To tackle challenges such as interference and poor accuracy of indoor positioning systems,a novel scheme based on ultra-wide bandwidth(UWB)technology is proposed.First,we illustrate a distance measuring method between...To tackle challenges such as interference and poor accuracy of indoor positioning systems,a novel scheme based on ultra-wide bandwidth(UWB)technology is proposed.First,we illustrate a distance measuring method between two UWB devices.Then,a Taylor series expansion algorithm is developed to detect coordinates of the mobile node using the location of anchor nodes and the distance between them.Simulation results show that the observation error under our strategy is within 15 cm,which is superior to existing algorithms.The final experimental data in the hardware system mainly composed of STM32 and DW1000 also confirms the performance of the proposed scheme.展开更多
To solve the precision self-positioning problem for mobile robot,a positioning program based on ultra-wideband technology was proposed. Ultra-wideband pulse has very high bandwidth; ranging accuracy can achieve centim...To solve the precision self-positioning problem for mobile robot,a positioning program based on ultra-wideband technology was proposed. Ultra-wideband pulse has very high bandwidth; ranging accuracy can achieve centimeter-level theoretically. The mobile robot obtained the distance to the reference node by sending ultra-wideband pulse. According to the geometric relations among the references and the robot,establish equations to calculate the position coordinates. Then Kalman filter algorithm was applied for mobile robot tracking. Simulation results show that robot positioning and tracking based on ultra-wideband technology can achieve indoor and outdoor seamless docking.展开更多
In this paper, a compact coplanar epsilon.negative(ENG) antenna is proposed with ultra.wide operation band and small size of 18×11.5 mm2. The proposed antenna is designed based on a coplanar.waveguide(CPW) feedin...In this paper, a compact coplanar epsilon.negative(ENG) antenna is proposed with ultra.wide operation band and small size of 18×11.5 mm2. The proposed antenna is designed based on a coplanar.waveguide(CPW) feeding antenna, and thus the via.free structure is employed to realize the ENG unit cell, which is convenient to tune the frequency of zeroth.order resonance(ZOR) and extends the ZOR bandwidth. The high.order resonant frequencies are achieved and mainly determined by the separate slots that are located between the radiating patch and the ground plane. Adding the left.handed inductance between the radiating patch and ground has slight impact on the high.order resonant frequencies, and then the ultra.wide band is achieved by merging the ZOR bandwidth with the high.order resonant bandwidths. The ground plane primarily works as a matching network for the proposed antenna. Although it generates a low.frequency resonance, the performance is undesirable due to the impedance mismatching. The measured results show that the reflection coefficient, |S11| <.10 d B, is in a wide frequency range from 5.25 to 13 GHz, which covers the upper operation band of UWB communication. Also, the antenna contains relatively stable gains and omni.directional radiation patterns.展开更多
The modern landmine's electronic fuse is susceptible to strong interference or can even be damaged by the ultra-wide band electromagnetic pulse(UWB-EMP). The finite-difference time-domain(FDTD) method in lossy me...The modern landmine's electronic fuse is susceptible to strong interference or can even be damaged by the ultra-wide band electromagnetic pulse(UWB-EMP). The finite-difference time-domain(FDTD) method in lossy media with cylindrical coordinates is used to study the interactions of the UWB-EMP with the landmine. First, the coupling of UWB-EMP into the landmine shielding shell through an aperture is numerically simulated. Second, the coupled electromagnetic field of mine shells made of different shielding materials and with apertures of different sizes is plotted. Third, the aperture coupling laws of UWB-EMP into shells are analyzed and categorized. Such an algorithm is capable of effectively preventing ladder similar errors, and consequently improving the calculation precision, and in addition to adopting the message passing interface(MPI) parallel method to divide the total calculating range into more sub-ranges, the overall calculating efficiency is greatly increased. These calculations are surely a constructive reference for modern landmine design against electromagnetic damage.展开更多
Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications...Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications. In this paper, we have designed a field-effect transistor based on carbon nanotube with high transition frequency suitable for ultra-wide band applications. We did this by optimizing nanotube diameter, gate insulator thickness and dielectric constant. As a result, we achieved the transition frequency about 7.45 THz. The environment of open source software FETToy is used to simulate the device. Also a suitable model for calculating the transition frequency is presented.展开更多
The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the ...The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the multipath fading model is assumed in this scenario. In fact to establish the model for analyzing in this article is using MC-CDMA (multi-carrier code-division multiple-access) system characterization combined with a UWB scheme. The average BER (bit error rate) is calculated and compared to a special case of previously published results. Studied results from this paper can be implied to approve the system performance for a UWB system combined with a MC-CDMA wireless communication system. It is worth noting that the Nakagami-m distributed fading parameter significantly dominates UWB system performance when it cooperates with MC signaling under a fading environment. Finally, it is worthy of noting that when the SNR (signal-to-noise ratio) at system’s receiver reaches a preset high threshold value, the parameter of power decay ratio effect could be not included.展开更多
Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded p...Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.展开更多
随着无线电通信的迅速发展,频谱资源日益紧张,各种干扰问题也越来越严重。其中,900 M Hz频段的干扰问题尤为突出。该文提出了一种基于信号特征分析和机器学习技术的900 MHz频段干扰自动定位方法,通过对干扰信号的频谱、时域、调制等特...随着无线电通信的迅速发展,频谱资源日益紧张,各种干扰问题也越来越严重。其中,900 M Hz频段的干扰问题尤为突出。该文提出了一种基于信号特征分析和机器学习技术的900 MHz频段干扰自动定位方法,通过对干扰信号的频谱、时域、调制等特征进行分析,建立干扰信号特征库,并利用机器学习算法对信号进行分类和定位。实验结果表明,该文提出的方法具有较高的干扰定位准确率和稳定性,能够有效地提高频谱资源利用效率的闭环。展开更多
基金National Key Research and Development Program of China,No.2018YFC0604404.
文摘To tackle challenges such as interference and poor accuracy of indoor positioning systems,a novel scheme based on ultra-wide bandwidth(UWB)technology is proposed.First,we illustrate a distance measuring method between two UWB devices.Then,a Taylor series expansion algorithm is developed to detect coordinates of the mobile node using the location of anchor nodes and the distance between them.Simulation results show that the observation error under our strategy is within 15 cm,which is superior to existing algorithms.The final experimental data in the hardware system mainly composed of STM32 and DW1000 also confirms the performance of the proposed scheme.
基金High Technology Research and Development Program(863program) of China (No.2007AA041604)
文摘To solve the precision self-positioning problem for mobile robot,a positioning program based on ultra-wideband technology was proposed. Ultra-wideband pulse has very high bandwidth; ranging accuracy can achieve centimeter-level theoretically. The mobile robot obtained the distance to the reference node by sending ultra-wideband pulse. According to the geometric relations among the references and the robot,establish equations to calculate the position coordinates. Then Kalman filter algorithm was applied for mobile robot tracking. Simulation results show that robot positioning and tracking based on ultra-wideband technology can achieve indoor and outdoor seamless docking.
基金supported by the National Natural Science Foundation of China (NNSF) under Grant 61531016National Natural Science Foundation of China (NNSF) under Grant 61271090+1 种基金Sichuan province science and technology support project under Grant 2016GZ0059Sichuan province science and technology support project under Grant 2017GZ0110
文摘In this paper, a compact coplanar epsilon.negative(ENG) antenna is proposed with ultra.wide operation band and small size of 18×11.5 mm2. The proposed antenna is designed based on a coplanar.waveguide(CPW) feeding antenna, and thus the via.free structure is employed to realize the ENG unit cell, which is convenient to tune the frequency of zeroth.order resonance(ZOR) and extends the ZOR bandwidth. The high.order resonant frequencies are achieved and mainly determined by the separate slots that are located between the radiating patch and the ground plane. Adding the left.handed inductance between the radiating patch and ground has slight impact on the high.order resonant frequencies, and then the ultra.wide band is achieved by merging the ZOR bandwidth with the high.order resonant bandwidths. The ground plane primarily works as a matching network for the proposed antenna. Although it generates a low.frequency resonance, the performance is undesirable due to the impedance mismatching. The measured results show that the reflection coefficient, |S11| <.10 d B, is in a wide frequency range from 5.25 to 13 GHz, which covers the upper operation band of UWB communication. Also, the antenna contains relatively stable gains and omni.directional radiation patterns.
基金Project supported by the Postdoctoral Science Foundation of China(Grant No.2014M552610)
文摘The modern landmine's electronic fuse is susceptible to strong interference or can even be damaged by the ultra-wide band electromagnetic pulse(UWB-EMP). The finite-difference time-domain(FDTD) method in lossy media with cylindrical coordinates is used to study the interactions of the UWB-EMP with the landmine. First, the coupling of UWB-EMP into the landmine shielding shell through an aperture is numerically simulated. Second, the coupled electromagnetic field of mine shells made of different shielding materials and with apertures of different sizes is plotted. Third, the aperture coupling laws of UWB-EMP into shells are analyzed and categorized. Such an algorithm is capable of effectively preventing ladder similar errors, and consequently improving the calculation precision, and in addition to adopting the message passing interface(MPI) parallel method to divide the total calculating range into more sub-ranges, the overall calculating efficiency is greatly increased. These calculations are surely a constructive reference for modern landmine design against electromagnetic damage.
文摘Theoretical calculations predict transition frequencies in the terahertz range for the field-effect transistors based on carbon nanotubes, and this shows their suitability for being used in high frequency applications. In this paper, we have designed a field-effect transistor based on carbon nanotube with high transition frequency suitable for ultra-wide band applications. We did this by optimizing nanotube diameter, gate insulator thickness and dielectric constant. As a result, we achieved the transition frequency about 7.45 THz. The environment of open source software FETToy is used to simulate the device. Also a suitable model for calculating the transition frequency is presented.
文摘The evaluation of System Performance of UWB (ultra-wide band) jointing in MC (multi-carrier) signaling in correlated environments is presented in the report. The correlated Nakagami-m statistical distribution for the multipath fading model is assumed in this scenario. In fact to establish the model for analyzing in this article is using MC-CDMA (multi-carrier code-division multiple-access) system characterization combined with a UWB scheme. The average BER (bit error rate) is calculated and compared to a special case of previously published results. Studied results from this paper can be implied to approve the system performance for a UWB system combined with a MC-CDMA wireless communication system. It is worth noting that the Nakagami-m distributed fading parameter significantly dominates UWB system performance when it cooperates with MC signaling under a fading environment. Finally, it is worthy of noting that when the SNR (signal-to-noise ratio) at system’s receiver reaches a preset high threshold value, the parameter of power decay ratio effect could be not included.
文摘Using an improved particle swarm optimization algorithm(IPSO)to drive a transfer matrix method,a nonreciprocal absorber with an ultrawide absorption bandwidth and angular insensitivity is realized in plasma-embedded photonic crystals arranged in a structure composed of periodic and quasi-periodic sequences on a normalized scale.The effective dielectric function,which determines the absorption of the plasma,is subject to the basic parameters of the plasma,causing the absorption of the proposed absorber to be easily modulated by these parameters.Compared with other quasi-periodic sequences,the Octonacci sequence is superior both in relative bandwidth and absolute bandwidth.Under further optimization using IPSO with 14 parameters set to be optimized,the absorption characteristics of the proposed structure with different numbers of layers of the smallest structure unit N are shown and discussed.IPSO is also used to address angular insensitive nonreciprocal ultrawide bandwidth absorption,and the optimized result shows excellent unidirectional absorbability and angular insensitivity of the proposed structure.The impacts of the sequence number of quasi-periodic sequence M and collision frequency of plasma1ν1 to absorption in the angle domain and frequency domain are investigated.Additionally,the impedance match theory and the interference field theory are introduced to express the findings of the algorithm.
文摘随着无线电通信的迅速发展,频谱资源日益紧张,各种干扰问题也越来越严重。其中,900 M Hz频段的干扰问题尤为突出。该文提出了一种基于信号特征分析和机器学习技术的900 MHz频段干扰自动定位方法,通过对干扰信号的频谱、时域、调制等特征进行分析,建立干扰信号特征库,并利用机器学习算法对信号进行分类和定位。实验结果表明,该文提出的方法具有较高的干扰定位准确率和稳定性,能够有效地提高频谱资源利用效率的闭环。