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摘要:
码分多址(CDMA)的通信体制是大规模卫星星座组网的主要部分，针对星间多通道通信存在多址干扰的情况，对其接收链路建立模型，描述灵敏度与比特能量噪声密度比(BENR)、设备采样信噪比(SNR)的关系，并分析多址干扰和加性白噪声对SNR的影响。在MATLAB仿真不同接收、干扰功率时的BENR与灵敏度，仿真结果表明，信干比(SIR)大于0 dB时，干扰信号对灵敏度影响较小，而维持高灵敏度时可抵抗−6 dB干扰。建立3个发射器和1个接收器的实验平台，由Chipscope、MATLAB软件处理数据，得到符合实际应用需求的接收灵敏度，实验结果表明，SIR大于0 dB时，接收灵敏度可达−107 dBm，高灵敏度下可抵抗−9 dB干扰，误差影响因素为电路噪声。理论分析与实测相符，为实际低轨卫星星座组网的设计奠定了基础。
Abstract:Code division multiple access (CDMA) communication system is the main part of large-scale satellite constellation network. In the case of multiple access interference in multi-channel communication between satellites, the receiving link is modeled. This study elucidates the correlation between bit energy to noise density ratio (BENR) and device received signal-to-noise ratio (SNR), while also investigating the impacts of additive white noise and multiple access interference on SNR. The BENR and sensitivity are simulated in MATLAB with different receiving and interference power. The simulation demonstrates that the interference signal exerts a diminished impact on the sensitivity when the signal-to-interference ratio (SIR) exceeds 0 dB. The receiver can withstand −6 dB interference while maintaining high sensitivity. An experimental platform for three transmitters and one receiver is established. Data is processed by Chipscope and MATLAB software to obtain the received sensitivity that meets the actual application requirements. Experiments show that when SIR is greater than 0 dB, the received sensitivity can reach −107 dBm. The receiver can resist −9 dB interference at high sensitivity. Error is affected by circuit noise. The congruence between the measured data and the theoretical analysis provides a fundamental basis for the development of the real low-orbit satellite constellation network.
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图 5 当前通道接收功率、干扰功率对接收情况的影响
Figure 5. Influence of current channel reception power and interference power on reception
表 1 接收机参数
Table 1. Receiver parameter
$ {f_{\mathrm{s}}}/ {\text{MHz}} $ $ {f_{\mathrm{b}}}/ {\text{MHz}} $ $ {f_{\text{D}}}/ {\text{kHz}} $ $ {T_{{\mathrm{corr}}}}/ {\text{ms}} $ $ {N_{\text{f}}}/ {\text{dBm}} $ $ {L_{\text{w}}}/ {\text{dB}} $ $ {B_{\mathrm{R}}}/ {\text{kHz}} $ $ {f_\Delta }/ {\text{kHz}} $ 40 10.23 115 0.4096 6 0.9 20 1.22 
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表 2 接收链路参数
Table 2. Receiving link parameter
Pt/
dBmLl/
dBLs/
dBLa/
dBGt(α1，β1)/
dBGr(α2，β2)/
dBTs/
Kk/
(dBm·Hz)−1−4 −1 −164 −2 −9 35 300 −228.6
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表 3 不同接收功率和干扰功率时的BER情况
Table 3. BER of different reception power and interference power
$ C/{\text{dBm}} $ $ I/{\text{dBm}} $ $ {\mathrm{BER}} $ −107 −104 0 −107 −99 $3.05 \times {10^{ - 7}}$ −107 −98 $3.66 \times {10^{ - 7}}$ −107 −97 $1.65 \times {10^{ - 6}}$ −107 −94 $1.05 \times {10^{ - 4}}$ −107 −89 $3.82 \times {10^{ - 2}}$ −85 −82 0 −85 −72 $9.76 \times {10^{ - 7}}$ −85 −71 $7.80 \times {10^{ - 6}}$ −85 −70 $3.82 \times {10^{ - 5}}$ −60 −57 0 −60 −47 $3.05 \times {10^{ - 7}}$ −60 −46 $5.73 \times {10^{ - 6}}$ −60 −45 $4.01 \times {10^{ - 5}}$
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[1] 吴树范, 王伟, 温济帆, 等. 低轨互联网星座发展研究[J]. 北京航空航天大学学报, 2024, 50(1): 1-11.WU S F, WANG W, WEN J F, et al. Review on development of LEO Internet constellation[J]. Journal of Beijing University of Aeronautics and Astronautics, 2024, 50(1): 1-11(in Chinese). [2] 姜逸飞, 吴树范, 莫乾坤. 基于大规模卫星星座的6G组网部署及核心网节点动态规划技术[C]//推动网络演进促进应用创新—5G网络创新研讨会. 北京: TD产业联盟, 2021: 408-411.JIANG Y F, WU S F, MO Q K. 6G networking deployment and core network node dynamic planning technology based on large-scale satellite constellation [C]//Proceedings of the Promoting Network Evolution and Promoting Application Innovation-Proceedings of 5G Network Innovation Seminar. Beijing: Telecommunication Development Industry Alliance, 2021: 408-411(in Chinese). [3] 孙建亮, 崔国刚, 周英庆. 发展我国低轨卫星通信星座系统的思考[J]. 通信技术, 2020, 53(9): 2224-2227. doi: 10.3969/j.issn.1002-0802.2020.09.022SUN J L, CUI G G, ZHOU Y Q. Thoughts on development of China’s low-orbit satellite communication constellation system[J]. Communications Technology, 2020, 53(9): 2224-2227(in Chinese). doi: 10.3969/j.issn.1002-0802.2020.09.022 [4] 陈全, 杨磊, 郭剑鸣, 等. 低轨巨型星座网络: 组网技术与研究现状[J]. 通信学报, 2022, 43(5): 177-189. doi: 10.11959/j.issn.1000-436x.2022075CHEN Q, YANG L, GUO J M, et al. LEO mega-constellation network: Networking technologies and state of the art[J]. Journal on Communications, 2022, 43(5): 177-189(in Chinese). doi: 10.11959/j.issn.1000-436x.2022075 [5] 方芳, 吴明阁. 全球低轨卫星星座发展研究[J]. 飞航导弹, 2020(5): 88-92.FANG F, WU M G. Research on the development of global LEO satellite constellation[J]. Aerodynamic Missile Journal, 2020(5): 88-92(in Chinese). [6] XU X Y, WANG C H, JIN Z H. A MAC protocol for distributed satellite network[C]//Proceedings of the IEEE 4th International Conference on Computer and Communication Engineering Technology. Piscataway: IEEE Press, 2021: 327-331. [7] EDMONSON W, GEBREYOHANNES S, DILLION A, et al. Systems engineering of inter-satellite communications for distributed systems of small satellites[C]//Proceedings of the Annual IEEE Systems Conference Proceedings. Piscataway: IEEE Press, 2015: 705-710. [8] TANEN BAUM A S. 计算机网络[M]. 4版. 潘爱民, 译. 北京: 清华大学出版社, 2004.TANENBAUM A S. Computer networks[M]. 4th ed. PAN A M, translated. Beijing: Tsinghua University Press, 2004(in Chinese). [9] 李倩. 低轨卫星通信系统随机接入技术研究[D]. 北京: 北京邮电大学, 2019.LI Q. Research on low-orbit satellite random access technology[D]. Beijing: Beijing University of Posts and Telecommunications, 2019(in Chinese). [10] 韦芬芬, 刘晓旭, 谢继东, 等. 低轨卫星物联网多址接入方式研究[J]. 计算机技术与发展, 2019, 29(5): 116-120. doi: 10.3969/j.issn.1673-629X.2019.05.025WEI F F, LIU X X, XIE J D, et al. Research on multiple access methods for LEO satellite IoT[J]. Computer Technology and Development, 2019, 29(5): 116-120(in Chinese). doi: 10.3969/j.issn.1673-629X.2019.05.025 [11] 黄长文, 朱立东. 低轨卫星系统扩频ALOHA多址接入性能分析[C]//第十三届卫星通信学术年会. 北京: 中国通信学会, 2017: 86-93.HUANG C W, ZHU L D. Performance analysis of spread spectrum ALOHA multiple access for low orbit satellite systems [C]//Proceedings of the 13th Annual Conference on Satellite Communications. Beijing: China Institute of Communications, 2017: 86-93(in Chinese). [12] NGUYEN D T, PARK Y. Performance improvement of optical satellite communications by interleaved IEEE 802.11 LDPC[C]//Proceedings of the Tenth International Conference on Ubiquitous and Future Networks. Piscataway: IEEE Press, 2018: 575-579. [13] CHEN B C, YU L. Design and implementation of LDMA for low earth orbit satellite formation network[C]//Proceedings of the IFIP 9th International Conference on Embedded and Ubiquitous Computing. Piscataway: IEEE Press, 2011: 409-413. [14] 窦中兆, 雷湘. WCDMA系统原理与无线网络优化[M]. 北京: 清华大学出版社, 2009.DOU Z Z, LEI X. WCDMA system principle and wireless network optimization[M]. Beijing: Tsinghua University Press, 2009(in Chinese). [15] MENG E T, BU X Y. Two-dimensional joint acquisition of Doppler factor and delay for MC-DS-CDMA in LEO satellite system[J]. IEEE Access, 2020, 8: 148203-148213. doi: 10.1109/ACCESS.2020.3015754 [16] MENG E T, LI R D, YU J H, et al. Joint CCI mitigation and power control for MC-DS-CDMA in LEO satellite networks[J]. IEEE Internet of Things Journal, 2022, 9(18): 17627-17639. doi: 10.1109/JIOT.2022.3156376 [17] 程鹏仇, 佩亮, 周玥, 等. 802.20 OFDMA系统的上行接入同步算法[J]. 浙江大学学报(工学版), 2008, 42(11): 1894-1899.CHENG P Q, PEI L, ZHOU Y, et al. Uplink access synchronization algorithm for 802.20 OFDMA system[J]. Journal of Zhejiang University (Engineering Edition), 2008, 42(11) : 1894-1899(in Chinese). [18] 谢展腾. LEO卫星CDMA上行链路功率控制算法研究[D]. 哈尔滨: 哈尔滨工业大学, 2017.XIE Z T. The research of CDMA uplink power control algorithms for LEO satellites[D]. Harbin: Harbin Institute of Technology, 2017(in Chinese). [19] ILCEV S D. Analyses of code division multiple access (CDMA) schemes for global mobile satellite communications (GMSC)[J]. TransNav: The International Journal on Marine Navigation and Safety of Sea Transportation, 2020, 14(4): 805-810. doi: 10.12716/1001.14.04.03 [20] NEINAVAIE M, KHALIFE J, KASSAS Z M. Doppler stretch estimation with application to tracking globalstar satellite signals[C]//Proceedings of the IEEE Military Communications Conference. Piscataway: IEEE Press, 2021: 647-651. [21] 朱国富. 扩频体制低轨卫星通信信号捕获与跟踪系统设计[J]. 电讯技术, 2022, 62(5): 576-584. doi: 10.3969/j.issn.1001-893x.2022.05.004ZHU G F. Design of a spread spectrum LEO satellite signal acquisition and tracking system[J]. Telecommunication Engineering, 2022, 62(5): 576-584(in Chinese). doi: 10.3969/j.issn.1001-893x.2022.05.004 [22] 牛翼. 基于5G的低轨卫星系统下行频偏估计算法研究[D]. 西安: 西安电子科技大学, 2020.NIU Y. Research on frequency offset estimation algorithm for downlink of LEO satellite system based on 5G[D]. Xi’an: Xidian University, 2020(in Chinese). [23] KAPLAN E D. GPS原理与应用[M]. 2版. 寇艳红, 译. 北京: 电子工业出版社, 2012.KAPLAN E D. Principles and applications of GPS[M]. 2nd ed. KOU Y H, translated. Beijing: Electronic Industry Press, 2012(in Chinese). -
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