This paper presents a joint high order statistics （HOS） and signal-to-noise ratio （SNR） algorithm for the recognition of multiple-input multiple-output （MIMO） radar signal without a priori knowledge of the signa...This paper presents a joint high order statistics （HOS） and signal-to-noise ratio （SNR） algorithm for the recognition of multiple-input multiple-output （MIMO） radar signal without a priori knowledge of the signal parameters. This method is capable of recognizing the MIMO radar signal as well as discriminating it from single-carrier signal adopted by conventional radar. Meanwhile, the sub-carrier number of the none-coding MIMO radar signal is estimated. Extensive simulations are carried out in different operating conditions. Simulation results prove the feasibility and indicate that the recognition probability could reach over 90% when the value of SNR is above 0 dB.展开更多
针对微机电系统(MEMS)陀螺存在的非线性、非平稳噪声,提出了应用经验模态分解/高阶统计(EMD-HOS)的降噪方法对MEMS陀螺进行降噪。首先,采集MEMS陀螺输出信号,根据EMD算法将信号分解成本征模态函数(IMF)。采用Bootstrap技术分别估计各IM...针对微机电系统(MEMS)陀螺存在的非线性、非平稳噪声,提出了应用经验模态分解/高阶统计(EMD-HOS)的降噪方法对MEMS陀螺进行降噪。首先,采集MEMS陀螺输出信号,根据EMD算法将信号分解成本征模态函数(IMF)。采用Bootstrap技术分别估计各IMF的峰度值,进行高斯特性检验,滤除高斯IMF。接着,使用方差聚合法分别计算IMF的Hurst指数,根据Hurst指数计算阈值,对各IMF进行软阈值处理。将阈值处理后的剩余IMF进行重构,达到降噪的目的。最后,通过交叠式Allan方差分析对滤波前后数据进行处理,绘制Allan方差与相关时间关系曲线,利用非线性最小二乘拟合方法,计算陀螺噪声各项指标。实验表明,EMD-HOS和软阈值处理能够有效地对MEMS陀螺降噪,其信噪比提高了5.6 d B,各项陀螺随机噪声关键指标提高近一个量级。展开更多
An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （S...An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （STFT） domain. After analyzing the instan- taneous frequency and instantaneous bandwidth to deduce the relation between the window length and deviation of the Gaus- sian window, high-order statistics is used to select the appropriate window length for STFT and get the optimal SNR with the right time-frequency resolution according to the signal characteristic under a fixed sampling rate. Computer simulations have verified the effectiveness of the new method.展开更多
文摘提出一种基于符号高阶统计量(HOS,high-order statistics)的MPSK调制信道衰落系数盲估计算法。针对平坦慢衰落信道模型,首先分析了MPSK调制符号高阶统计量特征,证明了MPSK调制符号的M次方符号的值是唯一的,而当1≤M′<M时,调制符号的M′次方符号在复平面上是对称分布的;之后利用此特征推导出MPSK调制阶数、初始相位和衰落系数估计算法。仿真实验表明,信噪比高于12 d B条件下,HOS算法估计性能与目前平坦慢衰落信道盲估计的主流方法 Lloyd-Max算法相同,而算法复杂度为Lloyd-Max算法的1/50,并且在接收样本符号较少的条件下HOS算法的均方误差曲线收敛于最小二乘估计理论下界。
基金supported by the Foundation of Chinese People’s Liberation Army General Equipment Department(41101020303)
文摘This paper presents a joint high order statistics （HOS） and signal-to-noise ratio （SNR） algorithm for the recognition of multiple-input multiple-output （MIMO） radar signal without a priori knowledge of the signal parameters. This method is capable of recognizing the MIMO radar signal as well as discriminating it from single-carrier signal adopted by conventional radar. Meanwhile, the sub-carrier number of the none-coding MIMO radar signal is estimated. Extensive simulations are carried out in different operating conditions. Simulation results prove the feasibility and indicate that the recognition probability could reach over 90% when the value of SNR is above 0 dB.
文摘针对微机电系统(MEMS)陀螺存在的非线性、非平稳噪声,提出了应用经验模态分解/高阶统计(EMD-HOS)的降噪方法对MEMS陀螺进行降噪。首先,采集MEMS陀螺输出信号,根据EMD算法将信号分解成本征模态函数(IMF)。采用Bootstrap技术分别估计各IMF的峰度值,进行高斯特性检验,滤除高斯IMF。接着,使用方差聚合法分别计算IMF的Hurst指数,根据Hurst指数计算阈值,对各IMF进行软阈值处理。将阈值处理后的剩余IMF进行重构,达到降噪的目的。最后,通过交叠式Allan方差分析对滤波前后数据进行处理,绘制Allan方差与相关时间关系曲线,利用非线性最小二乘拟合方法,计算陀螺噪声各项指标。实验表明,EMD-HOS和软阈值处理能够有效地对MEMS陀螺降噪,其信噪比提高了5.6 d B,各项陀螺随机噪声关键指标提高近一个量级。
基金supported by the National Natural Science Foundation of China(6107313361175053+8 种基金6127236960975019)the Heilongjiang Postdoctoral Grant(LRB08362)the Fundamental Research Funds for the Central Universities of China(2011QN0272011QN1262012QN0302011ZD010)the Science and Technology Planning Project of Dalian City(2011A17GX0732010E15SF153)
文摘An adaptive approach to select analysis window param- eters for linear frequency modulated （LFM） signals is proposed to obtain the optimal 3 dB signal-to-noise ratio （SNR） in the short- time Fourier transform （STFT） domain. After analyzing the instan- taneous frequency and instantaneous bandwidth to deduce the relation between the window length and deviation of the Gaus- sian window, high-order statistics is used to select the appropriate window length for STFT and get the optimal SNR with the right time-frequency resolution according to the signal characteristic under a fixed sampling rate. Computer simulations have verified the effectiveness of the new method.
