Intra-pulse characteristics of different radar emitter signals reflect on signal waveform by way of changing frequency, phase and amplitude. A novel approach was proposed to extract complexity features of radar emitte...Intra-pulse characteristics of different radar emitter signals reflect on signal waveform by way of changing frequency, phase and amplitude. A novel approach was proposed to extract complexity features of radar emitter signals in a wide range of signal-to-noise ratio (SNR), and radial basis probability neural network (RBPNN) was used to recognize different radar emitter signals. Complexity features, including Lempel-Ziv complexity (LZC) and correlation dimension (CD), can measure the complexity and irregularity of signals, which mirrors the intra-pulse modulation laws of radar emitter signals. In an experiment, LZC and CD features of 10 typical radar emitter signals were extracted and RBPNN was applied to identify the 10 radar emitter signals. Simulation results show that the proposed approach is effective and has good application values because average accurate recognition rate is high when SNR varies in a wide range.展开更多
This paper presents a novel method for radar emitter signal recognition. First, wavelet packet transform （WPT） is introduced to extract features from radar emitter signals. Then, rough set theory is used to select t...This paper presents a novel method for radar emitter signal recognition. First, wavelet packet transform （WPT） is introduced to extract features from radar emitter signals. Then, rough set theory is used to select the optimal feature subset with good discriminability from original feature set, and support vector machines （SVMs） are employed to design classifiers. A large number of experimental results show that the proposed method achieves very high recognition rates for 9 radar emitter signals in a wide range of signal-to-noise rates, and proves a feasible and valid method.展开更多
模糊函数主脊(Ambiguity function main ridge,AFMR)切面特征能较好地反映不同信号结构上的本质差别,是解决当前复杂体制雷达辐射源信号分选难题的可行参数,而快速、智能地搜索模糊函数主脊切面是增加其切面特征实用性的重要问题。为此...模糊函数主脊(Ambiguity function main ridge,AFMR)切面特征能较好地反映不同信号结构上的本质差别,是解决当前复杂体制雷达辐射源信号分选难题的可行参数,而快速、智能地搜索模糊函数主脊切面是增加其切面特征实用性的重要问题。为此,本文构建了一种结合均匀初始化策略和改进非线性收敛因子的改进自适应灰狼算法来搜索典型6种雷达辐射源信号的模糊函数主脊切面并提取切面特征,并与穷举法和标准灰狼算法进行对比。实验结果表明,所提方法在搜索AFMR切面并提取特征时,平均耗时仅为1.49 s,相较于穷举法和标准灰狼优化算法,效率分别提高了75.7%和19.0%,具有较优的时效性。在固定信噪比(Signal⁃to⁃noise ratio,SNR)环境下,当SNR不低于0 dB时,提取到特征值的平均聚类准确率为96.4%,在0~20 dB动态信噪比环境下,平均聚类准确率可达95.2%,具有较好的准确性、抗噪性能及较强的类内聚集性和类间分离能力,证实了所提方法的可行性与有效性。展开更多
随着现代技术不断更新,雷达种类及相关技术得到不断发展,雷达辐射源信号的识别逐渐成为一个十分重要的研究领域。该文主要针对辐射源信号识别中的调制类型识别问题,从数据能量角度出发,在奇异值分解(Singular Value Decomposition, SVD...随着现代技术不断更新,雷达种类及相关技术得到不断发展,雷达辐射源信号的识别逐渐成为一个十分重要的研究领域。该文主要针对辐射源信号识别中的调制类型识别问题,从数据能量角度出发,在奇异值分解(Singular Value Decomposition, SVD)基础上进行优化,提出基于权重归一化奇异值分解特征提取算法。该文从奇异值分解的滤波效果、数据矩阵行数对分解结果的影响及不同分类模型识别效果等方面进行分析。实验结果表明该算法对常用雷达信号有较好滤波和识别效果,在–20 dB条件下滤波重构信号与原始信号余弦相似度值仍保持在0.94左右,在判别置信度?为0.65条件下识别正确率仍维持在97%以上。此外实验还表明相对于传统PCA算法,基于权重归一化奇异值分解特征提取算法拥有更好的鲁棒性。展开更多
基金TheNationalDefenceFoundation (No .NEWL5 14 35QT2 2 0 4 0 1) ,theDoctoralInnovationFoundationofSWJTU ,andtheMainTeacherSponsorProgramoftheMinistryofEducationofChina (No .6 5 ,2 0 0 0 )
文摘Intra-pulse characteristics of different radar emitter signals reflect on signal waveform by way of changing frequency, phase and amplitude. A novel approach was proposed to extract complexity features of radar emitter signals in a wide range of signal-to-noise ratio (SNR), and radial basis probability neural network (RBPNN) was used to recognize different radar emitter signals. Complexity features, including Lempel-Ziv complexity (LZC) and correlation dimension (CD), can measure the complexity and irregularity of signals, which mirrors the intra-pulse modulation laws of radar emitter signals. In an experiment, LZC and CD features of 10 typical radar emitter signals were extracted and RBPNN was applied to identify the 10 radar emitter signals. Simulation results show that the proposed approach is effective and has good application values because average accurate recognition rate is high when SNR varies in a wide range.
文摘This paper presents a novel method for radar emitter signal recognition. First, wavelet packet transform （WPT） is introduced to extract features from radar emitter signals. Then, rough set theory is used to select the optimal feature subset with good discriminability from original feature set, and support vector machines （SVMs） are employed to design classifiers. A large number of experimental results show that the proposed method achieves very high recognition rates for 9 radar emitter signals in a wide range of signal-to-noise rates, and proves a feasible and valid method.
文摘模糊函数主脊(Ambiguity function main ridge,AFMR)切面特征能较好地反映不同信号结构上的本质差别,是解决当前复杂体制雷达辐射源信号分选难题的可行参数,而快速、智能地搜索模糊函数主脊切面是增加其切面特征实用性的重要问题。为此,本文构建了一种结合均匀初始化策略和改进非线性收敛因子的改进自适应灰狼算法来搜索典型6种雷达辐射源信号的模糊函数主脊切面并提取切面特征,并与穷举法和标准灰狼算法进行对比。实验结果表明,所提方法在搜索AFMR切面并提取特征时,平均耗时仅为1.49 s,相较于穷举法和标准灰狼优化算法,效率分别提高了75.7%和19.0%,具有较优的时效性。在固定信噪比(Signal⁃to⁃noise ratio,SNR)环境下,当SNR不低于0 dB时,提取到特征值的平均聚类准确率为96.4%,在0~20 dB动态信噪比环境下,平均聚类准确率可达95.2%,具有较好的准确性、抗噪性能及较强的类内聚集性和类间分离能力,证实了所提方法的可行性与有效性。
文摘针对传统的雷达辐射源信号识别方法在低信噪比环境下的正确率较低,且通常只适用几种特定的雷达信号的问题,提出一种基于距离特征的辐射源信号识别方法。使用k-means算法提取若干个聚类中心,分别计算雷达信号脉冲与聚类中心之间的DTW (Dynamic Time Warping)度量值,联合这些度量值作为k邻近算法的输入进行识别。仿真结果表明,在信噪比为3d B时,所提方法对6类雷达信号的识别率达到91%。与基于小波脊频级联特征的方法相比,所提方法也表现出更好的识别效果。
文摘随着现代技术不断更新,雷达种类及相关技术得到不断发展,雷达辐射源信号的识别逐渐成为一个十分重要的研究领域。该文主要针对辐射源信号识别中的调制类型识别问题,从数据能量角度出发,在奇异值分解(Singular Value Decomposition, SVD)基础上进行优化,提出基于权重归一化奇异值分解特征提取算法。该文从奇异值分解的滤波效果、数据矩阵行数对分解结果的影响及不同分类模型识别效果等方面进行分析。实验结果表明该算法对常用雷达信号有较好滤波和识别效果,在–20 dB条件下滤波重构信号与原始信号余弦相似度值仍保持在0.94左右,在判别置信度?为0.65条件下识别正确率仍维持在97%以上。此外实验还表明相对于传统PCA算法,基于权重归一化奇异值分解特征提取算法拥有更好的鲁棒性。
