在对基本 LMS算法进行修改的基础上 ,提出了基于高阶累积量极性 -动量迭代的自适应线性调频 ( Linear Frequency Modulation,LFM)信号增强新算法。该算法有抑制高斯噪声效果好 ,计算量小 ,收敛快且输出信号平稳等特点。仿真结果证实了...在对基本 LMS算法进行修改的基础上 ,提出了基于高阶累积量极性 -动量迭代的自适应线性调频 ( Linear Frequency Modulation,LFM)信号增强新算法。该算法有抑制高斯噪声效果好 ,计算量小 ,收敛快且输出信号平稳等特点。仿真结果证实了该算法的有效性和可靠性。因此 ,具有较强的实用性和较好的应用前景。展开更多
Compared to the rank reduction estimator （RARE） based on second-order statistics （called SOS-RARE）, the RARE employing fourth-order cumulants （referred to as FOC-RARE） is capable of dealing with more sources and...Compared to the rank reduction estimator （RARE） based on second-order statistics （called SOS-RARE）, the RARE employing fourth-order cumulants （referred to as FOC-RARE） is capable of dealing with more sources and mitigating the negative influences of the Gaussian colored noise. However, in the presence of unexpected modeling errors, the resolution behavior of the FOC-RARE also deteriorate significantly as SOS-RARE, even for a known array covariance matrix. For this reason, the angle resolution capability of the FOC-RARE was theoretically analyzed. Firstly, the explicit formula for the mathematical expectation of the FOC-RARE spatial spectrum was derived through the second-order perturbation analysis method. Then, with the assumption that the unexpected modeling errors were drawn from complex circular Gaussian distribution, the theoretical formulas for the angle resolution probability of the FOC-RARE were presented. Numerical experiments validate our analytical results and demonstrate that the FOC-RARE has higher robustness to the unexpected modeling en＇ors than that of the SOS-RARE from the resolution point of view.展开更多
Both noise and time delay play important roles in regulating the dynamical behavior in complex systems, such as chemical oscillator, nonlinear circuits, nerve system and networks. It is ever thought that noise can cau...Both noise and time delay play important roles in regulating the dynamical behavior in complex systems, such as chemical oscillator, nonlinear circuits, nerve system and networks. It is ever thought that noise can cause breakdown or irregularity of the nonlinear dynamical systems, for example, the thermal noise in circuit could decrease the quality of signals. Indeed, noise often plays a positive role in excitable media; it is found that the regularity can be enhanced under intermediate noise intensi- ty. One distinct example is supported as coherence resonance or stochastic resonance that appropriate noise intensity can en- hance the temporal order, regularity, signal-to-noise ratio （SNR）, and even spatial regularity in network. In theoretical studies, Gaussian white noise, Gaussian colored noise, L（vy noise, and phase noise are often considered in additive or multiplicative type. For biological neurons, channel noise is often considered for transition of electric activities. In the field of pattern selec- tion and control, it is found that noise often cause breakup of target wave and spiral wave, while appropriate noise intensity is important to support the emergence of spiral wave that keeps the network under distinct spatial regularity like a pacemaker.展开更多
基金Project(61201381)supported by the National Nature Science Foundation of ChinaProject(YP12JJ202057)supported by the Future Development Foundation of Zhengzhou Information Science and Technology College,China
文摘Compared to the rank reduction estimator （RARE） based on second-order statistics （called SOS-RARE）, the RARE employing fourth-order cumulants （referred to as FOC-RARE） is capable of dealing with more sources and mitigating the negative influences of the Gaussian colored noise. However, in the presence of unexpected modeling errors, the resolution behavior of the FOC-RARE also deteriorate significantly as SOS-RARE, even for a known array covariance matrix. For this reason, the angle resolution capability of the FOC-RARE was theoretically analyzed. Firstly, the explicit formula for the mathematical expectation of the FOC-RARE spatial spectrum was derived through the second-order perturbation analysis method. Then, with the assumption that the unexpected modeling errors were drawn from complex circular Gaussian distribution, the theoretical formulas for the angle resolution probability of the FOC-RARE were presented. Numerical experiments validate our analytical results and demonstrate that the FOC-RARE has higher robustness to the unexpected modeling en＇ors than that of the SOS-RARE from the resolution point of view.
文摘Both noise and time delay play important roles in regulating the dynamical behavior in complex systems, such as chemical oscillator, nonlinear circuits, nerve system and networks. It is ever thought that noise can cause breakdown or irregularity of the nonlinear dynamical systems, for example, the thermal noise in circuit could decrease the quality of signals. Indeed, noise often plays a positive role in excitable media; it is found that the regularity can be enhanced under intermediate noise intensi- ty. One distinct example is supported as coherence resonance or stochastic resonance that appropriate noise intensity can en- hance the temporal order, regularity, signal-to-noise ratio （SNR）, and even spatial regularity in network. In theoretical studies, Gaussian white noise, Gaussian colored noise, L（vy noise, and phase noise are often considered in additive or multiplicative type. For biological neurons, channel noise is often considered for transition of electric activities. In the field of pattern selec- tion and control, it is found that noise often cause breakup of target wave and spiral wave, while appropriate noise intensity is important to support the emergence of spiral wave that keeps the network under distinct spatial regularity like a pacemaker.
