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Autonomous mission reconstruction during the ascending flight of launch vehicles under typical propulsion system failures

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Chinese Journal of Aeronautics 2022年第6期35卷 211-225页

作者： zhengyu song Yin LIU Yong HE Cong WANG China Academy of Launch Vehicle Technology Beijing 100076China Beijing Institute of Astronautical Systems Engineering Beijing 100076China Beijing Aerospace Automatic Control Institute Beijing 100854China

In recent years, Chinese Long March(LM) launchers have experienced several launch failures, most of which occurred in their propulsion systems, and this paper studies Autonomous Mission Reconstruction(AMRC) technology to alleviate losses due to these failures. The status of the techniques related to AMRC, including trajectory and mission planning, guidance methods,and fault tolerant technologies, are reviewed, and their features are compared, which reflect the challenges faced by AMRC technology. After a brief introduction about the failure modes of engines that can occur during flight, and the fundamentals of trajectory planning and joint optimization of the target orbit and flight path, an AMRC algorithm is proposed for geostationary transfer orbit launch missions. The algorithm evaluates the residual performance onboard, and plans new objectives and corresponding flight path by iterative guidance mode or segmented state triggered optimization methods in real-time. Three failure scenarios that have occurred during previous LM missions are simulated to check the robustness of the algorithm: imminent explosion risk of the boosters’ engines, thrust drop during the first stage of flight, and being unable to start the engine during the second stage. The payloads would fall from space according to the current design under these conditions, but they were saved with the AMRC algorithm in the simulations, which allowed the rocket to get into the target orbit as intended or the payloads were deployed in other orbits without crashing. Although spaceflight can be very unforgiving, the AMRC algorithm has the potential to avoid the total loss of a launch mission when faced with these kinds of typical failures.

关键词： Autonomous mission reconstruction Closed-loop guidance State triggered indices Rescue orbits Launch vehicles

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Powered-Coast-Powered Guidance Recon-guration Method of Launch Vehicle with Thrust Drop Fault

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Guidance, Navigation and Control 2022年第1期2卷 51-76页

作者： Cong Wang zhengyu song Beijing Aerospace Automatic Control Institute Beijing 100854 P.R.China China Academy of Launch Vehicle Technology Beijing 100076 P.R.China

This paper describes the study of a powered-coast-powered guidance recon¯guration(PCPGR)method used to solve the autonomous rescue problem for the mission pro¯le of a launch vehicle with a coasting phase when the thrust drop fault occurs in the¯rst powered phase(FPP)of the¯nal stage.We¯rst described the constraints of the¯nal stage and the construction of the PCP guidance problem.Then we evaluated the adaptability of the guidance recon¯guration(GR)o®line with numerical optimization by adjusting the constraints of the FPP,the coast phase,and the second powered phase.To determine the fault state set where the rocket can enter the prescribed target orbit through the GR initiate,we proposed a Newton method-based rapid replanning method of the transfer orbit that transforms the complex multi-°ight phase trajectory planning problem into a feasible transfer orbit search problem to produce a fast solution onboard.Combined with the adaptive adjustment of the coasting time and the iterative guidance mode,we realized the autonomous online rescue of the payload.The simulation results showed that the proposed method achieved a reliable and rapid solution and improved a launch vehicle's adaptability to a thrust drop fault.

关键词： Launch vehicle guidance recon¯guration powered-coast-powered thrust drop fault

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Pilot Contamination Elimination in Massive MIMO Systems with an Improved Time-Shifted Scheme

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Journal of Beijing Institute of Technology 2020年第1期29卷 16-22页

作者： Yuanyuan Hao zhengyu song Institute of Telecommunication Satellite China Academy of Space TechnologyBeijing 100094China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China

Pilot contamination can bring up a grave impairment in the performance of massive multiple-input multiple-output(MIMO)systems.In this paper,an improved time-shifted pilot scheme is proposed to reduce the pilot contamination,where orthogonal pilots are employed in the same group to eliminate the residual intragroup interference existing in the original time-shifted pilot scheme.Meanwhile,the rigorous closed-form expressions of both downlink and uplink transmission rates with a finite number of antennas are derived,and it is shown that the intra-group interference can be completely eliminated by the proposed scheme.Simulation results demonstrate that both downlink and uplink transmission rates are significantly improved by employing the proposed scheme.

关键词： massive multiple-input multiple-output(MIMO) pilot contamination time-shifted pilot

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Exploiting Spectral-Energy Efficiency Tradeoff with Fairness in Non-Orthogonal Multiple Access Systems

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Journal of Beijing Institute of Technology 2019年第2期28卷 336-343页

作者： zhengyu song Xin Sun School of Electronic and Information Engineering Beijing Jiaotong University

The spectral efficiency(SE)and energy efficiency(EE)tradeoff while ensuring rate fairness among users in non-orthogonal multiple access(NOMA)systems is investigated.In order to characterize the SE-EE tradeoff with rate fairness,a multi-objective optimization(MOO)problem is first formulated,where the rate fairness is represented with theα-fair utility function.Then,the MOO problem is converted into a single-objective optimization(SOO)problem by the weighted sum method.To solve the converted non-convex SOO problem,we apply sequential convex programming,which helps to propose a general power allocation algorithm to realize the SE-EE tradeoff with rate fairness.We prove the convergence of the proposed algorithm and the convergent solution satisfies the KKT conditions.Simulation results demonstrate the proposed power allocation algorithm can achieve various levels of rate fairness,and higher fairness results in degraded performance of SE-EE tradeoff.A pivotal conclusion is reached that NOMA systems significantly outperform orthogonal multiple access systems in terms of SE-EE tradeoff with the same level of rate fairness.

关键词： non-orthogonal multiple access(NOMA) energy efficiency(EE) spectral efficiency(SE) rate fairness power allocation

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Improved Delay Priority Resource Scheduling with Low Packet Loss Rate for MBMS in LTE Systems

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Journal of Beijing Institute of Technology 2020年第3期29卷 339-344页

作者： Xin Sun Yuan Yang zhengyu song School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China

An improved delay priority resource scheduling algorithm with low packet loss rate for multimedia broadcast multicast service(MBMS)in long term evolution(LTE)systems is proposed in this paper.Real-time services in LTE systems require lower delay and packet loss rate.However,it is difficult to meet the QoS requirements of real-time services using the current MBMS resource scheduling algorithm.The proposed algorithm in this paper jointly considers user delay information and real-time channel conditions.By introducing the user delay information,the lower delay and fairness of users are guaranteed.Meanwhile,by considering the channel conditions of users,the packet loss rate can be effectively reduced,improving the system throughput.Simulation results show that under the premise of ensuring the delay requirements of real-time services,the proposed algorithm achieves a lower packet loss rate compared to other existing algorithms.Furthermore,it can achieve a good balance between system throughput and user fairness.

关键词： multimedia broadcast multicast service(MBMS) quality of service resource scheduling real time services

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Prospects of sea launches for Chinese cryogenic liquid-fueled medium-lift launch vehicles

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Chinese Journal of Aeronautics 2021年第1期34卷 424-437页

作者： zhengyu song Zhifeng XIE Limin QIU Dalin XIANG Jinglin LI China Academy of Launch Vehicle Technology Beijing 100076China Beijing Institute of Astronautical Systems Engineering Beijing 100076China College of Energy Engineering Zhejiang UniversityHangzhou 310027China

This paper introduces the sea-launch technology of a cryogenic liquid-fueled medium-lift rocket.It first reviews the current state of sea launch technology,and then gives a brief introduction of China’s New Generation Medium-lift Launch Vehicle(NGMLV).The innovations in the NGMVL,such as responsive test and launch control,a H3 launch model,and unmanned operations,provide convenience for sea launches.Based on these innovations,this paper proposes a sea launch scheme,including the system configuration,test and launch processes,and an improved adaptive design for the rocket.Then,the launch platform is discussed in detail,which integrates the functions of sea transportation,assembly and test,as well as technical and launch areas.The layout and function divisions,fluid filling,gas supply and distribution systems,and lossless storage technology of LH2 are described in order.This breakthrough in sea launch technology will enable China to launch medium and large satellites and constellations‘both on land and sea’,especially into low-inclination Low-Earth Orbits(LEOs),and it allows China to remain competitive in the fast-paced space industry.

关键词： Autonomous operations Launch platform Launch vehicles Liquid hydrogen storage Sea launches

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Spectrum-Efficient and Fair Resource Scheduling for MBMS in LTE Systems

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Journal of Beijing Institute of Technology 2019年第4期28卷 777-782页

作者： Xin Sun Honghui Ye zhengyu song School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China

An improved spectrum-efficient and fair resource scheduling algorithm for multimedia broadcast multicast service(MBMS)in long term evolution(LTE)systems is proposed in this paper.By jointly considering the channel conditions of all the users,the average packet loss rate,and the fairness of users in the MBMS group,the transmission data rate of the MBMS group is first selected according to the link adaptation and the average packet loss rate of users.Then,the resource blocks are allocated to MBMS groups according to the scheduling priority.Such a resource scheduling algorithm further balances the system throughput and user fairness.Theoretical analysis and simulation results show that the proposed algorithm can achieve a good tradeoff between system throughput and user fairness in comparison with traditional scheduling algorithms.

关键词： multimedia broadcast multicast service(MBMS) resource scheduling system throughput user fairness packet loss rate

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非正交多址接入的同步透射反射智能超表面信号增强算法

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北京邮电大学学报 2024年第1期47卷 7-12页

作者：侯天为李洁王俊宋政育孙昕北京交通大学电子信息工程学院北京100044

针对传统智能超表面无法透射信号的问题,利用同步透射反射智能超表面,提出了一种基于非正交多址接入的信号增强算法。同步透射反射智能超表面具有全向性的特点,可同时服务两侧的非正交多址接入用户。所提算法将同步透射反射智能超表面... 详细信息

针对传统智能超表面无法透射信号的问题,利用同步透射反射智能超表面,提出了一种基于非正交多址接入的信号增强算法。同步透射反射智能超表面具有全向性的特点,可同时服务两侧的非正交多址接入用户。所提算法将同步透射反射智能超表面的信号与通信信号相干叠加,利用黎曼共轭梯度算法求解优化问题,理论上可大幅增强用户的信号功率,降低中断概率,提高频谱效率性能。由仿真结果可知,与不使用同步透射反射智能超表面相比,随机相位的同步透射反射智能超表面可以提高约3.6 bit/(s·Hz)的系统频谱效率。利用黎曼共轭梯度算法优化后,可进一步提高约2.3 bit/(s·Hz)的系统频谱效率,该结果验证了所提算法的优越性。

关键词：同步透射反射智能超表面非正交多址接入信号增强算法中断概率通信速率

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Downlink Resource Allocation with Multi-Objective Optimization in OFDMA Systems

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Journal of Harbin Institute of Technology(New Series) 2015年第1期22卷 68-72页

作者： zhengyu song Shujuan Hou Siliang Wu School of Information and Electronics Beijing Institute of Technology

A downlink radio resource allocation algorithm is proposed for orthogonal frequency division multiple access( OFDMA) systems. The resource allocation problem about system throughput and user fairness is formulated based on the multi-objective optimization theory. Then the optimality conditions are derived,according to which a joint subcarrier and power allocation algorithm is proposed. The simulation results show that the proposed algorithm can dynamically achieve arbitrary levels of compromise between throughput and fairness by adjusting the weighting coefficient,outperforming some static algorithms. In comparison,the classic maximum rate algorithm( MRA),max-min algorithm and proportional fairness( PF) algorithm can only achieve tradeoff in a certain level and are all special cases of the proposed algorithm.

关键词： OFDMA resource allocation multi-objective optimiza

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习近平文化思想的鲜明特征与原创性贡献

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郑州铁路职业技术学院学报 2024年第1期36卷 5-7页

作者：宋正昱河南省社会科学院河南郑州450000

科学性、人民性、实践性、发展性是习近平文化思想的鲜明特征,这些特性使习近平文化思想具有与时俱进的强大生命力。深刻领会习近平文化思想的鲜明特征与原创性贡献,有利于全面理解、把握这一思想,使我们切实肩负起建设社会主义文化强... 详细信息

科学性、人民性、实践性、发展性是习近平文化思想的鲜明特征,这些特性使习近平文化思想具有与时俱进的强大生命力。深刻领会习近平文化思想的鲜明特征与原创性贡献,有利于全面理解、把握这一思想,使我们切实肩负起建设社会主义文化强国的历史使命。

关键词：习近平文化思想中国特色原创性贡献

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