In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging ...In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging due to the unaffordable cost and high complexity when testing a large number of antennas. To solve this problem, the over-the-air (OTA) test has been presented, in which probe selection is the key to reduce the number of channel emulators and probes. In this paper, a novel artificial bee colony (ABC) algorithm is introduced to enhance the efficiency and accuracy of probe selection procedure. A sectoring- based multi-probe anechoic chamber (MPAC) is built to evaluate the throughput performance of massive MIMO equipped in 5G BS. In addition, link level simulation is carried out to evaluate the proposal’s performance gain under the commercial network assumptions, where the average throughput of three velocity is given with different SNR region. The results suggest that OTA chamber and multi-probe wall are available not only for 5G BSs, but also for user equipments (UEs) with end-to-end communication.展开更多
According to the Technical Guide for Climatic Feasibility Demonstration of Airport Project Site Selection,via statistical analysis on historical climate data of reference weather station,climatic background characteri...According to the Technical Guide for Climatic Feasibility Demonstration of Airport Project Site Selection,via statistical analysis on historical climate data of reference weather station,climatic background characteristics and meteorological disaster situation of preselected site,and characteristics of seasonal distribution,interannual variation and long-term trend of main meteorological elements and disasters were summarized.The difference of meteorological elements between preselected site and reference weather station and its cause were analyzed,and fine analysis of fog,low visibility event,wind,cloud and other meteorological elements or weather with high influence in preselected site was conducted.Climatic feasibility,advantages and disadvantages of meteorological conditions and possible meteorological risks in preselected site were evaluated.The research could provide decision-making basis for site selection of Lingling Airport and airport engineering design.Moreover,key technology route and research results were extracted,and technical analysis process of demonstration report was integrated,which could provide reference for climate feasibility demonstration on site selection of similar airports in China.展开更多
This paper presents an optimization model for the location and capacity of electric vehicle(EV)charging stations.The model takes the multiple factors of the“vehicle-station-grid”system into account.Then,ArcScene is ...This paper presents an optimization model for the location and capacity of electric vehicle(EV)charging stations.The model takes the multiple factors of the“vehicle-station-grid”system into account.Then,ArcScene is used to couple the road and power grid models and ensure that the coupling system is strictly under the goal of minimizing the total social cost,which includes the operator cost,user charging cost,and power grid loss.An immune particle swarm optimization algorithm(IPSOA)is proposed in this paper to obtain the optimal coupling strategy.The simulation results show that the algorithm has good convergence and performs well in solving multi-modal problems.It also balances the interests of users,operators,and the power grid.Compared with other schemes,the grid loss cost is reduced by 11.1%and 17.8%,and the total social cost decreases by 9.96%and 3.22%.展开更多
基金supported by the State Major Science and Technology Special Projects under Grant No. 2018ZX03001028-003
文摘In 5G systems, massive multiple-input multiple-output (MIMO) has been adopted in base stations (BSs) to improve spectral efficiency and coverage. The traditional conductive performance test techniques are challenging due to the unaffordable cost and high complexity when testing a large number of antennas. To solve this problem, the over-the-air (OTA) test has been presented, in which probe selection is the key to reduce the number of channel emulators and probes. In this paper, a novel artificial bee colony (ABC) algorithm is introduced to enhance the efficiency and accuracy of probe selection procedure. A sectoring- based multi-probe anechoic chamber (MPAC) is built to evaluate the throughput performance of massive MIMO equipped in 5G BS. In addition, link level simulation is carried out to evaluate the proposal’s performance gain under the commercial network assumptions, where the average throughput of three velocity is given with different SNR region. The results suggest that OTA chamber and multi-probe wall are available not only for 5G BSs, but also for user equipments (UEs) with end-to-end communication.
文摘According to the Technical Guide for Climatic Feasibility Demonstration of Airport Project Site Selection,via statistical analysis on historical climate data of reference weather station,climatic background characteristics and meteorological disaster situation of preselected site,and characteristics of seasonal distribution,interannual variation and long-term trend of main meteorological elements and disasters were summarized.The difference of meteorological elements between preselected site and reference weather station and its cause were analyzed,and fine analysis of fog,low visibility event,wind,cloud and other meteorological elements or weather with high influence in preselected site was conducted.Climatic feasibility,advantages and disadvantages of meteorological conditions and possible meteorological risks in preselected site were evaluated.The research could provide decision-making basis for site selection of Lingling Airport and airport engineering design.Moreover,key technology route and research results were extracted,and technical analysis process of demonstration report was integrated,which could provide reference for climate feasibility demonstration on site selection of similar airports in China.
基金supported by the Major Science and Technology Projects in Gansu Province(2023ZDGA005).
文摘This paper presents an optimization model for the location and capacity of electric vehicle(EV)charging stations.The model takes the multiple factors of the“vehicle-station-grid”system into account.Then,ArcScene is used to couple the road and power grid models and ensure that the coupling system is strictly under the goal of minimizing the total social cost,which includes the operator cost,user charging cost,and power grid loss.An immune particle swarm optimization algorithm(IPSOA)is proposed in this paper to obtain the optimal coupling strategy.The simulation results show that the algorithm has good convergence and performs well in solving multi-modal problems.It also balances the interests of users,operators,and the power grid.Compared with other schemes,the grid loss cost is reduced by 11.1%and 17.8%,and the total social cost decreases by 9.96%and 3.22%.
