,将均匀图像块内像素点的信号值和噪声值进行分离,并实现了图像中加性、乘性噪声的粗评估;最后根据噪声模型构建似然函数,利用最大似然估计法求解噪声模型参数.通过仿真图像和真实高光谱图像进行实验,验证了该方法的准确性和鲁棒性. 相似文献
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In this paper, we consider the problem of parameter estimation of autoregressive (AR) signals from observations corrupted with colored AR(1) noise. The proposed method is based on Yule-Walker equations. We express these equations as a quadratic eigenvalue problem and then the parameters of the signal and noise are estimated by solving this eigenvalue problem. We also apply the proposed method to the problem of sinusoidal frequency estimation in colored noise. The performance of the proposed algorithm is evaluated by computer simulation examples. 相似文献
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《Digital Communications & Networks》2019,5(2):76-83
In this paper, the problem of high mobility channel estimation in the Long-Term Evolution for Railway (LTE-R) communication system is investigated. By using a Basis Expansion Model (BEM), the channel impulse response is modeled as the sum of several basis functions multiplied by coefficients. By estimating the basis function coefficients, the fast time-varying channel can be approximated. In order to reduce the estimation error resulting from the high frequency basis function, the Generalized Complex Exponential BEM (GCE-BEM) is modified to form an Improved GCE-BEM (IGCE-BEM) by adding a correction coefficient to the basis function. Moreover, an Improved Baseline Tilting (IBT) method is proposed to reduce the Gibbs effect. In addition, linear interpolation, Gauss interpolation, and three-order Hermite interpolation are adopted to obtain the channel impulse response at non pilot locations based on the channel estimation results at pilot positions. The simulation results show that the IGCE-BEM outperforms the CE-BEM and GCE-BEM in terms of the Normalized Mean Squared Error (NMSE). The IBT method is better than the BT method in reducing the Gibbs effect. In addition, combined with the IBT, the IGCE-BEM also has low NMSE under high moving speed and high noise power. The performance of the three-order Hermite interpolation method is higher than that of the linear interpolation and Gauss interpolation approaches. 相似文献
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JIN Yan JI Hongbing 《电子学报:英文版》2008,(2):309-313
The problem of concern here is parameter estimation of chirp signals in the presence of multiplicative and additive noise. An improved cyclostationarity based algorithm is proposed to estimate the phase parameters. The novelty of the proposed algorithm lies in the iterative estimation of the second-order parameters. The main characteristics of the method include reduction in error propagation effect, increase in estimation accuracy, and operation over a wider range of phase parameter values. Simulation results demonstrate that the proposed algorithm has better performance than the conventional cyclostationary estimation method. 相似文献
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Li Li Tian-shuang Qiu De-rui Song 《AEUE-International Journal of Electronics and Communications》2013,67(11):947-954
This paper takes the alpha-stable distribution as the noise model and works on the parameter estimation problem of wideband bistatic Multiple-Input Multiple-Output (MIMO) radar system in the impulsive noise environment. In many applications, it is not appropriate to approximate the wideband signal by the narrowband model. Furthermore, the echo signal may be corrupted by the non-Gaussian noise. The conventional algorithms degenerate severely in the impulsive noise environment. Thus, this paper proposes a new wideband signal model and a novel method in wideband bistatic MIMO radar system. It combines the fractional lower order statistics and fractional power spectrum, for suppressing the impulse noise and estimating parameters of the target. Firstly, a new signal array model is proposed under the alpha-stable distribution noise model. Secondly, Doppler stretch and time delay are jointly estimated by peak searching of the FLOS-FPSD. Furthermore, two modified algorithms are proposed for the estimation of the direction-of-departure and direction-of-arrival, 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