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LoS MIMO Transmission for leo satellite Communication Systems

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China Communications 2022年第10期19卷 180-193页

作者： Lingxuan Li Tingting Chen Wenjin Wang Xiaohang Song Li You Xiqi Gao National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China Vodafone Chair Mobile Communications Systems Technische Universität Dresden01062 DresdenGermany

To provide global service with low latency, the broadband low earth orbits (leo) satellite constellation based communication systems have become one of the focuses in academic and industry. To allow for wideband access for user links, the feeder link of leo satellite is correspondingly required to support high throughput data communications. To this end, we propose to apply line-of-sight (LoS) multiple-input multiple-output (MIMO) transmission for the feeder link to achieve spatial multiplexing by optimizing the antenna arrangement. Unlike the LoS MIMO applications for static scenarios, the movement of leo satellites make it impractical to adjust the optimal antenna separation for all possible satellite positions. To address this issue, we propose to design the antenna placement to maximize the ergodic channel capacity during the visible region of the ground station. We first derive the closed-form probability distribution of the satellite trajectory in visible region. Based on which the ergodic channel capacity can be then calculated numerically. The antenna placement can be further optimized to maximize the ergodic channel capacity. Numerical results verify the derived probability distribution of the satellite trajectory, and show that the proposed LoS MIMO scheme can significantly increase the ergodic channel capacity compared with the existing SISO one.

关键词： LoS MIMO leo satellite ergodic channel capacity Beyond 5G

A Safe and Reliable Routing Mechanism of leo satellite Based on SDN

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Computers, Materials & Continua 2020年第7期64卷 439-454页

作者： Chao Guo Juan Guo Chanjuan Yu Zhaobin Li Cheng Gong Abdul Waheed Department of Electronics and Communication Engineering Beijing Electronic Science and Technology InstituteBeijing100070China Vocational and Technical College Guilin University of Electronic TechnologyBeihai536000China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing100083China University of Management Technology Lahore55300Pakistan

satellite networks have high requirements for security and data processing *** order to improve the reliability of the network,software-defined network(SDN)technology is introduced and a central controller is set in the *** to the characteristics of global perspective,control data separation,and centralized control of SDN,the idea of SDN is introduced to the design of the satellite network *** a result,satellite nodes are only responsible for data transmission,while the maintenance of the links and the calculation of routes are implemented by the *** the massive leo satellite network based on SDN,a state evaluation decision routing mechanism is *** designed mechanism monitors the status of the entire network effectively and reduces the on-board load on the satellite *** best routing decision is made under the comprehensive consideration of the current and historical status of each inter-satellite link between Low Earth Orbit(leo)satellite network *** calculation and storage requirements are controlled within a reasonable *** on the curve parameter transmission fuzzy encryption algorithm,a safe and reliable condition assessment decision routing mechanism(CADRM)is *** ensures that the personal information of the leo satellite network can be transmitted safely and *** experimental simulation results show the improvement of network throughput,the reduction of packet loss rate and the enhancing of network reliability.

关键词： Route leo satellite SDN state assessment inter-satellite link

Covert leo satellite Communication Aided by Generative Adversarial Network Based Cooperative UAV Jamming

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China Communications 2024年第9期21卷 27-39页

作者： Shi Jia Li Xiaomeng Liao Xiaomin Tie Zhuangzhuang Hu Junfan School of Communication Engineering Xidian UniversityXi’an 710071China School of Information and Communications National University of Defense TechnologyWuhan 410073China

In this paper,we study the covert performance of the downlink low earth orbit(leo)satellite communication,where the unmanned aerial vehicle(UAV)is employed as a cooperative *** maximize the covert rate of the leo satellite transmission,a multi-objective problem is formulated to jointly optimize the UAV’s jamming power and *** practical consideration,we assume that the UAV can only have partial environmental information,and can’t know the detection threshold and exact location of the eavesdropper on the *** solve the multiobjective problem,we propose the data-driven generative adversarial network(DD-GAN)based method to optimize the power and trajectory of the UAV,in which the sample data is collected by using genetic algorithm(GA).Simulation results show that the jamming solution of UAV generated by DD-GAN can achieve an effective trade-off between covert rate and probability of detection errors when only limited prior information is obtained.

关键词： covert communication generative adversarial network leo satellite UAV jammer

Adaptive Tracking for Beam Alignment Between Ship-Borne Digital Phased-Array Antenna and leo satellite

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Journal of Communications and Information Networks 2019年第3期4卷 60-70页

作者： Qin Chen Yuying Xu Chunyi Song Zhiwei Xu Institute of Marine Electronic and Intelligent System Ocean CollegeZhejiang UniversityZhoushan 316021China Key Laboratory of Ocean Observation-Imaging Testbed of Zhejiang Province Zhoushan 316021China

In mobile satellite communication networks employing digital beam forming technology,beam alignment imposes great influence on link quality and network *** to complex coupling motion by low earth orbit(leo)satellite and ship,direction of arrival(DOA)of target satellite varies rapidly and *** then causes difficulty to accurately track the *** this work,an adaptive tracking algorithm is proposed by exploiting advantages of flexible parameter configuration of digital phased-array *** alignment process basically consists of observation and *** the observation stage,two-dimensional(2-D)multiple signal classification(MUSIC)is applied by the ship-borne digital phased-array antenna to estimate beam direction of satellite;in the tracking stage,an extended Kalman filter(EKF)based adaptive tracking is designed to achieve fast and accurate *** proposed adaptive tracking improves performance by adaptively estimating tracking parameters in EKF *** estimation results are then used as feedback to adaptively adjust digital phased-array antenna parameters to improve estimation accuracy of *** results under sea state 5 show that the proposed tracking algorithm improves tracking accuracy and stability over conventional ones.

关键词： satellite communication on-the-move adaptive tracking alignment of antenna leo satellite shipborne communication digital phased-array antenna

Simulation of the Impacts of Single leo satellite Orbit Parameters on the Distribution and Number of Occultation Events

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Geo-Spatial Information Science 2006年第1期9卷 13-17页

作者： XU Xiaohua LI Zhenghang LUO Jia Institute of satellite Application School of Geodesy and Geomatics Wuhan University 129 Luoyu Road Wuhan 430079 China

Focusing on carrying out GPS occultation observat io ns with a receiver set on leo satellite, this paper develops the leo orbit simul ation system based on which the occultation events can be simulated taking into account the geometric relationship of the satellites and the field of view of th e receiver antenna. In this paper, the impacts of 4 types of leo orbit parameter s including argument of latitude (AOL), right ascension of ascending node (RAAN) , orbit height and orbit inclination on the distribution and number of occultati on events observed with a single leo satellite are discussed through simulat ion and some conclusions are drawn.

关键词： leo satellite GPS occultation orbit parameters

OTFS Enabled NOMA for MMTC Systems over leo satellite

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ZTE Communications 2021年第4期19卷 63-70页

作者： MA Yiyan MA Guoyu WANG Ning ZHONG Zhangdui AI Bo Beijing Jiaotong University Beijing 100044China Zhengzhou University Zhengzhou 450001China Peng Cheng Laboratory Shenzhen 518000China

As a complement of terrestrial networks,non-terrestrial networks(NTN)have ad⁃vantages of wide-area coverage and service *** NTN is potential to play an impor⁃tant role in the 5G new radio(NR)and *** enable the massive machine type communi⁃cations(mMTC),the low earth orbit(leo)satellite is preferred due to its lower transmission delay and path ***,the leo satellite may generate notable Doppler shifts to de⁃grade the system ***,orthogonal time frequency space(OTFS)modulation has been *** provides the opportunity to allocate delay Doppler(DD)domain resourc⁃es,which is promising for mitigating the effect of high ***,as the leo satellite constellation systems such as Starlink are thriving,the space spectrum resources have become increasingly ***,non-orthogonal multiple access(NOMA)is considered as a candidate technology to realize mMTC with limited spectrum *** this paper,the ap⁃plication of OTFS enabled NOMA for mMTC over the leo satellite is *** leo satellite based mMTC system and the OTFS-NOMA schemes are ***,the challenges of applying OTFS and NOMA into leo satellite mMTC systems are ***⁃nally,the potential technologies for the systems are investigated.

关键词： mMTC leo satellite OTFS NOMA

satellite-Ground Link Planning Method for leo satellite Navigation Augmentation Network in the case of Multiple Ground Stations

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Satellite-Ground Link Planning Method for LEO Satellite Navi...

Precise orbit determination of leo satellite using onboard BDS-3 B1C/B2a observations

第十三届中国卫星导航年会

作者： Yanghongyi Kuang Xianqing Yi Zhenwei Hou Science and Technology on Information Systems Engineering Laboratory National University of Defense Technology National Innovation Institute of Defense Technology Academy of Military Science

Aiming at satellite-ground link planning problem for leo satellite navigation augmentation network in the case of multiple ground stations, we proposes a planning method based on graph theory. First, according to the boundary assumption and essential analysis of satellite-ground link planning problem for leo satellite navigation augmentation network in the case of multiple ground stations, we establishes a corresponding mathematical model. Then, based on the need to quickly solve the approximate optimal solution of the above model, a graph theory-based satellite-ground link planning method is proposed, and the performance of the solution result of this method is theoretically proved. Finally, the simulation results verify the effectiveness of the method actually applied to the leo satellite navigation augmentation network in the case of multiple ground stations.

关键词： multiple ground stations leo satellite navigation augmentation satellite-ground link planning

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Precise orbit determination of LEO satellite using onboard B...

Method of GNSS Security Augmentation Based on leo satellite

第十三届中国卫星导航年会

作者： Youcun Wang Qile Zhao Kecai Jiang GNSS Research Center Wuhan University

The precise orbit determination（POD） of low earth orbit（leo） satellites is always a hotspot topic in the field of satellite geodesy. Current gravity field determination, satellite altimetry, and remote sensing measurement depend crucially on the precise orbits of the spacecraft. BeiDou global navigation satellite system（BDS-3） is officially completed in 2020 and offers positioning, navigation, and timing（PNT） service for global users. The onboard BDS measurements from leo satellites can be used for leo POD and served as an effective supplement for BDS tracking geometry. In this study, the BDS-3 observations with B1 C and B2 a signals of HY-2 D spacecraft are employed for reduced-dynamic POD. For superior orbit quality, the extended analytical model for solar radiation pressure（SRP） is used for leo POD, and in-flight calibration of the leo receiver antenna is carried out to improve the orbit precision. Two weeks of onboard BDS-3 observation were used to assess the BDS-based POD performance. For HY-2 D satellite based on BDS-3 instruments, the capability of continuous tracking is at the global level, and almost all the epochs can have 5-7 usable BDS satellites. The average RMS of the phase residual from the reduced-dynamic POD is 6.5 mm, and that of pseudorange residual is 1.28 m. The internal precision for the entire arc is in good agreement. Moreover, an orbit self-consistency of 0.94 cm, 0.76 cm, and 0.49 cm is displayed in the along-track, cross-track, and radial directions, respectively. The average consistency for the reduced-dynamic orbit is at the 1.33 cm position RMS level. BDS-3-based leo orbit determination with the uncertainty of about 2 cm is obtained through independent satellite Laser Ranging（SLR） validation. These results could be used for the Chinese subsequent leo satellite equipped with a BDS-3 receiver.

关键词： BDS-3 leo satellite Precise orbit determination B1C/B2a Orbit precision

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Method of GNSS Security Augmentation Based on LEO Satellite