【作者】 罗彤；

【导师】 胡渝；

【作者基本信息】 电子科技大学 ， 光学， 2005， 博士

【摘要】 星间光通信是极具前景的通信方式。由于星上环境复杂,通信距离遥远,而可靠的光通信对跟瞄精度要求很高,所以,捕获,跟踪和瞄准(ATP)技术成为实现星间光通信的关键和难题。跟踪技术是实现整个ATP功能的核心,捕获是建立通信链路的前提。因此,对星间光通信ATP中的捕获和跟踪技术研究非常必要。 本文在简要介绍星间光通信及ATP技术的概念、关键技术、发展现状和趋势、以及各子系统组成及相关技术的基础上,对星间光通信ATP中的捕获技术,跟踪技术,精跟踪控制算法和精跟踪演示系统进行了比较深入的研究。 在星间光通信捕获技术研究方面,本文对捕获方案,捕获过程,捕获方式以及扫描方式进行了阐述。深入分析了捕获概率,提出了覆盖概率下扫描点重叠因子的计算方法。推导了在不同阈噪比和信噪比下的探测概率以及最佳捕获阈值电流。并对捕获链路进行了仿真研究。 在星间光通信跟踪技术研究方面,本文在跟踪误差统计模型研究的基础上,重点分析了跟踪误差对系统性能的影响,得出了在给定突发误差概率情况下,光束束宽与跟踪精度的优化关系;以及在IM/DD方式下,光束束宽、跟踪误差与误码率的优化关系,并分析计算了在不同跟踪误差和光束束宽情况下,系统给定误码率所需的最小发射功率。这些结论为星间光通信系统参数优化设计提供了依据。论文阐述了星间光通信系统的跟踪误差源,重点对探测器误差,卫星平台振动及振动抑制方法进行了研究。在星间光通信跟踪系统结构研究方面,论文对复合轴控制系统的结构,类型和工作原理进行了阐述,并分析了复合轴控制系统的性能。 本文首次将现代鲁棒控制理论应用于星间光通信精跟踪控制器的设计中。论文阐述了鲁棒控制的基本概念,相关理论和研究内容。对系统的鲁棒稳定和鲁棒性能进行了详细讨论,并介绍了H_∞/μ综合方法。根据精跟踪系统模型,利用H_∞/μ理论进行鲁棒控制器设计,并分析了精跟踪系统的鲁棒稳定性和鲁棒性能。论文对精跟踪探测器CCD帧频对系统跟踪带宽的影响也进行了分析说明。在此基础上,建立了星间光通信跟踪系统模型,并对其进行了仿真研究。更多还原

【Abstract】 Optical intersatellite communications will be an important element in the future satellite communication infrastructure. An optical intersatellite communication system must be capable of high accuracy line of sight under disturbance in satellite environment for reliable communications, as a consequence, the acquisition, tracking and pointing (ATP) are critical and difficult issues in optical intersatellite communications. Tracking system is the kernel of implementing ATP functions, and rapid acquisition is basic requirement in establishing the optical links. So, it is necessary for researching acquisition and tracking techniques in optical intersatellite communications.Based on the brief introduction of the concepts, key techniques, development trend, and subsystem of optical intersatellite communications and ATP techniques, the acquisition and tracking technique, fine tracking control algorithm and fine tracking demonstration system are studied in this dissertation.Firstly, after discussing the acquisition scenarios, acquisition method, and scan pattern in acquisition technique of optical intersatellite communication, the acquisition probability is studied. Through analyzing the scan area coverage probability, the overlap factor calculation method is proposed. By this method, the acquisition probability can be increased. Based on the analysis of detection probability, the acquisition optimum threshold current and detection probability are obtained under the condition of different threshold-to-noise ratio and signal-to-noise ratio. Then, acquisition link simulation is presented.Secondly, the tracking error and the control structure of tracking technique in optical intersatellite communications are studied with emphasis. On the basis of the statistic model of tracking error, that tracking error effects on system performance is studied. In which, the optimum relationship between beam width and tracking error is obtained with given the burst error of system. And that, the optimum relationship between beam width, tracking error and bit error rate in IM/DD communication is also proposed. Based on this optimum relationship, the minimum transmitter power which can satisfy the optical link budget requirement is calculated. In addition, the source of tracking error, such as, detector error, satellite platform vibration and vibration rejection methods are analyzed. In tracking system structure research, the更多还原