绝缘油是电抗器内部重要的绝缘介质,击穿电压是评估其绝缘特性的关键指标,与绝缘油的品质状态密切相关。本文共选取155组电抗器绝缘油进行实验,分别进行击穿电压的测定和多频超声信号在油样中传播衰减后信号的采集,分析多频超声声学参...绝缘油是电抗器内部重要的绝缘介质,击穿电压是评估其绝缘特性的关键指标,与绝缘油的品质状态密切相关。本文共选取155组电抗器绝缘油进行实验,分别进行击穿电压的测定和多频超声信号在油样中传播衰减后信号的采集,分析多频超声声学参数和击穿电压之间的幅频响应、相频响应之间的关系,并基于多频超声检测技术提出结合灰狼优化算法(grey wolf optimizer,GWO)优化随机森林算法(random forest algorithm,RF)的击穿电压预测方法。结果表明:GWO-RF绝缘油击穿电压预测模型的预测值与实际值的平均相对误差为4.04%,预测准确率达到95.96%,相较于优化前的RF绝缘油击穿电压预测模型准确率提升了20.25%。结合多频超声检测技术和GWO-RF建立的并联电抗器绝缘油击穿电压预测模型,对击穿电压的预测具有可行性。展开更多
This paper investigates how to achieve integrated sensing and communication(ISAC)based on a cell-free radio access network(CF-RAN)architecture with a minimum footprint of communication resources.We propose a new passi...This paper investigates how to achieve integrated sensing and communication(ISAC)based on a cell-free radio access network(CF-RAN)architecture with a minimum footprint of communication resources.We propose a new passive sensing scheme.The scheme is based on the radio frequency(RF)fingerprint learning of the RF radio unit(RRU)to build an RF fingerprint library of RRUs.The source RRU is identified by comparing the RF fingerprints carried by the signal at the receiver side.The receiver extracts the channel parameters from the signal and estimates the channel environment,thus locating the reflectors in the environment.The proposed scheme can effectively solve the problem of interference between signals in the same time-frequency domain but in different spatial domains when multiple RRUs jointly serve users in CF-RAN architecture.Simulation results show that the proposed passive ISAC scheme can effectively detect reflector location information in the environment without degrading the communication performance.展开更多
针对现有低功耗蓝牙(BLE)欺骗攻击检测技术准确率低的问题,提出了一种基于异常指纹的BLE欺骗攻击检测技术,将攻击者的射频指纹作为异常数据,把欺骗攻击检测建模为异常检测问题;设计了一种基于深度支持向量描述(Deep Support Vector Data...针对现有低功耗蓝牙(BLE)欺骗攻击检测技术准确率低的问题,提出了一种基于异常指纹的BLE欺骗攻击检测技术,将攻击者的射频指纹作为异常数据,把欺骗攻击检测建模为异常检测问题;设计了一种基于深度支持向量描述(Deep Support Vector Data Description,DeepSVDD)的异常指纹检测模型——RFFAD_DeepSVDD,并使用残差单元构建网络模型,有效缓解了机器学习异常检测算法非线性特征提取不足的问题。采用预训练自编码器获取最优初始化参数,极大增强了模型边界决策能力。在异常检测实验中,该模型准确率达到95.47%,相比基于机器学习的异常检测模型平均提升8.92%;在欺骗攻击检测实验中,该方法相比现有欺骗攻击检测技术在攻击节点运动与静止状态下均表现出更好的性能,能够准确检测并识别出中间人攻击、冒充攻击、重连接欺骗攻击3种欺骗攻击。展开更多
With the development of wireless communication technology,an urgent problem to be solved is co-site broadband interference on independent communication platforms such as satellites,space stations,aircrafts and ships.A...With the development of wireless communication technology,an urgent problem to be solved is co-site broadband interference on independent communication platforms such as satellites,space stations,aircrafts and ships.Also,the problem of strong selfinterference rejection should be solved in the co-time co-frequency full duplex mode which realizes spectrum multiplication in 5G communication technology.In the research of such interference rejection,interference cancellation technology has been applied.In order to reject multipath interference,multitap double LMS(Least Mean Square)loop interference cancellation system is often used for cancelling RF(Radio Frequency)domain interference cancelling.However,more taps will lead to a more complex structure of the cancellation system.A novel tap single LMS loop adaptive interference cancellation system was proposed to improve the system compactness and reduce the cost.In addition,a mathematical model was built for the proposed cancellation system,the correlation function of CP2FSK(Continuous Phase Binary Frequency Shift Keying)signal was derived,and the quantitative relationship was established between the correlation function and the interference signal bandwidth and tap delay differential.The steadystate weights and the expression of the average interference cancellation ratio(ICR)were deduced in the scenes of LOS(Line of Sight)interference with antenna swaying on an independent communication platform and indoor multipath interference.The quantitative relationship was deeply analyzed between the interference cancellation performance and the parameters such as antenna swing,LMS loop gain,and interference signal bandwidth,which was verified by simulation experiment.And the performance of the proposed interference cancellation system was compared with that of the traditional double LMS loop cancellation system.The results showed that the compact single LMS loop cancellation system can achieve an average interference rejection capability comparable to the double LMS loop cancellation system.展开更多
文摘绝缘油是电抗器内部重要的绝缘介质,击穿电压是评估其绝缘特性的关键指标,与绝缘油的品质状态密切相关。本文共选取155组电抗器绝缘油进行实验,分别进行击穿电压的测定和多频超声信号在油样中传播衰减后信号的采集,分析多频超声声学参数和击穿电压之间的幅频响应、相频响应之间的关系,并基于多频超声检测技术提出结合灰狼优化算法(grey wolf optimizer,GWO)优化随机森林算法(random forest algorithm,RF)的击穿电压预测方法。结果表明:GWO-RF绝缘油击穿电压预测模型的预测值与实际值的平均相对误差为4.04%,预测准确率达到95.96%,相较于优化前的RF绝缘油击穿电压预测模型准确率提升了20.25%。结合多频超声检测技术和GWO-RF建立的并联电抗器绝缘油击穿电压预测模型,对击穿电压的预测具有可行性。
基金supported in part by the National Key Research and Development Program under Grant(2021YFB2900300)by the National Natural Science Foundation of China(NSFC)under Grants 61971127,61871122by the Southeast University-China Mobile Research Institute Joint Innovation Center,and by the Major Key Project of PCL(PCL2021A01-2).
文摘This paper investigates how to achieve integrated sensing and communication(ISAC)based on a cell-free radio access network(CF-RAN)architecture with a minimum footprint of communication resources.We propose a new passive sensing scheme.The scheme is based on the radio frequency(RF)fingerprint learning of the RF radio unit(RRU)to build an RF fingerprint library of RRUs.The source RRU is identified by comparing the RF fingerprints carried by the signal at the receiver side.The receiver extracts the channel parameters from the signal and estimates the channel environment,thus locating the reflectors in the environment.The proposed scheme can effectively solve the problem of interference between signals in the same time-frequency domain but in different spatial domains when multiple RRUs jointly serve users in CF-RAN architecture.Simulation results show that the proposed passive ISAC scheme can effectively detect reflector location information in the environment without degrading the communication performance.
文摘针对现有低功耗蓝牙(BLE)欺骗攻击检测技术准确率低的问题,提出了一种基于异常指纹的BLE欺骗攻击检测技术,将攻击者的射频指纹作为异常数据,把欺骗攻击检测建模为异常检测问题;设计了一种基于深度支持向量描述(Deep Support Vector Data Description,DeepSVDD)的异常指纹检测模型——RFFAD_DeepSVDD,并使用残差单元构建网络模型,有效缓解了机器学习异常检测算法非线性特征提取不足的问题。采用预训练自编码器获取最优初始化参数,极大增强了模型边界决策能力。在异常检测实验中,该模型准确率达到95.47%,相比基于机器学习的异常检测模型平均提升8.92%;在欺骗攻击检测实验中,该方法相比现有欺骗攻击检测技术在攻击节点运动与静止状态下均表现出更好的性能,能够准确检测并识别出中间人攻击、冒充攻击、重连接欺骗攻击3种欺骗攻击。
基金supported by the National Natural Science Foundation of China[Grant No.61771187]the Natural Science Foundation of Hubei Province[Grant No.2016CFB396]+1 种基金the Hubei Provincial Technology Innovation Special Major Project[Grant No.2019AAA018]the Major Project of Hubei Collaborative Innovation Center for High-efficiency Utilization of Solar Energy[HBSKFZD2015002]。
文摘With the development of wireless communication technology,an urgent problem to be solved is co-site broadband interference on independent communication platforms such as satellites,space stations,aircrafts and ships.Also,the problem of strong selfinterference rejection should be solved in the co-time co-frequency full duplex mode which realizes spectrum multiplication in 5G communication technology.In the research of such interference rejection,interference cancellation technology has been applied.In order to reject multipath interference,multitap double LMS(Least Mean Square)loop interference cancellation system is often used for cancelling RF(Radio Frequency)domain interference cancelling.However,more taps will lead to a more complex structure of the cancellation system.A novel tap single LMS loop adaptive interference cancellation system was proposed to improve the system compactness and reduce the cost.In addition,a mathematical model was built for the proposed cancellation system,the correlation function of CP2FSK(Continuous Phase Binary Frequency Shift Keying)signal was derived,and the quantitative relationship was established between the correlation function and the interference signal bandwidth and tap delay differential.The steadystate weights and the expression of the average interference cancellation ratio(ICR)were deduced in the scenes of LOS(Line of Sight)interference with antenna swaying on an independent communication platform and indoor multipath interference.The quantitative relationship was deeply analyzed between the interference cancellation performance and the parameters such as antenna swing,LMS loop gain,and interference signal bandwidth,which was verified by simulation experiment.And the performance of the proposed interference cancellation system was compared with that of the traditional double LMS loop cancellation system.The results showed that the compact single LMS loop cancellation system can achieve an average interference rejection capability comparable to the double LMS loop cancellation system.
