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Study on the Two-Sides Matching between Multiple Rovers and Multiple Orbiters in Mars Relay Communications

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China Communications 2020年第7期17卷 80-93页

作者： Peng Wan yafeng zhan Space center Tsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing 100084China

In Mars relay communications,if multiple rovers and multiple orbiters are visible with each other at the same time in certain contact,there are not only issues concerned with the multiple rovers’access to single orbiter,but also the issues concerned with the optimal access orbiter selection for each rover,which is a complex multi-objective decision-making problem relating to the resource allocation optimizations in deep-space *** this paper,the two-sides matching between multiple rovers and multiple orbiters in Mars relay communications is proposed based on the access preferences,taking the two-sides combined fitness of preferences and the single-side evaluation equilibrium as the optimization objectives,which utilizes the parallel capsule operations architecture encapsulated with several one-to-many two-sides matching algorithms to obtain stable multiple access matching *** results show that,our method performs better than the CCSDS Proximity-1 protocols,and could achieve the effective utilization of deep space communication network resources.

关键词： matching utilize concerned

Solar system interplanetary communication networks:architectures, technologies and developments

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Science China(Information Sciences) 2018年第4期61卷 19-44页

作者： Peng WAN yafeng zhan Xiaohan PAN Space Center Tsinghua University

With the development of deep space exploration technologies, main space agencies all over the world are working hard to develop the solar system interplanetary communication networks(SSICN). SSICN is a perspective communication networking system characterized by high data rate, high intelligent and perfect interconnection, which could provide the deep-space mission control and scientific application with the convenient, reliable and secure data transmission services. Following the introduction of future deep space exploration prospect, this paper analyzes the similarities and differences for three networks, terrestrial internet, near Earth space networks and SSICN, then discusses the key technologies and research trends of SSICN in details, and finally proposes the suggestions for the construction of future Chinese SSICN.

关键词： deep space exploration SSICN system architecture physical transmission network access up-layer application time synchronization

Networked TT&C for Mega Satellite Constellations:A Security Perspective

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China Communications 2022年第9期19卷 58-76页

作者： yafeng zhan Guanming Zeng Xiaohan Pan Beijing National Research Center for Information Science and Technology Beijing 100084China Department of Electronic Engineering Tsinghua UniversityBeijing 100084China

Satellite constellations are promising in enabling the global ***,the increasing constellation size also complicates tracking,telemetry and command(TT&C)*** groundbased and space-based approaches have encountered significant obstacles due to,e.g.,the limited satellite visible arc and long transmission *** the fast development of intersatellite communications,synergy among multiple connected satellites can be exploited to facilitate TT&C system *** leads to networked TT&C,which requires much less predeployed infrastructures and even performs better than traditional TT&C *** this paper,we elaborate system characteristics of networked TT&C compared with traditional ground-based and spacebased TT&C,and propose the unique security challenges and opportunities for networked TT&C,which includes secure routing and trust ***,since networked TT&C is a novel scenario with few relevant researches,we first investigate the current researches on secure routing and trust mechanisms for traditional terrestrial and satellite networks,and then accordingly deliver our security perspectives considering the system characteristics and security requirements of networked TT&C.

关键词： mega-constellation TT&C network security routing trust mechanisms

Review of channel models for deep space communications

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Science China(Information Sciences) 2018年第4期61卷 61-72页

作者： Xiaohan PAN yafeng zhan Peng WAN Jianhua LU Space Center Tsinghua University

This paper presents a comprehensive review of channel models for deep space *** on the characteristics of environment, deep space channels can be divided into three kinds, i.e.,near Earth link, interstellar link and near planet link. The modeling for different kinds of channels are summarized respectively, and some simulation results are provided in this paper. In addition, according to the development trend of deep space communications, optical wave will become an important carrier in the future. Therefore, deep space optical communication is also briefly introduced. Finally, challenges of deep space channel modeling are pointed out and future research direction is also discussed.

关键词： deep space communication channel modeling microwave communication optical communication deep space exploration

A Frequency Domain Based Signal Combining Method for Distributed Antenna Arraying

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China Communications 2019年第8期16卷 176-184页

作者： Chaowei Duan yafeng zhan Qian Kong Space Center Tsinghua UniversityBeijing 100080China Beijing National Research Center for information Science and Technology (BNRist) Beijing 100080China Guangzhou Haige Communications Group Incorporated Company Guangzhou 510000China

Distributed antenna arraying is a promising technology for weak signal reception. The received signals from different antennas are aligned and combined to improve the receiving signal-to-noise ratio(SNR). However, the combining performance is serious degraded by the difference of sampling frequency between antennas. In this paper, a frequency domain based signal combining method is proposed to solve this problem. The unaligned sampled data in time domain of the received signals are transformed to frequency domain using fast Fourier transform(FFT). The received signals can be aligned in frequency domain when their spectrum resolutions are the same. Therefore the received signals with the same total sampling time can be aligned and combined in frequency domain and then the combined signal is recovered using inverse fast Fourier transform(IFFT). Numerical simulations with two typical modulation types, i.e., PSK and PCM/BPSK/PM, prove the validity and robustness of this method.

关键词： weak signal reception distributed antenna arraying signal combining fast fourier transform

A High Data-Rate Software Defined Radio Receiver Suited for FPGA Platforms

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China Communications 2009年第1期6卷 73-77页

作者： Chen Zhijun zhan yafeng Lu Jianhua Department of Electronic Engineering Tsinghua University Beijing China

Although Alternate Parallel Receiver (APRX) could effectively improve the maximum demodulating rate of the receiver, its frequency domain processing module consumes a large amount of multiplication units when the number of parallel input channels is large, making it unsuitable for use on FPGA software defi ned radio platforms. This paper proposes an optimization scheme by introducing partitioned convolution and exploring the spectrum characteristic of the APRX input data, reducing the usage of multipliers greatly. After the optimization, the number of real multipliers used in the frequency-domain processing module of the 16-ary APRX is reduced from about 576 to 68, with little performance loss. This optimized APRX is fairly suitable for FPGA software defi ned radio platform applications.

关键词： FPGA APRX optimization partitioned convolution

Performance Analysis of the Packet-Based PNT Service in NGSO Broadband Satellite Communication Systems

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中国通信:英文版 2023年第9期20卷 247-259页

作者： Xi Chen Qihui Wei yafeng zhan Linling Kuang National Information Science and Technologies Research Center Tsinghua UniversityBeijing100084China Department of Electronic Engineering Tsinghua UniversityBeijing100084China

Providing alternative PNT service to GNSS-challenged users will be an important function of next-generation NGSO broadband satellite communication ***,a packet-based PNT service architecture in NGSO broadband systems is proposed in which a primary satellite and selected assistant satellites work together to provide PNT service to requesting *** positioning performance bounds are mathematically formulated by rigorously analyzing the bounds constrained by different *** are conducted on different configurations of Walker Delta MEO constellations and Walker Star LEO constellations for corroboration,revealing the following:(1)Both MEO and LEO constellations achieve sub-meter-level positioning precision given enough satellites.(2)Compared to the GNSS Doppler-based velocity estimation method,the position advance based velocity estimation algorithm is more precise and applicable to the PNT service in NGSO broadband systems.(3)To provide PNT service to users in GNSS-challenged environments,the primary and each assistant satellite need only∼0.1‰of the time of one downlink beam.

关键词： 6G non-terrestrial network NGSO satellite positioning performance analysis

A NEW ALGORITHM FOR MAIN CARRIER ACQUISITION IN DEEP SPACE COMMUNICATIONS

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Journal of Electronics(China) 2011年第2期28卷 169-173页

作者： zhang Ruyuan zhan yafeng Lu Jianhua Department of Electronic Engineering Tsinghua University Beijing 100084 China Space Center Tsinghua University Beijing 100084 China

Compared with common near space satellite Telemetry,Telecommand,and Communication(TT&C),deep space TT&C presents a more challenging environment such as long distance,very low Signal to Noise Ratio(SNR).How to acquire main carrier exactly becomes a hot focus for deep space *** there emerged some main carrier acquisition algorithms,but they all require high SNR and small modulation *** this paper,we develop a new acquire *** we use the spectral energy center algorithm to shorten the original sequence,filter out some noise and make the spectral more *** we adopt the spectral symmetry algorithm to make full use of the whole spectrum information,and utilize FFT to reduce computation *** results show that our algorithm can acquire main carrier successfully under large modulation index and get good performance with low Carrier to Noise Ratio(CNR).

关键词： Deep space Telemetry Telecommand and Communication(TT&C) Main carrier acqui-sition Low Carrier to Noise Ratio(CNR) Modulation index

A GEO Satellite Position and Beam Features Estimation Method Based on Beam Edge Positions

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Journal of Communications and Information Networks 2019年第4期4卷 87-94页

作者： Zixuan Ren Wei Li Jin Jin yafeng zhan Ting Li School of Aerospace Engineering Tsinghua UniversityBeijing 100084China The State Radio Monitoring Center Beijing 100041China Beijing National Research Center for Information Science and Technology Beijing 100084China School of Information Science and Technology Tsinghua UniversityBeijing 100084China

Constrained by orbital configuration and spectrum sharing,non-geostationary orbit(NGEO)satellites may be interfered when they are in the beam range of geostationary orbit(GEO)***,it is difficult for NGEO operators to determine the signal ***,we propose a method to locate the GEO signal source and estimate beam features,including beam pointing azimuth,elevation,and beamwidth,by the beam edge *** transform this estimation problem into two optimization problems by minimizing the estimation error,and solve both of them through a multi-variable joint iteration method with acceptable computation *** results show that when NGEO satellites pass through the beam twice,the longitude estimation error is about 0.01 degree,and the estimation results will be more and more accurate as the number of passing times ***,the proposed method is also effective when there are kilometer-level errors in beam edge positions.

关键词： GEO satellite position beam feature estimation method beam edge position optimization problem multi-variable joint iteration