The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is ...The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is a basic necessity and is normally categorized into control and nonpayload communication(CNPC) as well as payload communication. In this paper, we attempt to tackle two challenges of UAV communication respectively on establishing reliable CNPC links against the high mobility of UAVs as well as changeable communication conditions, and on offering dynamic resource optimization for Quality-of-Service(QoS) guaranteed payload communication with variable link connectivity. Firstly, we propose the concept of air controlling center(ACC), a virtual application equipped on the infrastructure in SAGINs, which can collect global information for estimating UAV trajectory and communication channels. We then introduce the knapsack problem for modelling resource optimization of UAV communication in order to provide optimal access points for both CNPC and payload communication. Meanwhile, using the air controlling information, predictive decision algorithm and handover strategy are introduced for the reliable connection with multiple access points. Simulation results demonstrate that our proposal ensures an approximate always-on reliable accessing of communication links and outperforms the existing methods against high mobility,sparse distribution, and physical obstacles.展开更多
针对低信噪比场景下多飞行目标波达方向(Direction of Arrival,DOA)估计精度不高,导致基于智能天线的民航地空通信抗干扰性能较差的问题,提出了一种基于航向训练模式和动态径向基神经网络(Radial Basis Function Neural Network,RBFNN)...针对低信噪比场景下多飞行目标波达方向(Direction of Arrival,DOA)估计精度不高,导致基于智能天线的民航地空通信抗干扰性能较差的问题,提出了一种基于航向训练模式和动态径向基神经网络(Radial Basis Function Neural Network,RBFNN)的多飞行目标追踪方法。首先融合二次雷达信息,建立民航飞行目标DOA变换关系;然后通过航向训练模式,粗估下一时刻各飞行目标DOA,并作为RBFNN的输入;最后构建隐含层中心动态调整的RBFNN,快速准确追踪各飞行目标DOA。实验表明,该方法可以大幅提高空中同时存在的多飞行目标DOA估计精度;结合波束形成技术,可以大幅提高民航地空通信系统的抗干扰能力,提升民航飞行安全水平;在5 dB信噪比条件下,相对基于常规智能天线的民航地空通信系统,抗干扰能力可以提升16 dB。展开更多
According to the analysis of the very high frequency (VHF) self organized time division multiple access (S TDMA) aviation data link, a new dynamic slot assignment scheme is proposed in this paper, which adopts var...According to the analysis of the very high frequency (VHF) self organized time division multiple access (S TDMA) aviation data link, a new dynamic slot assignment scheme is proposed in this paper, which adopts variable data frame structure and can eliminate the effect of the idle slot on message delay. By using queue theory, the analysis models of the new scheme and previous scheme are presented, and the performance of message delay and that of system throughput are analyzed under two schemes. The simulation results show that the new scheme has a better performance than the previous one in the message delay and system throughput.展开更多
In this paper, we discuss several large-scale fading models for different enviromnents. The COST231-Hata model is adapted for air-to-ground modeling. We propose two criteria for air-to- ground channel modelling based ...In this paper, we discuss several large-scale fading models for different enviromnents. The COST231-Hata model is adapted for air-to-ground modeling. We propose two criteria for air-to- ground channel modelling based on test data derived from field testing in Beijing. We develop a new propagation model that is more suitable for air-to-ground communication that previous models. We focus on improving this propagation model using the field test data.展开更多
基金supported by the the National Key Research and Development Program of China under No. 2019YFB1803200National Natural Science Foundation of China under Grants 61620106001。
文摘The cooperation of multiple Unmanned Aerial Vehicles(UAVs) has become a promising scenario in Space-Air-Ground Integrated Networks(SAGINs) recently due to their widespread applications,where wireless communication is a basic necessity and is normally categorized into control and nonpayload communication(CNPC) as well as payload communication. In this paper, we attempt to tackle two challenges of UAV communication respectively on establishing reliable CNPC links against the high mobility of UAVs as well as changeable communication conditions, and on offering dynamic resource optimization for Quality-of-Service(QoS) guaranteed payload communication with variable link connectivity. Firstly, we propose the concept of air controlling center(ACC), a virtual application equipped on the infrastructure in SAGINs, which can collect global information for estimating UAV trajectory and communication channels. We then introduce the knapsack problem for modelling resource optimization of UAV communication in order to provide optimal access points for both CNPC and payload communication. Meanwhile, using the air controlling information, predictive decision algorithm and handover strategy are introduced for the reliable connection with multiple access points. Simulation results demonstrate that our proposal ensures an approximate always-on reliable accessing of communication links and outperforms the existing methods against high mobility,sparse distribution, and physical obstacles.
文摘针对低信噪比场景下多飞行目标波达方向(Direction of Arrival,DOA)估计精度不高,导致基于智能天线的民航地空通信抗干扰性能较差的问题,提出了一种基于航向训练模式和动态径向基神经网络(Radial Basis Function Neural Network,RBFNN)的多飞行目标追踪方法。首先融合二次雷达信息,建立民航飞行目标DOA变换关系;然后通过航向训练模式,粗估下一时刻各飞行目标DOA,并作为RBFNN的输入;最后构建隐含层中心动态调整的RBFNN,快速准确追踪各飞行目标DOA。实验表明,该方法可以大幅提高空中同时存在的多飞行目标DOA估计精度;结合波束形成技术,可以大幅提高民航地空通信系统的抗干扰能力,提升民航飞行安全水平;在5 dB信噪比条件下,相对基于常规智能天线的民航地空通信系统,抗干扰能力可以提升16 dB。
基金Aeronautical Science F oundation of China !( N o.98E5 1116)
文摘According to the analysis of the very high frequency (VHF) self organized time division multiple access (S TDMA) aviation data link, a new dynamic slot assignment scheme is proposed in this paper, which adopts variable data frame structure and can eliminate the effect of the idle slot on message delay. By using queue theory, the analysis models of the new scheme and previous scheme are presented, and the performance of message delay and that of system throughput are analyzed under two schemes. The simulation results show that the new scheme has a better performance than the previous one in the message delay and system throughput.
基金supported by the ZTE Corporation and University Joint Research Project under Grant No.CON1307100001the National High Technology Research and Development Program of China under Grant No.2013AA013602
文摘In this paper, we discuss several large-scale fading models for different enviromnents. The COST231-Hata model is adapted for air-to-ground modeling. We propose two criteria for air-to- ground channel modelling based on test data derived from field testing in Beijing. We develop a new propagation model that is more suitable for air-to-ground communication that previous models. We focus on improving this propagation model using the field test data.
