A medium earth orbit （MEO） tracking and data relay satellite system （TDRSS） constellation scheme for China is proposed. This system consists of MEO satellite constellation, inter-satellite links （ISLs） and terre...A medium earth orbit （MEO） tracking and data relay satellite system （TDRSS） constellation scheme for China is proposed. This system consists of MEO satellite constellation, inter-satellite links （ISLs） and terrestrial gateway station, which can provide continuous bidirectional data transmission links between low altitude spacecrafls and the terrestrial gateway station in China. Theoretical analysis and simulation results indicate that the proposed constellation can cover the global low altitude space sphere and earth surface of China continuously, and has a preferable practical perspective.展开更多
The satellite constellation classes, which are suitable for the medium earth orbit tracking and data relay satellite system （MEO-TDRSS） of China, are investigated. On the basis of the functionality and the traffic d...The satellite constellation classes, which are suitable for the medium earth orbit tracking and data relay satellite system （MEO-TDRSS） of China, are investigated. On the basis of the functionality and the traffic distribution characteristic of MEO-TDRSS, the coverage performance and inter-satellite link properties of four different constellation schemes are compared by simulations. Simulation results indicate that the rosette and common-track constellations, whose satellites are distributed on the celestial sphere more uniformly, are appropriate for the implementation of MEO-TDRSS of China.展开更多
While adopting an elevation-over-azimuth architecture by an inter-satellite linkage antenna of a user satellite, a zenith pass problem always occurs when the antenna is tracing the tracking and data relay satellite （...While adopting an elevation-over-azimuth architecture by an inter-satellite linkage antenna of a user satellite, a zenith pass problem always occurs when the antenna is tracing the tracking and data relay satellite （TDRS）. This paper deals with this problem by way of, firstly, introducing movement laws of the inter-satellite linkage to predict the movement of the user satellite antenna followed by analyzing the potential pass moment and the actual one of the zenith pass in detail. A number of specific orbit altitudes for the user satellite that can remove the blindness zone are obtained. Finally, on the base of the predicted results from the movement laws of the inter-satellite linkage, the zenith pass tracing strategies for the user satellite antenna are designed under the program guidance using a trajectory preprocessor. Simulations have confirmed the reasonability and feasibility of the strategies in dealing with the zenith pass problem.展开更多
A hybrid switching node structure with light and microwave links is proposed, which is applicable to the future data relay satellite systems, aiming at the development trend of coexistence of light- link and microwave...A hybrid switching node structure with light and microwave links is proposed, which is applicable to the future data relay satellite systems, aiming at the development trend of coexistence of light- link and microwave-link in the future. An experimental system for the light and microwave hybrid switching node based on wavelength selective optical switches (WSS) and optical transceiver modules, is established. It is shown by our experiment that this hybrid switching node can realize the dynamic bandwidth allocation and wavelength routing while the bit error rate of light link is less than 10?12, which provides a method for solving the hybrid switching problem of light-link and microwave-link on the future data relay satellite systems.展开更多
分析了跟踪与数据中继卫星系统（trucking and data relay satellite system，TDRSS）高速反向链路数据组2（data group2，DG2）传输带宽和功率受限的特点，针对其在高信息传输速率条件下提高抗干扰能力的需求，提出了多进制扩频抗干扰...分析了跟踪与数据中继卫星系统（trucking and data relay satellite system，TDRSS）高速反向链路数据组2（data group2，DG2）传输带宽和功率受限的特点，针对其在高信息传输速率条件下提高抗干扰能力的需求，提出了多进制扩频抗干扰方案。在研究了多进制扩频技术在高速率传输下抗干扰性能的基础上，结合该技术对高速链路进行建模，并根据模型进行了数字与半实物仿真。仿真结果证明了多进制扩频抗干扰技术能在有限的传输带宽内大大提高高速反向链路抗干扰性能。展开更多
为了在跟踪与数据中继卫星系统(TDRSS)中实现码分多址(CDMA)应用,需要完成多用户检测(MUD)及码分多址干扰(MAI)抑制。采用减性多级迭代对消算法,在数字信号处理芯片中完成信号再生、延时校正、时域相减对消,可以完成至少12通道的多用户...为了在跟踪与数据中继卫星系统(TDRSS)中实现码分多址(CDMA)应用,需要完成多用户检测(MUD)及码分多址干扰(MAI)抑制。采用减性多级迭代对消算法,在数字信号处理芯片中完成信号再生、延时校正、时域相减对消,可以完成至少12通道的多用户检测,并能将多址干扰抑制至最小1 d B以内。该算法可作为通用MUD算法的有效补充,并能应用于各类非最优的CDMA系统中,具有迭代级数可选、通道扩展性强、工程实现性好的优点。展开更多
With continuous expansion of satellite applications,the requirements for satellite communication services,such as communication delay,transmission bandwidth,transmission power consumption,and communication coverage,ar...With continuous expansion of satellite applications,the requirements for satellite communication services,such as communication delay,transmission bandwidth,transmission power consumption,and communication coverage,are becoming higher.This paper first presents an overview of the current development status of Low Earth Orbit(LEO)satellite constellations,and then conducts a demand analysis for multi-satellite data transmission based on LEO satellite constellations.The problem is described,and the challenges and difficulties of the problem are analyzed accordingly.On this basis,a multi-satellite data-transmission mathematical model is then constructed.Combining classical heuristic allocating strategies on the features of the proposed model,with the reinforcement learning algorithm Deep Q-Network(DQN),a two-stage optimization framework based on heuristic and DQN is proposed.Finally,by taking into account the spatial and temporal distribution characteristics of satellite and facility resources,a multi-satellite scheduling instance dataset is generated.Experimental results validate the rationality and correctness of the DQN algorithm in solving the collaborative scheduling problem of multi-satellite data transmission.展开更多
基金National Natural Science Foundation of China (No. 60372013)
文摘A medium earth orbit （MEO） tracking and data relay satellite system （TDRSS） constellation scheme for China is proposed. This system consists of MEO satellite constellation, inter-satellite links （ISLs） and terrestrial gateway station, which can provide continuous bidirectional data transmission links between low altitude spacecrafls and the terrestrial gateway station in China. Theoretical analysis and simulation results indicate that the proposed constellation can cover the global low altitude space sphere and earth surface of China continuously, and has a preferable practical perspective.
基金the National Natural Science Foundation of China (60372013)
文摘The satellite constellation classes, which are suitable for the medium earth orbit tracking and data relay satellite system （MEO-TDRSS） of China, are investigated. On the basis of the functionality and the traffic distribution characteristic of MEO-TDRSS, the coverage performance and inter-satellite link properties of four different constellation schemes are compared by simulations. Simulation results indicate that the rosette and common-track constellations, whose satellites are distributed on the celestial sphere more uniformly, are appropriate for the implementation of MEO-TDRSS of China.
文摘While adopting an elevation-over-azimuth architecture by an inter-satellite linkage antenna of a user satellite, a zenith pass problem always occurs when the antenna is tracing the tracking and data relay satellite （TDRS）. This paper deals with this problem by way of, firstly, introducing movement laws of the inter-satellite linkage to predict the movement of the user satellite antenna followed by analyzing the potential pass moment and the actual one of the zenith pass in detail. A number of specific orbit altitudes for the user satellite that can remove the blindness zone are obtained. Finally, on the base of the predicted results from the movement laws of the inter-satellite linkage, the zenith pass tracing strategies for the user satellite antenna are designed under the program guidance using a trajectory preprocessor. Simulations have confirmed the reasonability and feasibility of the strategies in dealing with the zenith pass problem.
文摘A hybrid switching node structure with light and microwave links is proposed, which is applicable to the future data relay satellite systems, aiming at the development trend of coexistence of light- link and microwave-link in the future. An experimental system for the light and microwave hybrid switching node based on wavelength selective optical switches (WSS) and optical transceiver modules, is established. It is shown by our experiment that this hybrid switching node can realize the dynamic bandwidth allocation and wavelength routing while the bit error rate of light link is less than 10?12, which provides a method for solving the hybrid switching problem of light-link and microwave-link on the future data relay satellite systems.
文摘分析了跟踪与数据中继卫星系统（trucking and data relay satellite system，TDRSS）高速反向链路数据组2（data group2，DG2）传输带宽和功率受限的特点，针对其在高信息传输速率条件下提高抗干扰能力的需求，提出了多进制扩频抗干扰方案。在研究了多进制扩频技术在高速率传输下抗干扰性能的基础上，结合该技术对高速链路进行建模，并根据模型进行了数字与半实物仿真。仿真结果证明了多进制扩频抗干扰技术能在有限的传输带宽内大大提高高速反向链路抗干扰性能。
文摘为了在跟踪与数据中继卫星系统(TDRSS)中实现码分多址(CDMA)应用,需要完成多用户检测(MUD)及码分多址干扰(MAI)抑制。采用减性多级迭代对消算法,在数字信号处理芯片中完成信号再生、延时校正、时域相减对消,可以完成至少12通道的多用户检测,并能将多址干扰抑制至最小1 d B以内。该算法可作为通用MUD算法的有效补充,并能应用于各类非最优的CDMA系统中,具有迭代级数可选、通道扩展性强、工程实现性好的优点。
基金supported by the National Natural Science Foundation of China(Nos.42271391,62006214,and 42101439)the Joint Funds of Equipment Pre-Research and Ministry of Education of China(No.8091B022148)+1 种基金the 14th Five-Year Pre-Research Project of Civil Aerospace of China,the Hubei Excellent Young and Middle-Aged Science and Technology Innovation Team Plan Project(No.T2021031)the Open Research Project of Hubei Key Laboratory of Intelligent GeoInformation Processing(No.KLIGIP-2022-B09).
文摘With continuous expansion of satellite applications,the requirements for satellite communication services,such as communication delay,transmission bandwidth,transmission power consumption,and communication coverage,are becoming higher.This paper first presents an overview of the current development status of Low Earth Orbit(LEO)satellite constellations,and then conducts a demand analysis for multi-satellite data transmission based on LEO satellite constellations.The problem is described,and the challenges and difficulties of the problem are analyzed accordingly.On this basis,a multi-satellite data-transmission mathematical model is then constructed.Combining classical heuristic allocating strategies on the features of the proposed model,with the reinforcement learning algorithm Deep Q-Network(DQN),a two-stage optimization framework based on heuristic and DQN is proposed.Finally,by taking into account the spatial and temporal distribution characteristics of satellite and facility resources,a multi-satellite scheduling instance dataset is generated.Experimental results validate the rationality and correctness of the DQN algorithm in solving the collaborative scheduling problem of multi-satellite data transmission.
