Abstract：With the increase in the number of non-geostationary orbit (NGSO) satellite systems, the interference between NGSO satellite systems using the same frequency has become increasingly prominent. Because of the large number and time-vary relative motion of NGSO systems, the traditional interference analysis methods and evaluation index, which are aiming for geostationary orbit (GSO) satellite systems, are no longer suitable for NGSO scene. Based on the relevant rules and recommendations of the International Telecommunication Union, this paper establishes a mathematical model of the interference analysis for non-geostationary satellite systems, and proposes a link angle probabilistic analysis method for satellite constellation interference analysis. Aiming at the complicated features such as the large number of satellites consisting of NGSO constellations and the changing temporal and spatial relationship, the scheme of NGSO constellation global interference analysis is given. The probability calculation method of harmful interference between satellite constellations and the index of satellite constellation usability are proposed. On the basis of the actual satellite network data, taking OneWeb system and O3b system as an example, the range of the link angle of the interference protection between the satellite systems is calculated. The angle of the satellite link, the interference state and the probability distribution of the availability ratio on a global scale are given, provides a means for NGSO constellation interference analysis.
靳瑾, 李娅强, 张晨, 匡麟玲, 晏坚. 全球动态场景下非静止轨道通信星座干扰发生概率和系统可用性[J]. 清华大学学报（自然科学版）, 2018, 58(9): 833-840.
JIN Jin, LI Yaqiang, ZHANG Chen, KUANG Linling, YAN Jian. Occurrence probability of co-frequency interference and system availability of non-geostationary satellite system in global dynamic scene. Journal of Tsinghua University(Science and Technology), 2018, 58(9): 833-840.
[1] PARK C S, KANG C G, CHOI Y S, et al. Interference analysis of geostationary satellite networks in the presence of moving non-geostationary satellites[C]//Proceedings of the 20102nd International Conference on Information Technology Convergence and Services. Cebu, Phillippines:IEEE, 2010:1-5. [2] KOBAYASHI H, SHINONAGA H, ARAKI N, et al. Study on interference between non-GSO MSS gateway station and GSO FSS earth station under reverse band operation[C]//Proceedings of the 10th International Conference on Digital Satellite Communications. Brighton, UK:IET, 1995:282-289. [3] GAM H, OH D S, AHN D S. Effective method to assess the impact of interference between non-GSO system and fixed service[C]//Proceedings of 2009 International Workshop on Satellite and Space Communications. Tuscany, Italy:IEEE, 2009:206-209. [4] FORTES J M P, MALDONADO J E A. Protection of fixed service receivers from the interference produced by the non-geostationary satellites in a fixed satellite service network:A statistical interference analysis[J]. International Journal of Satellite Communications, 2002, 20(1):15-27. [5] FORTES J M P, SAMPAIO-NETO R, MALDONADO J E A. An analytical method for assessing interference in interference environments involving NGSO satellite networks[J]. International Journal of Satellite Communications, 1999, 17(6):399-419. [6] ITU-R. Analytical method for estimating interference between non-geostationary mobile-satellite feeder links and geostationary fixed-satellite networks operating co-frequency and codirectionally:ITU-R S.1324[S]. Geneva:ITU, 1997. [7] ITU-R. Artical 21 in radio regulations[R]. Geneva:ITU, 2016. [8] SHARMA S K, CHATZINOTAS S, OTTERSTEN B. In-line interference mitigation techniques for spectral coexistence of GEO and NGEO satellites[J]. International Journal of Satellite Communications and Networking, 2016, 34(1):11-39. [9] VATALARO F, CORAZZA G E, CAINI C, et al. Analysis of LEO, MEO, and GEO global mobile satellite systems in the presence of interference and fading[J]. IEEE Journal on Selected Areas in Communications, 1995, 13(2):291-300. [10] DESLANDES V, TRONC J, BEYLOT A L. Analysis of interference issues in integrated satellite and terrestrial mobile systems[C]//Proceedings of the 11th Signal Processing for Space Advanced Satellite Multimedia Systems Conference. Cagliari, Italy:IEEE, 2010:256-261. [11] ITU-R. Coordination of the L5 satellite network in IFIC2809[DB]. (2015-08-12)[2017-05-10]. https://www.itu.int/sns/ific61/ific2809.zip. [12] ITU-R. Coordination of the O3b-A satellite network in IFIC2644[DB]. (2009-05-19)[2017-05-10]. https://www.itu.int/sns/ific6/ific2644.zip. [13] ITU-R. Coordination of the O3b-B satellite network in IFIC2693[DB]. (2011-05-03)[2017-05-10]. https://www.itu.int/sns/ific61/ific2693.zip. [14] ITU-R. Apportionment of the allowable error performance degradations to fixed-satellite service (FSS) hypothetical reference digital paths arising from time invariant interference for systems operating below 30 GHz:ITU-R S.1432-1[S]. Geneva:ITU, 2006.
2018, Vol. 58 
