A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time ...A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time beam scanning by reconfiguring the phase of an antenna unit.The unit,designed at 28 GHz using a simple patch structure with one PIN diode,can be electronically controlled to generate 1 bit phase quantization.A prototype of the antenna is fabricated and measured to demonstrate the feasibility of this approach.The measurement results indicate that the antenna achieves high gain and fast beam-steering,with the scan beams within±60°range and the maximum gain up to 21.7 dBi.Furthermore,it is also tested for wireless video transmission.In ZTE Shanghai,the antenna was used for the 5G New Radio(NR)test.The error vector magnitude(EVM)is less than 3%and the adjacent channel leakage ratio(ACLR)less than−35 dBc,which can meet 5G system requirements.Compared with the conventional phased array antenna,the proposed phased array has the advantages of low power consumption,low cost and conformal geometry.Due to these characteristics,the antenna is promising for wide applications in 5G millimeter-wave communication systems.展开更多
Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed fil...Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed filtennas are achieved by combining the predesigned compact 5G(5.975–7.125 GHz)third-order uniform and non-uniform transmission line hairpin bandpass filters(UTL and NTL HPBFs)with the compact ultrawide band Vivaldi tapered slot antenna(UWB VTSA)in one module.The objective of this integration is to enhance the performance of 5.975–7.125GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA.Based on NTL HPBF,more space is provided to add the direct current(DC)biassing circuits in cognitive radio networks(CRNs)for frequency reconfigurable applications.To overcome the mismatch between HPBFs and VTSA,detailed parametric studies are presented.Computer simulation technology(CST)software is used for the simulation in this study.Good measured S11 appeared to be<−13 and<−10.54 dB at 5.48–7.73 and 5.9–7.98GHz with peak realized gains of 6.37 and 6.27 dBi,for VTSA with UTL and NTL HPBFs,respectively which outperforms the predesigned filters.Validation is carried out by comparing the measured and simulated results.展开更多
The application of information and communications technology(ICT)in the education industry is becoming more and more extensive,and online education realized through ICT is developing in full swing.The influence of ICT...The application of information and communications technology(ICT)in the education industry is becoming more and more extensive,and online education realized through ICT is developing in full swing.The influence of ICT on online education consumer's choice behavior is the core issue of online education industry development research.The research on the interactive path and methods of information and online education consumer choice behavior is worth exploring and revealing.This study introduces the word-of-mouth factor as a new research variable under the framework of the Rational Choice Theory model(RCT)and the structural equation method to conduct empirical research and theoretical analysis to verify the validity of the hypothesis and model.The fifthGeneration mobile communication system(5 G)analyses the factors affecting online education consumer behavior choices based on the premise of ICT.Research on the path between ICT and choice behavior provides new ideas for online education consumer choice behavior research and ICT and content and provides a new scenario.This article is a cross-disciplinary research content in theory,and its innovation opens up a new path for the management of ICT research.The research results have innovative significance and value at both the theoretical and practical levels.展开更多
NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degra...NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degraded due to signal occlusion and even fails to achieve positioning due to the insufficient visible satellites.Because of the characteristics of large band-width,low latency,and high Base Station(BS)density,the fifth-Generation mobile communication(5G)technology has gradually become a trend for positioning in cities while offering traditional communication service.To supply the communication demands of the User Equipment(UE),only one BS is usually considered to establish a connection with the UE during the BS construction.However,the positioning accuracy with a single BS in urban canyons will be significantly reduced.To further improve the positioning accuracy in such extreme scenarios,this paper proposes a simplified 5G/GNSS fusion positioning system architecture using observations from only a 5G BS and a GNSS satellite.In this system,the GNSS receiver is mounted on the 5G BS,and the measurements provided by the receiver are used to form the differential code and complete the position estimation.The positioning mathematical models of the system based on the original code and differential code are derived.Then,the impacts of the measurements noise and the time synchronization error on the positioning accuracy are analyzed theoretically.Finally,the positioning performance is investigated by a set of simulation experiments.Numerical results show that under the existing 5G measurement noise and 2 m’s code measurement noise,the improvement of the differential code based fusion positioning compared with the 5G-only positioning is more than 32%,which is also about 6%higher than the original code based fusion positioning.Besides,this improvement is not affected by the time synchronization error between the BS and the GNSS satellite.展开更多
Abstract:Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications.However,there are still some locations where this is diffcult to achieve.This is the case on mo...Abstract:Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications.However,there are still some locations where this is diffcult to achieve.This is the case on moving vehicles and,particularly,on trains.Among the possible solutions to this problem,RoF(Radio-over-Fiber)architectures have been proposed as low-latency,cost-e ective candidates.Two elements are introduced to extend the RoF approach.First,the carrier frequency is raised into the W-band(75-110 GHz)to increase the available capacity.Second,a mechanical beam-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path,thereby enhancing the coverage area.The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless link is evaluated in terms of real-time BER(Bit Error Rate)measurements.The receiver is situated in di erent positions,and the orientation of the transmitter is changed accordingly.Values below the forward error correction limit for 7%overhead are obtained over a range of 60 cm around a center point situated 2 m away from the transmitter.展开更多
文摘A novel phased array antenna consisting of 256 elements is presented and experimentally verified for 5G millimeter-wave wireless communications.The antenna integrated with a wave control circuit can perform real-time beam scanning by reconfiguring the phase of an antenna unit.The unit,designed at 28 GHz using a simple patch structure with one PIN diode,can be electronically controlled to generate 1 bit phase quantization.A prototype of the antenna is fabricated and measured to demonstrate the feasibility of this approach.The measurement results indicate that the antenna achieves high gain and fast beam-steering,with the scan beams within±60°range and the maximum gain up to 21.7 dBi.Furthermore,it is also tested for wireless video transmission.In ZTE Shanghai,the antenna was used for the 5G New Radio(NR)test.The error vector magnitude(EVM)is less than 3%and the adjacent channel leakage ratio(ACLR)less than−35 dBc,which can meet 5G system requirements.Compared with the conventional phased array antenna,the proposed phased array has the advantages of low power consumption,low cost and conformal geometry.Due to these characteristics,the antenna is promising for wide applications in 5G millimeter-wave communication systems.
基金This work was supported by the Postdoctoral Fellowship Scheme under the Professional Development Research University from Universiti Teknologi Malaysia(UTM)under Grant 06E07.
文摘Compact fifth-generation(5G)low-frequency band filtering antennas(filtennas)with stable directive radiation patterns,improved bandwidth(BW),and gain are designed,fabricated,and tested in this research.The proposed filtennas are achieved by combining the predesigned compact 5G(5.975–7.125 GHz)third-order uniform and non-uniform transmission line hairpin bandpass filters(UTL and NTL HPBFs)with the compact ultrawide band Vivaldi tapered slot antenna(UWB VTSA)in one module.The objective of this integration is to enhance the performance of 5.975–7.125GHz filtennas which will be suitable for modern mobile communication applications by exploiting the benefits of UWB VTSA.Based on NTL HPBF,more space is provided to add the direct current(DC)biassing circuits in cognitive radio networks(CRNs)for frequency reconfigurable applications.To overcome the mismatch between HPBFs and VTSA,detailed parametric studies are presented.Computer simulation technology(CST)software is used for the simulation in this study.Good measured S11 appeared to be<−13 and<−10.54 dB at 5.48–7.73 and 5.9–7.98GHz with peak realized gains of 6.37 and 6.27 dBi,for VTSA with UTL and NTL HPBFs,respectively which outperforms the predesigned filters.Validation is carried out by comparing the measured and simulated results.
基金supported by National Social Science Fund Youth Project“Research on the Group Behavior of‘Post-95’College Students Based on Complex Networks”of China(Project Number:17CKS047)。
文摘The application of information and communications technology(ICT)in the education industry is becoming more and more extensive,and online education realized through ICT is developing in full swing.The influence of ICT on online education consumer's choice behavior is the core issue of online education industry development research.The research on the interactive path and methods of information and online education consumer choice behavior is worth exploring and revealing.This study introduces the word-of-mouth factor as a new research variable under the framework of the Rational Choice Theory model(RCT)and the structural equation method to conduct empirical research and theoretical analysis to verify the validity of the hypothesis and model.The fifthGeneration mobile communication system(5 G)analyses the factors affecting online education consumer behavior choices based on the premise of ICT.Research on the path between ICT and choice behavior provides new ideas for online education consumer choice behavior research and ICT and content and provides a new scenario.This article is a cross-disciplinary research content in theory,and its innovation opens up a new path for the management of ICT research.The research results have innovative significance and value at both the theoretical and practical levels.
基金supported by the National tural Science Foundation of ChinaNa[grant number 41974038]NaThe tional Key Research and Development Program of China[grant number 2018YFC0809804].
文摘NaGlobal vigation Satellite System(GNSS)positioning technology is widely used for its high precision,global,and all-weather service.However,in complex environments such as urban canyons,GNSS performance is often degraded due to signal occlusion and even fails to achieve positioning due to the insufficient visible satellites.Because of the characteristics of large band-width,low latency,and high Base Station(BS)density,the fifth-Generation mobile communication(5G)technology has gradually become a trend for positioning in cities while offering traditional communication service.To supply the communication demands of the User Equipment(UE),only one BS is usually considered to establish a connection with the UE during the BS construction.However,the positioning accuracy with a single BS in urban canyons will be significantly reduced.To further improve the positioning accuracy in such extreme scenarios,this paper proposes a simplified 5G/GNSS fusion positioning system architecture using observations from only a 5G BS and a GNSS satellite.In this system,the GNSS receiver is mounted on the 5G BS,and the measurements provided by the receiver are used to form the differential code and complete the position estimation.The positioning mathematical models of the system based on the original code and differential code are derived.Then,the impacts of the measurements noise and the time synchronization error on the positioning accuracy are analyzed theoretically.Finally,the positioning performance is investigated by a set of simulation experiments.Numerical results show that under the existing 5G measurement noise and 2 m’s code measurement noise,the improvement of the differential code based fusion positioning compared with the 5G-only positioning is more than 32%,which is also about 6%higher than the original code based fusion positioning.Besides,this improvement is not affected by the time synchronization error between the BS and the GNSS satellite.
基金This work is supported by the Marie Sk lodowska-Curie Innovative Training Network CELTA supported by the European Union's Horizon 2020 research and innovation programme(No.675683)the Innovative Training Network FiWiN5G project founded by the European Union's Horizon 2020 research and innovation programme(No.642355).
文摘Abstract:Ubiquitous broadband Internet access is one of the major goals of the next generation of wireless communications.However,there are still some locations where this is diffcult to achieve.This is the case on moving vehicles and,particularly,on trains.Among the possible solutions to this problem,RoF(Radio-over-Fiber)architectures have been proposed as low-latency,cost-e ective candidates.Two elements are introduced to extend the RoF approach.First,the carrier frequency is raised into the W-band(75-110 GHz)to increase the available capacity.Second,a mechanical beam-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path,thereby enhancing the coverage area.The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless link is evaluated in terms of real-time BER(Bit Error Rate)measurements.The receiver is situated in di erent positions,and the orientation of the transmitter is changed accordingly.Values below the forward error correction limit for 7%overhead are obtained over a range of 60 cm around a center point situated 2 m away from the transmitter.