X射线空间通信误码率研究

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	X射线空间通信误码率研究
	王律强1
学位类型	硕士
导师	赵宝升
	2015-05-13
学位授予单位	中国科学院研究生院
学位授予地点	北京
学位专业	物理电子学
关键词	X射线通信 Ppm脉冲位置调制泊松噪声模型误码率单光子探测
摘要	基于太空环境的通信技术已经成为衡量世界各国科技实力的关键因素。通信安全在空间环境中尤为重要，传统的微波、激光等通信手段在受到屏蔽干扰及空间天气变化的情况下可靠性大大下降甚至无法通信。而X射线通信可以在电磁屏蔽环境下正常工作，不仅可用于超高速飞机通信和飞行器返回地球时进入黑障区的通信，还将为未来复杂条件下的空天一体化战争提供通信安全保障。 X射线通信这一革命性概念由美国在2007年提出，被称为“下一代新的空间通信方法”，根据NASA提出的空间发展计划，X射线通信和X射线脉冲星导航将于2026年实现太空应用。国内中科院西安光机所2011年首次提出X射线通信的概念，设计了基于栅控X射线发射管与单光子MCP探测器的X射线语音通信演示系统。目前针对X射线空间通信方面的研究皆处于起步阶段，我们搭建了实验装置，开展了X射线调制发射，接收解调等关键技术的研究，为进一步的工程应用奠定了良好基础。本文在调研国内外X射线通信研究与应用发展的基础上，对X射线的空间传输特性及其调制方式进行了研究。其中，基于加性高斯白噪声AWGN信道推导了空间功率传输方程式，以泊松模型为基础构建了X射线空间通信噪声模型，并研究了调制方式对系统误码率误码特性的影响、得出了在不同调制方式下X射线通信系统的误码率理论计算公式，并通过误码率测试实验测得实际误码率数值与理论计算较好的符合：OOK调制方式下系统误码率在10^-4量级,16-PPM调制方式下系统误码率在10^-5量级。通过优化实验设计，提高栅极控制X射线发射源功率、采用自主研制的X射线准直、聚焦系统，有效地减少了X射线空间功率传输损耗，提高了X射线的传输效率。在现有的实验室条件下，完成了10米真空管道X射线通信实验验证。最后根据X射线自由空间损耗以及系统参数，理论计算出现有的这套X射线通信装置在栅极控制X射线脉冲发射源功率为30W时，可以在真空中实现距离为8.7km，速率为1Mbps的X射线通信。
其他摘要	Space development has played an increasing important role in civil and military use. As a result, a great number of researches have been focused on communication security field. The traditional communication methods, such as microwave and laser wave, cannot meet the requirement of space communication at certain extent because of their own restrictions. In contrary, applying X-ray as the carrier can not only realize information transitive against the electromagnetic shielding, but also set the tone for the future space communication field. X-ray communication, known as XCOM, was presented by NASA at 2007 which has been regarded as the next generation space communication method. Besides, the XCOM experiment has been put on their schedule. Domestically, the idea using X-ray as the communication carrier was firstly put forward by our team at 2011. After that, the X-ray vacuum communication demo system which based on the grid-controlled transmitting tube and MCP detector has been implemented. The idea of X-ray communication was tested and verified at the moment when the sound re-generated by the receiver side. The experience accumulated on X-ray transmitting and receiving will play an important role in the future space communication applications. This paper aims at find out how the modulation method influences the communication system performance by fulfilling two different digital pulse modulation methods, OOK and PPM. Specifically, the power function based on several transfer stages is given, as well as the X-ray space noise model based on the Poisson distribution. Finally, we can get the bit error rate specification under different conditions as well as the relationship between optic power and error rate. Currently, the bit error rate can be maintained around 10^-4(OOK) and 10^-5 (PPM) level separately. As for the experiment design, in order to achieve better communication performance, the X-ray focus/ align system which can reduce the power loss dramatically was introduced into this demo system. Based on current condition, sound signal successfully passed the 10 meter vacuum tube. In addition, experiment data accorded with the theory calculation at a large extent. Finally, reasons of restricting the communication system performance are also listed for the future improvement. Currently, the experiment result indicates that X-ray demo system will achieve 8.7km/1Mbps vacuum communication if the tube power large than 30W. In summary, the idea applying X-ray as communication carrier can meet the special requirement of multivariate space environment. Therefore, it is important and meaningful to cultivate this brand new field.
学科领域	电子束器件、x射线管、阴极射线管
语种	中文
文献类型	学位论文
条目标识符	http://ir.opt.ac.cn/handle/181661/23000
专题	研究生部
作者单位	1.西安光机所 2.中国科学院大学
推荐引用方式 GB/T 7714	王律强. X射线空间通信误码率研究[D]. 北京. 中国科学院研究生院,2015.

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X射线空间通信误码率研究.pdf（3089KB）	学位论文		限制开放	CC BY	请求全文