To deal with the non-Caussian noise in standard 2-D SAR images, the deramped signal in imaging plane, and the possible symmetric distribution of complex noise, the fourth-order cumulant of complex process is introduce...To deal with the non-Caussian noise in standard 2-D SAR images, the deramped signal in imaging plane, and the possible symmetric distribution of complex noise, the fourth-order cumulant of complex process is introduced into SAR tomography. With the estimated AR parameters of ARMA model of noise through Yule-Walker equation, the signal series of height is pre-filtered. Then, through ESPRIT, the spectrum is obtained and the aperture in height direction is synthesized. Finally, the SAR tomography imaging of scene is achieved. The results of processing on signal with non-Gaussian noise demonstrate the robustness of the proposed method. The tomography imaging of the scenes shows that the higher-order spectrum analysis is feasible in the application.展开更多
为了识别当前通信系统所采用的主要调制方式,该文结合高阶累积量和循环谱的特点,采用混合识别算法,同时应用智能决策算法(神经网络)对信号进行识别。该算法基于四阶和六阶高阶累积量构造出一个新的特征参数,将数字调制信号分为{BPSK,2AS...为了识别当前通信系统所采用的主要调制方式,该文结合高阶累积量和循环谱的特点,采用混合识别算法,同时应用智能决策算法(神经网络)对信号进行识别。该算法基于四阶和六阶高阶累积量构造出一个新的特征参数,将数字调制信号分为{BPSK,2ASK},{QPSK},{2FSK,4FSK},{MSK}和{16QAM,64QAM}5类。然后利用高阶累积量的其它特征参数以及循环谱特征对{OFDM},{16QAM,64QAM},{2ASK,BPSK}及{2FSK,4FSK}进行识别。为便于工程实现,该文采用半实物仿真以及Lab VIEW和MATLAB混合编程来验证算法。仿真结果证明,该算法能够在较低信噪比下实现对{OFDM,BPSK,QPSK,2ASK,2FSK,4FSK,MSK,16QAM,64QAM}等多种信号的分类,在信噪比高于5 d B时,调制方式识别率可达94%以上,由此证明了该方法的有效性。展开更多
基金supported partly by the New Century Excellent Talents in University(23901019)the Sichuan Provincial Youth Science and Technology Foundation(06ZQ026-006).
文摘To deal with the non-Caussian noise in standard 2-D SAR images, the deramped signal in imaging plane, and the possible symmetric distribution of complex noise, the fourth-order cumulant of complex process is introduced into SAR tomography. With the estimated AR parameters of ARMA model of noise through Yule-Walker equation, the signal series of height is pre-filtered. Then, through ESPRIT, the spectrum is obtained and the aperture in height direction is synthesized. Finally, the SAR tomography imaging of scene is achieved. The results of processing on signal with non-Gaussian noise demonstrate the robustness of the proposed method. The tomography imaging of the scenes shows that the higher-order spectrum analysis is feasible in the application.
文摘为了识别当前通信系统所采用的主要调制方式,该文结合高阶累积量和循环谱的特点,采用混合识别算法,同时应用智能决策算法(神经网络)对信号进行识别。该算法基于四阶和六阶高阶累积量构造出一个新的特征参数,将数字调制信号分为{BPSK,2ASK},{QPSK},{2FSK,4FSK},{MSK}和{16QAM,64QAM}5类。然后利用高阶累积量的其它特征参数以及循环谱特征对{OFDM},{16QAM,64QAM},{2ASK,BPSK}及{2FSK,4FSK}进行识别。为便于工程实现,该文采用半实物仿真以及Lab VIEW和MATLAB混合编程来验证算法。仿真结果证明,该算法能够在较低信噪比下实现对{OFDM,BPSK,QPSK,2ASK,2FSK,4FSK,MSK,16QAM,64QAM}等多种信号的分类,在信噪比高于5 d B时,调制方式识别率可达94%以上,由此证明了该方法的有效性。
