Adaptive dwell scheduling is essential to achieve full performance for a simultaneous multi-beam radar system.The dwell scheduling for such a radar system considering desired execution time criterion is studied in thi...Adaptive dwell scheduling is essential to achieve full performance for a simultaneous multi-beam radar system.The dwell scheduling for such a radar system considering desired execution time criterion is studied in this paper.The primary objective of this model is to achieve maximum scheduling gain and minimum scheduling cost while adhering to not only time,aperture,and frequency constraints,but also electromagnetic compatibility(EMC)constraint.The dwell scheduling algorithm is proposed to solve the above optimization problem,where several separation points are set on the timeline,so that each separator divides the scheduling interval into two sides.For the two sides,the dual-side time pointers are introduced,which move from the separator to both ends of the scheduling interval.The dwell tasks are analyzed in sequence at each analysis point based on their two-level synthetical priority.These tasks are then executed simultaneously by sharing the whole aperture under various constraints to accomplish multiple tasks concurrently.The above process is respectively conducted at each separator,and the final scheduling result is the one with the minimal cost among all.Simulation results prove that the proposed algorithm can achieve real-time dwell scheduling and outperform the existing algorithms in terms of scheduling performance.展开更多
Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.Howeve...Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.However,the traditional SWIPT transmitter usually suffers from cross-talk distortion caused by the high peak-to-average power ratio of the input signal and the reduction of power amplifier efficiency.This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface(ASTCM).High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface.We demonstrate the feasibility of the proposed method through theoretical derivations and experimental verification,which is therefore believed to have great potential in wireless communications and the IoT devices.展开更多
Beamforming is one of the most important part of signal processing in sonar system.Traditionally, in the analogue system the bearing direction is steered by rotating some kind of time-delay compensator, which is usual...Beamforming is one of the most important part of signal processing in sonar system.Traditionally, in the analogue system the bearing direction is steered by rotating some kind of time-delay compensator, which is usually made by machanic-clectronic components. But,there exists a fixed bias error in target tracking due to the application of discrete tapped delay line. With the development of digital sonar the multi-beamforming technique is extensively used in various sonar systems. In these systems each beam has a fixed bearing direction. The precise DOA (Direction Of Arrival) estimation of the target becomes more important in sonar design. General speaking, if the sampling frequency is high enough, it is possible to get arbitrary number of beams, which steer in any designated direction. But a hardware tradeoff must be taken account for a good designer. In order to obtain higher target spatial resolution and reduce the hardware cost, it is necessary to make some kind of interpolation algorithm in post beamforming. It is proved that in the most interested situation the behavior of directivity function in the neighborhood of main lobe depends on the sinc function and zero order Bessel function. The multi-beam data is actually the spatial sampling to these function. Based on the principle of parabolic interpolation, a simple but high accuracy beam interpolation technique is presented in this paper. The theoretical basis of three-point and five-point interpolation algorithm is described. As an example, the line array and circle array of hydrophones are illustrated to explain this algorithm. The results of system simulation show that the method proposed in this paper has good agreement with the theory. It can be used to improve the behavior of the directivity function and enhance the multi-target resolving ability of digital sonar system. It is also possible to use this technique to implement ATT (Automatic TargetTracking) in real time.展开更多
基金supported in part by the National Natural Science Foundation of China(Nos.61771095 and 62031007).
文摘Adaptive dwell scheduling is essential to achieve full performance for a simultaneous multi-beam radar system.The dwell scheduling for such a radar system considering desired execution time criterion is studied in this paper.The primary objective of this model is to achieve maximum scheduling gain and minimum scheduling cost while adhering to not only time,aperture,and frequency constraints,but also electromagnetic compatibility(EMC)constraint.The dwell scheduling algorithm is proposed to solve the above optimization problem,where several separation points are set on the timeline,so that each separator divides the scheduling interval into two sides.For the two sides,the dual-side time pointers are introduced,which move from the separator to both ends of the scheduling interval.The dwell tasks are analyzed in sequence at each analysis point based on their two-level synthetical priority.These tasks are then executed simultaneously by sharing the whole aperture under various constraints to accomplish multiple tasks concurrently.The above process is respectively conducted at each separator,and the final scheduling result is the one with the minimal cost among all.Simulation results prove that the proposed algorithm can achieve real-time dwell scheduling and outperform the existing algorithms in terms of scheduling performance.
基金supported by the Program of Song Shan Laboratory(included in the management of Major Science and Technology Program of Henan Province)(Nos.221100211300-03 and 221100211300-02)the National Key Research and Development Program of China(No.2018YFA0701904)+5 种基金the National Natural Science Foundation of China(Nos.62288101,61731010,62201139,and U22A2001)the 111 Project(No.111-2-05)the Jiangsu Province Frontier Leading Technology Basic Research Project(No.BK20212002)the Fundamental Research Funds for the Central Universities(No.2242022k60003)the National Natural Science Foundation(NSFC)for Distinguished Young Scholars of China(No.62225108)the Southeast University-China Mobile Research Institute Joint Innovation Center(No.R207010101125D9).
文摘Simultaneous wireless information and power transfer(SWIPT)architecture is commonly applied in wireless sensors or Internet of Things(IoT)devices,providing both wireless power sources and communication channels.However,the traditional SWIPT transmitter usually suffers from cross-talk distortion caused by the high peak-to-average power ratio of the input signal and the reduction of power amplifier efficiency.This paper proposes a SWIPT transmitting architecture based on an asynchronous space-time-coding digital metasurface(ASTCM).High-efficiency simultaneous transfer of information and power is achieved via energy distribution and information processing of the wireless monophonic signal reflected from the metasurface.We demonstrate the feasibility of the proposed method through theoretical derivations and experimental verification,which is therefore believed to have great potential in wireless communications and the IoT devices.
文摘Beamforming is one of the most important part of signal processing in sonar system.Traditionally, in the analogue system the bearing direction is steered by rotating some kind of time-delay compensator, which is usually made by machanic-clectronic components. But,there exists a fixed bias error in target tracking due to the application of discrete tapped delay line. With the development of digital sonar the multi-beamforming technique is extensively used in various sonar systems. In these systems each beam has a fixed bearing direction. The precise DOA (Direction Of Arrival) estimation of the target becomes more important in sonar design. General speaking, if the sampling frequency is high enough, it is possible to get arbitrary number of beams, which steer in any designated direction. But a hardware tradeoff must be taken account for a good designer. In order to obtain higher target spatial resolution and reduce the hardware cost, it is necessary to make some kind of interpolation algorithm in post beamforming. It is proved that in the most interested situation the behavior of directivity function in the neighborhood of main lobe depends on the sinc function and zero order Bessel function. The multi-beam data is actually the spatial sampling to these function. Based on the principle of parabolic interpolation, a simple but high accuracy beam interpolation technique is presented in this paper. The theoretical basis of three-point and five-point interpolation algorithm is described. As an example, the line array and circle array of hydrophones are illustrated to explain this algorithm. The results of system simulation show that the method proposed in this paper has good agreement with the theory. It can be used to improve the behavior of the directivity function and enhance the multi-target resolving ability of digital sonar system. It is also possible to use this technique to implement ATT (Automatic TargetTracking) in real time.
文摘基于编码正交频分复用的数字音频广播(DAB)具有鲁棒性高和激光唱盘(CD)音质等优良性能。带内同频道(IBOC)制式的DAB能够在已有的模拟广播频道内同播模拟和数字两种信号,完全兼容现有的模拟接收机,以较低成本实现向全数字化 DAB的平滑过渡。作者论述了 FM IBOC DAB的频谱分析,综述了混合模式 FM IBOC DAB的发射(接收)机的基本结构和感知音频编码、前向纠错编码、OFDM、第一邻频道干扰消除、时间延迟分集和音频混合等关键技术,提出了发展我国的 IBOC DAB的一些建议。
