[Objective]This paper aims to study the heredity and parental correlation of the oil content of the beginning of the generation at highoil content soybean.[Methods]Seven high yield or high-oil content soybean are sele...[Objective]This paper aims to study the heredity and parental correlation of the oil content of the beginning of the generation at highoil content soybean.[Methods]Seven high yield or high-oil content soybean are selected and eight crosses are made according to the NCII design.[Results]The variation of oil content in F5 relates with the difference between parents.The more the differences between both parents have,the more variations of the oil content of F5 become.When the oil content of both parents are high,and the maturating time of them are very different,the probability of high-oil plant in F5 derived from these cross are high.The oil content of F5 generation has negative correlation with the different between both parents and has positive correlation with the oil content of male parent and significant positive correlation with the oil content of female parent and mid-parent.[Conclusions]This study result provide reference for the seedling of High-oil Content Soybean.展开更多
The paper aimed to illustrate an idea about the feasibility of a peculiar aircraft, i.e., a 5th generation light fighter. At first, a short description of previous "generations" of jet fighter is given, introducing ...The paper aimed to illustrate an idea about the feasibility of a peculiar aircraft, i.e., a 5th generation light fighter. At first, a short description of previous "generations" of jet fighter is given, introducing the interest that has always been originated by the concept of"light fighter" for every of the first four fighter generations. The derivation of the first idea of a new 5th generation light fighter is then described. Then to further investigate the feasibility of idea, a conceptual design study has been driven up by utilizing peculiar tools, both for quantitative and qualitative (i.e., the aircraft layout definition) evaluations. With the further support of preliminary study of subsystems, the result shows the feasibility of the concept.展开更多
A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed formillimeter-wave communication systems in this paper.Themultiple-input-multiple-output(MIMO)antenna geom...A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed formillimeter-wave communication systems in this paper.Themultiple-input-multiple-output(MIMO)antenna geometry consists of a slotted ellipse enclosed within a hollow circle which is orthogonally rotated with a connected partial ground at the back.The overall size of the four elements MIMO antenna is 2.24λ×2.24λ(at 27.12GHz).The prototype of four-element MIMOresonator is designed and printed using Rogers RTDuroid 5880 withε_(r)=2.2 and loss tangent=0.0009 and having a thickness of 0.8 mm.It covers dual-band having a fractional bandwidth of 15.7%(27.12-31.34 GHz)and 4.2%(37.21-38.81 GHz)for millimeter-wave applications with a gain of more than 4 dBi at both bands.The proposed antenna analysis in terms ofMIMOdiversity parameters(Envelope Correlation Coefficient(ECC)and Diversity Gain(DG))is also carried out.The experimental result in terms of reflection coefficient,radiation pattern,gain and MIMOdiversity parameter correlates very well with the simulated ones that show the potential of the proposed design for MIMO applications at millimeter-wave frequencies.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
With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G)...With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications.展开更多
Demand for water is expanding with increases in population,particularly in urban areas in developing countries.Additionally,urban water system needs a novel perspective for upgradation with urbanization.This perspecti...Demand for water is expanding with increases in population,particularly in urban areas in developing countries.Additionally,urban water system needs a novel perspective for upgradation with urbanization.This perspective presents a novel 5R approach for managing urban water resources:Recover(storm water),Reduce(toilet flushing water),Recycle(gray water),Resource(black water),and Reuse(advanced-treated wastewater).The 5R generation incorporates the latest ideas for harvesting storm water,gray water,and black water in its several forms.This paper has briefly demonstrated each R of 5R generation for water treatment and reuse.China has the chance to upgrade its urban water systems according to 5R principles.Already,a demonstration project of 5R generation has been installed in Qingdao International Horticultural Exposition,and Dalian International Convention Center(China)has applied 5R,achieving over 70%water saving.The 5R offers promise for moving solutions for urban water scarcity from“hoped for in the future”to“realistic today”.展开更多
The directional neighbor discovery problem,i.e,spatial rendezvous,is a fundamental problem in millimeter wave(mmWave)wireless networks,where directional transmissions are used to overcome the high attenuation.The chal...The directional neighbor discovery problem,i.e,spatial rendezvous,is a fundamental problem in millimeter wave(mmWave)wireless networks,where directional transmissions are used to overcome the high attenuation.The challenge is how to let the transmitter and the receiver beams meet in space under deafness caused by directional transmission and reception,where no control channel,prior information,and coordination are available.In this paper,we present a Hunting based Directional Neighbor Discovery(HDND)scheme for ad hoc mmWave networks,where a node follows a unique sequence to determine its transmission or reception mode,and continuously r0-tates its directional beam to scan the neighborhood for other mmWave nodes.Through a rigorous analysis,we derive the conditions for ensured neighbor discovery,as well as a bound for the worst-case discovery time and the impact of sidelobes.We validate the analysis with extensive simulations and demonstrate the superior perfor-mance of the proposed scheme over several baseline schemes.展开更多
With the support by the Thousand Talents Program and the National Natural Science Foundation of China,the research team led by Prof.Xiu Faxian(修发贤)at the State Key Laboratory of Surface Physics,Department of Phys...With the support by the Thousand Talents Program and the National Natural Science Foundation of China,the research team led by Prof.Xiu Faxian(修发贤)at the State Key Laboratory of Surface Physics,Department of Physics,Fudan University,uncovered the dynamical mass generation in the Dirac semimetal ZrTe5,which was published in Nature Communications(2016,DOI:10.1038/NCOMMS12516).展开更多
The Internet of Things(IoT)is playing an important role in providing access to affordable,clean and green energy worldwide through the use of smart devices.The current electric power networks will be more reliable,sec...The Internet of Things(IoT)is playing an important role in providing access to affordable,clean and green energy worldwide through the use of smart devices.The current electric power networks will be more reliable,secure,flexible and durable by implementing IoT in power systems.This paper presents a brief discussion about IoT contributions in the development of power systems from a generation,transmission,distribution and consumption point of view.5G cellular networks have a great potential for the development of IoT technology.Additionally,5G cellular networks can be instrumental in supporting the greater communication needs of IoT.This review provides a comprehensive analysis about the role of 5G cellular networks in the growth of IoT technology and power systems.Large amounts of data will be generated due to the incorporation of renewable energy,deployment of the smart grid and the improvements to the electricity market.In this way,in order to realize the connection between things and people,things and things and people and people in power systems,it is essential to apply IoT in power systems.In this case,5G is providing numerous advantages to Power IoT(PIoT)by offering greater opportunities in progress and improvements;however,there are also numerous challenges with the deployment of 5G in PIoT.Finally,this review article provides an overview of the role,implications and challenges of 5G in PIoT.展开更多
We introduce the basic concept,background,and development of mobile communication systems from the first generation(1G)to the fifth generation(5G)including their antenna systems.We also describe the requirements for 5...We introduce the basic concept,background,and development of mobile communication systems from the first generation(1G)to the fifth generation(5G)including their antenna systems.We also describe the requirements for 5G networking and optimization of antenna systems,and present the basic principle of three-dimensional array antennas.Weight optimization methods of massive multiple-input multiple-output(MIMO)antennas are proposed and verified.Finally,several ideas are given to solve the problem of power consumption of 5G antenna systems.展开更多
A dual-polarized multiple-input multiple-output(MIMO)antenna is proposed for 5G base stations.Each antenna element consists of two orthogonally placed fan-shaped dipole elements and45°dual-polarized feed-ing str...A dual-polarized multiple-input multiple-output(MIMO)antenna is proposed for 5G base stations.Each antenna element consists of two orthogonally placed fan-shaped dipole elements and45°dual-polarized feed-ing structures are used to achieve broadband operation.The resonant frequency of the array element is from 3.3 to 4.2 GHz,which covers the mainstream spectrum allocations of 5G mobile networks.H-shaped coupling elements are used to improve the isolation between the neighboring antenna elements and the mutual coupling is reduced by over 4 dB.The envelope correlation of a 2×2 array is provided for verification.展开更多
The fifth generation(5G)of wireless networks features three core use cases,namely ultra-reliable and low latency communications(URLLC),massive machine type communications(mMTC),and enhanced mobile broadband(eMBB).Thes...The fifth generation(5G)of wireless networks features three core use cases,namely ultra-reliable and low latency communications(URLLC),massive machine type communications(mMTC),and enhanced mobile broadband(eMBB).These use cases co-exist in many practical scenarios and compete for the same set of time and frequency resources,resulting in a natural trade-off in their performance.In this paper,a network supporting both URLLC and eMBB modes of operation is studied.To guarantee the ultra low latency requirement of URLLC,a dynamic resource allocation scheme indicated by a two-dimensional bitmap is proposed.This approach is capable to achieve finer granularity as well as lower false cancellation rate compared to the state-of-the-art methods.A novel power control and indication method is also proposed to dynamically provide different power control parameters to the user equipment(UE),while guaranteeing the reliability requirement of URLLC and minimizing the impact to eMBB.In addition,we devise a dynamic selection mechanism(DSM)to accommodate diverse scenarios,which is empowered with load prediction to become more intelligent.Our extensive system-level simulation results for eMBB-URLLC co-existence scenarios showcase that the perceived throughput of eMBB UEs is increased by 45.3%,while about 13.3% more UEs are enjoying URLLC services with at most 84% transmit power savings compared to the state-of-the-art methods.展开更多
The application of the artificial intelligence(AI) technology in the 5 th generation mobile communication system(5 G) networks promotes the development of the mobile communication network and its application in vertic...The application of the artificial intelligence(AI) technology in the 5 th generation mobile communication system(5 G) networks promotes the development of the mobile communication network and its application in vertical industries, however, the application models of "patching" and "plug-in" have hindered the effect of AI applications. Meanwhile, the application of AI in all walks of life puts forward requirements for new capabilities of the future network, such as distributed training, real-time collaborative inference, local data processing, etc., which require "native intelligence design" in future networks. This paper discusses the requirements of native intelligence in the 6 th generation mobile communication system(6 G) networks from the perspectives of 5 G intelligent network challenges and the "ubiquitous intelligence" vision of 6 G, and analyzes the technical challenges of the AI workflows in its lifecycle and the AI as a service(AIaaS) in cloud network. The progress and deficiencies of the current research on AI functional architecture in various industry organizations are summarized. The end-to-end functional architecture for native AI for 6 G network and its three key technical characteristics are proposed: quality of AI services(QoAIS) based AI service orchestration for its full lifecycle, deep integration of native AI computing and communication, and integration of native AI and digital twin network. The directions of future research are also prospected.展开更多
Over-the-air(OTA)testing is an industry standard practice for evaluating transceiver performance in wireless devices.For the fifth generation(5G)and beyond wireless systems with high integration,OTA testing is probabl...Over-the-air(OTA)testing is an industry standard practice for evaluating transceiver performance in wireless devices.For the fifth generation(5G)and beyond wireless systems with high integration,OTA testing is probably the only reliable method to accurately measure the transceiver performance,suitable for certification as well as for providing feedback for design verification and optimization.Further,multiple-input multiple-output(MIMO)technology is extensively applied for stable connection,high throughput rate,and low latency.In this paper,we provide an overview of the three main methods for evaluating the MIMO OTA performance,namely,the multiprobe anechoic chamber(MPAC)method,the reverberation chamber plus channel emulator(RC+CE)method,and the radiated two-stage(RTS)method,with the aim of providing a useful guideline for developing effective wireless performance testing in future 5G-and-beyond wireless systems.展开更多
We study the performance of space division multiple access (SDMA) under a non-ideal engineering situation. When the SDMA channel is of high inter-layer correlation and the condition number is large, the multiple use...We study the performance of space division multiple access (SDMA) under a non-ideal engineering situation. When the SDMA channel is of high inter-layer correlation and the condition number is large, the multiple user multiple input and multiple output user equipment (MUMIMOUE) grouping should be optimized, and in some cases further dimension-reduction should be applied. As the channel measuring is always non-ideal, we use two methods, feedback mode and non-feedback mode, in terms of performance and overhead. It is proposed that the non-feedback mode is preferable even for some non-reciprocal channels. Prin- ciple analysis and test results are given.展开更多
It has been an exciting journey since the mobile communications and artificial intelligence(AI)were conceived in 1983 and 1956.While both fields evolved independently and profoundly changed communications and computin...It has been an exciting journey since the mobile communications and artificial intelligence(AI)were conceived in 1983 and 1956.While both fields evolved independently and profoundly changed communications and computing industries,the rapid convergence of 5th generation mobile communication technology(5G)and AI is beginning to significantly transform the core communication infrastructure,network management,and vertical applications.The paper first outlined the individual roadmaps of mobile communications and AI in the early stage,with a concentration to review the era from 3rd generation mobile communication technology(3G)to 5G when AI and mobile communications started to converge.With regard to telecommunications AI,the progress of AI in the ecosystem of mobile communications was further introduced in detail,including network infrastructure,network operation and management,business operation and management,intelligent applications towards business supporting system(BSS)&operation supporting system(OSS)convergence,verticals and private networks,etc.Then the classifications of AI in telecommunication ecosystems were summarized along with its evolution paths specified by various international telecommunications standardization organizations.Towards the next decade,the prospective roadmap of telecommunications AI was forecasted.In line with 3rd generation partnership project(3GPP)and International Telecommunication Union Radiocommunication Sector(ITU-R)timeline of 5G&6th generation mobile communication technology(6G),the network intelligence following 3GPP and open radio access network(O-RAN)routes,experience and intent-based network management and operation,network AI signaling system,intelligent middle-office based BSS,intelligent customer experience management and policy control driven by BSS&OSS convergence,evolution from service level agreement(SLA)to experience level agreement(ELA),and intelligent private network for verticals were further explored.The paper is concluded with the vision that AI will reshape the future beyond 5G(B5G)/6G landscape,and we need pivot our research and development(R&D),standardizations,and ecosystem to fully take the unprecedented opportunities.展开更多
文摘[Objective]This paper aims to study the heredity and parental correlation of the oil content of the beginning of the generation at highoil content soybean.[Methods]Seven high yield or high-oil content soybean are selected and eight crosses are made according to the NCII design.[Results]The variation of oil content in F5 relates with the difference between parents.The more the differences between both parents have,the more variations of the oil content of F5 become.When the oil content of both parents are high,and the maturating time of them are very different,the probability of high-oil plant in F5 derived from these cross are high.The oil content of F5 generation has negative correlation with the different between both parents and has positive correlation with the oil content of male parent and significant positive correlation with the oil content of female parent and mid-parent.[Conclusions]This study result provide reference for the seedling of High-oil Content Soybean.
文摘The paper aimed to illustrate an idea about the feasibility of a peculiar aircraft, i.e., a 5th generation light fighter. At first, a short description of previous "generations" of jet fighter is given, introducing the interest that has always been originated by the concept of"light fighter" for every of the first four fighter generations. The derivation of the first idea of a new 5th generation light fighter is then described. Then to further investigate the feasibility of idea, a conceptual design study has been driven up by utilizing peculiar tools, both for quantitative and qualitative (i.e., the aircraft layout definition) evaluations. With the further support of preliminary study of subsystems, the result shows the feasibility of the concept.
基金This work is supported by the Moore4Medical Project,funded within ECSEL JU in collaboration with the EU H2020 Framework Programme(H2020/2014-2020)under Grant Agreement H2020-ECSEL-2019-IA-876190Fundacao para a Ciência eTecnologia(ECSEL/0006/2019)This work is also funded by the FCT/MEC through national funds and when applicable co-financed by the ERDF,under the PT2020 Partnership Agreement under the UID/EEA/50008/2020 Project.
文摘A four-element compact dual-band patch antenna having a common ground plane operating at 28/38 GHz is proposed formillimeter-wave communication systems in this paper.Themultiple-input-multiple-output(MIMO)antenna geometry consists of a slotted ellipse enclosed within a hollow circle which is orthogonally rotated with a connected partial ground at the back.The overall size of the four elements MIMO antenna is 2.24λ×2.24λ(at 27.12GHz).The prototype of four-element MIMOresonator is designed and printed using Rogers RTDuroid 5880 withε_(r)=2.2 and loss tangent=0.0009 and having a thickness of 0.8 mm.It covers dual-band having a fractional bandwidth of 15.7%(27.12-31.34 GHz)and 4.2%(37.21-38.81 GHz)for millimeter-wave applications with a gain of more than 4 dBi at both bands.The proposed antenna analysis in terms ofMIMOdiversity parameters(Envelope Correlation Coefficient(ECC)and Diversity Gain(DG))is also carried out.The experimental result in terms of reflection coefficient,radiation pattern,gain and MIMOdiversity parameter correlates very well with the simulated ones that show the potential of the proposed design for MIMO applications at millimeter-wave frequencies.
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 the National High Technology Research and Development Program of China (863 program) of China under Grant No.2011AA010200 supported by the National Natural Science Foundation of China (NSFC) under Grant No.61771116 and No.91738102
文摘With the exponential growth of the data traffic in wireless communication systems, terahertz(THz) frequency band is envisioned as a promising candidate to support ultra-broadband for future beyond fifth generation(5G), bridging the gap between millimeter wave(mmWave) and optical frequency ranges. The purpose of this paper is to provide a comprehensive literature review on the development towards THz communications and presents some key technologies faced in THz wireless communication systems. Firstly, despite the substantial hardware problems that have to be developed in terms of the THz solid state superheterodyne receiver, high speed THz modulators and THz antennas, the practical THz channel model and the efficient THz beamforming are also described to compensate for the severe path attenuation. Moreover, two different kinds of lab-level THz communication systems are introduced minutely, named a solid state THz communication system and a spatial direct modulation THz communication system, respectively. The solid state THz system converts intermediate frequency(IF) modulated signal to THz frequency while the direct modulation THz system allows the high power THz sources to input for approving the relatively long distance communications. Finally, we discuss several potential application scenarios as well as some vital technical challenges that will be encountered in the future THz communications.
基金This study was funded by the National Key Research and Development Program of China(No.2017YFC0403400).
文摘Demand for water is expanding with increases in population,particularly in urban areas in developing countries.Additionally,urban water system needs a novel perspective for upgradation with urbanization.This perspective presents a novel 5R approach for managing urban water resources:Recover(storm water),Reduce(toilet flushing water),Recycle(gray water),Resource(black water),and Reuse(advanced-treated wastewater).The 5R generation incorporates the latest ideas for harvesting storm water,gray water,and black water in its several forms.This paper has briefly demonstrated each R of 5R generation for water treatment and reuse.China has the chance to upgrade its urban water systems according to 5R principles.Already,a demonstration project of 5R generation has been installed in Qingdao International Horticultural Exposition,and Dalian International Convention Center(China)has applied 5R,achieving over 70%water saving.The 5R offers promise for moving solutions for urban water scarcity from“hoped for in the future”to“realistic today”.
基金This work was supported in part by the NSF under Grants ECCS-1923717 and CNS-1320472the Wireless Engineering Research and Education Center,Auburn University,Auburn,AL,USA.
文摘The directional neighbor discovery problem,i.e,spatial rendezvous,is a fundamental problem in millimeter wave(mmWave)wireless networks,where directional transmissions are used to overcome the high attenuation.The challenge is how to let the transmitter and the receiver beams meet in space under deafness caused by directional transmission and reception,where no control channel,prior information,and coordination are available.In this paper,we present a Hunting based Directional Neighbor Discovery(HDND)scheme for ad hoc mmWave networks,where a node follows a unique sequence to determine its transmission or reception mode,and continuously r0-tates its directional beam to scan the neighborhood for other mmWave nodes.Through a rigorous analysis,we derive the conditions for ensured neighbor discovery,as well as a bound for the worst-case discovery time and the impact of sidelobes.We validate the analysis with extensive simulations and demonstrate the superior perfor-mance of the proposed scheme over several baseline schemes.
文摘With the support by the Thousand Talents Program and the National Natural Science Foundation of China,the research team led by Prof.Xiu Faxian(修发贤)at the State Key Laboratory of Surface Physics,Department of Physics,Fudan University,uncovered the dynamical mass generation in the Dirac semimetal ZrTe5,which was published in Nature Communications(2016,DOI:10.1038/NCOMMS12516).
文摘The Internet of Things(IoT)is playing an important role in providing access to affordable,clean and green energy worldwide through the use of smart devices.The current electric power networks will be more reliable,secure,flexible and durable by implementing IoT in power systems.This paper presents a brief discussion about IoT contributions in the development of power systems from a generation,transmission,distribution and consumption point of view.5G cellular networks have a great potential for the development of IoT technology.Additionally,5G cellular networks can be instrumental in supporting the greater communication needs of IoT.This review provides a comprehensive analysis about the role of 5G cellular networks in the growth of IoT technology and power systems.Large amounts of data will be generated due to the incorporation of renewable energy,deployment of the smart grid and the improvements to the electricity market.In this way,in order to realize the connection between things and people,things and things and people and people in power systems,it is essential to apply IoT in power systems.In this case,5G is providing numerous advantages to Power IoT(PIoT)by offering greater opportunities in progress and improvements;however,there are also numerous challenges with the deployment of 5G in PIoT.Finally,this review article provides an overview of the role,implications and challenges of 5G in PIoT.
基金supported by the National Major Projects of China(No.2018ZX03001022-001)。
文摘We introduce the basic concept,background,and development of mobile communication systems from the first generation(1G)to the fifth generation(5G)including their antenna systems.We also describe the requirements for 5G networking and optimization of antenna systems,and present the basic principle of three-dimensional array antennas.Weight optimization methods of massive multiple-input multiple-output(MIMO)antennas are proposed and verified.Finally,several ideas are given to solve the problem of power consumption of 5G antenna systems.
文摘A dual-polarized multiple-input multiple-output(MIMO)antenna is proposed for 5G base stations.Each antenna element consists of two orthogonally placed fan-shaped dipole elements and45°dual-polarized feed-ing structures are used to achieve broadband operation.The resonant frequency of the array element is from 3.3 to 4.2 GHz,which covers the mainstream spectrum allocations of 5G mobile networks.H-shaped coupling elements are used to improve the isolation between the neighboring antenna elements and the mutual coupling is reduced by over 4 dB.The envelope correlation of a 2×2 array is provided for verification.
文摘The fifth generation(5G)of wireless networks features three core use cases,namely ultra-reliable and low latency communications(URLLC),massive machine type communications(mMTC),and enhanced mobile broadband(eMBB).These use cases co-exist in many practical scenarios and compete for the same set of time and frequency resources,resulting in a natural trade-off in their performance.In this paper,a network supporting both URLLC and eMBB modes of operation is studied.To guarantee the ultra low latency requirement of URLLC,a dynamic resource allocation scheme indicated by a two-dimensional bitmap is proposed.This approach is capable to achieve finer granularity as well as lower false cancellation rate compared to the state-of-the-art methods.A novel power control and indication method is also proposed to dynamically provide different power control parameters to the user equipment(UE),while guaranteeing the reliability requirement of URLLC and minimizing the impact to eMBB.In addition,we devise a dynamic selection mechanism(DSM)to accommodate diverse scenarios,which is empowered with load prediction to become more intelligent.Our extensive system-level simulation results for eMBB-URLLC co-existence scenarios showcase that the perceived throughput of eMBB UEs is increased by 45.3%,while about 13.3% more UEs are enjoying URLLC services with at most 84% transmit power savings compared to the state-of-the-art methods.
基金supported by the National Key R&D Program of China (2020YFB1806800)。
文摘The application of the artificial intelligence(AI) technology in the 5 th generation mobile communication system(5 G) networks promotes the development of the mobile communication network and its application in vertical industries, however, the application models of "patching" and "plug-in" have hindered the effect of AI applications. Meanwhile, the application of AI in all walks of life puts forward requirements for new capabilities of the future network, such as distributed training, real-time collaborative inference, local data processing, etc., which require "native intelligence design" in future networks. This paper discusses the requirements of native intelligence in the 6 th generation mobile communication system(6 G) networks from the perspectives of 5 G intelligent network challenges and the "ubiquitous intelligence" vision of 6 G, and analyzes the technical challenges of the AI workflows in its lifecycle and the AI as a service(AIaaS) in cloud network. The progress and deficiencies of the current research on AI functional architecture in various industry organizations are summarized. The end-to-end functional architecture for native AI for 6 G network and its three key technical characteristics are proposed: quality of AI services(QoAIS) based AI service orchestration for its full lifecycle, deep integration of native AI computing and communication, and integration of native AI and digital twin network. The directions of future research are also prospected.
基金Project supported by the National Natural Science Foundation of China(No.61671203)。
文摘Over-the-air(OTA)testing is an industry standard practice for evaluating transceiver performance in wireless devices.For the fifth generation(5G)and beyond wireless systems with high integration,OTA testing is probably the only reliable method to accurately measure the transceiver performance,suitable for certification as well as for providing feedback for design verification and optimization.Further,multiple-input multiple-output(MIMO)technology is extensively applied for stable connection,high throughput rate,and low latency.In this paper,we provide an overview of the three main methods for evaluating the MIMO OTA performance,namely,the multiprobe anechoic chamber(MPAC)method,the reverberation chamber plus channel emulator(RC+CE)method,and the radiated two-stage(RTS)method,with the aim of providing a useful guideline for developing effective wireless performance testing in future 5G-and-beyond wireless systems.
文摘We study the performance of space division multiple access (SDMA) under a non-ideal engineering situation. When the SDMA channel is of high inter-layer correlation and the condition number is large, the multiple user multiple input and multiple output user equipment (MUMIMOUE) grouping should be optimized, and in some cases further dimension-reduction should be applied. As the channel measuring is always non-ideal, we use two methods, feedback mode and non-feedback mode, in terms of performance and overhead. It is proposed that the non-feedback mode is preferable even for some non-reciprocal channels. Prin- ciple analysis and test results are given.
文摘It has been an exciting journey since the mobile communications and artificial intelligence(AI)were conceived in 1983 and 1956.While both fields evolved independently and profoundly changed communications and computing industries,the rapid convergence of 5th generation mobile communication technology(5G)and AI is beginning to significantly transform the core communication infrastructure,network management,and vertical applications.The paper first outlined the individual roadmaps of mobile communications and AI in the early stage,with a concentration to review the era from 3rd generation mobile communication technology(3G)to 5G when AI and mobile communications started to converge.With regard to telecommunications AI,the progress of AI in the ecosystem of mobile communications was further introduced in detail,including network infrastructure,network operation and management,business operation and management,intelligent applications towards business supporting system(BSS)&operation supporting system(OSS)convergence,verticals and private networks,etc.Then the classifications of AI in telecommunication ecosystems were summarized along with its evolution paths specified by various international telecommunications standardization organizations.Towards the next decade,the prospective roadmap of telecommunications AI was forecasted.In line with 3rd generation partnership project(3GPP)and International Telecommunication Union Radiocommunication Sector(ITU-R)timeline of 5G&6th generation mobile communication technology(6G),the network intelligence following 3GPP and open radio access network(O-RAN)routes,experience and intent-based network management and operation,network AI signaling system,intelligent middle-office based BSS,intelligent customer experience management and policy control driven by BSS&OSS convergence,evolution from service level agreement(SLA)to experience level agreement(ELA),and intelligent private network for verticals were further explored.The paper is concluded with the vision that AI will reshape the future beyond 5G(B5G)/6G landscape,and we need pivot our research and development(R&D),standardizations,and ecosystem to fully take the unprecedented opportunities.