卫星定时接收机的关键技术研究
文献类型：学位论文
| 作者 | 蔡凡 |
| 学位类别 | 博士 |
| 答辩日期 | 2007-05-26 |
| 授予单位 | 中国科学院上海天文台 |
| 授予地点 | 上海天文台 |
| 导师 | 张秀忠 |
| 关键词 | 卫星导航系统 导航卫星接收机 卫星定时接收机 扩频通信 捕获算法 FFT相关法 匹配滤波器法 跟踪算法 锁频环 锁相环 非相干延迟锁定环 环路滤波器 采样频率偏差 非整数倍采样 定时 数字信号处理器 |
| 其他题名 | Key Technologies Research of Satellite Timing Receivers |
| 中文摘要 | The technology of time transmission in many fields such as the scientific research, military and the economic development is widely used. With the development of science and technology, the demand of many fields to time accuracy is more and more high and the range demanding time synchronization is more and more wide. So the timing technology is also rapidly developed. By making use of a radio signal, time transferring and the service of comparing time is widely carried out and Loran-C system is a representative. With the development of space technology, the method of making use of a satellite to transfer and compare time is already commonly applied. Since the satellite time service system has so many advantages, it gradually replaces original time service system in many fields. During the process of satellite timing service, satellite timing receivers affect the timing accuracy. Satellite timing receivers have been improved by the digitization technology, but the high speed of processing signal and the requirement of crystal oscillators that have high performance make receivers expensive. The goal of dissertation is to improve receivers by using the digital signal processing algorithm on the receiver and receiver hardware demand is not raised. The main contents of work are submitted as follows: 1.The algorithms about processing signal in spread spectrum communication system, comparing the signal from satellite navigation system and the signal from the normal spread spectrum communication system, combining carrier recovery algorithms and symbol timing algorithms to select the algorithms of satellite timing receivers, analyzing the hardware structure and timing applying module on satellite timing receiver. 2.The theory base on digital signal processing is introduced in detail. The algorithms on FFT correlation method and matched filter method on searching algorithm, feed-forward tracking algorithm, the frequency locked loop, phase locked loop and non-coherent delay locked loop on the tracking algorithm and the performance about the loop filter are elaborated. The formulas and the simulation on algorithms are also given. 3.Extended research is performed on the basis of the existing algorithms. the feasible way on enhancing timing performance of timing receivers through the technical change of receivers is provided. The research includes that the estimation of the sampling frequency offset is completed by using the code tracking loop and the accuracy of the estimated carrier phase is also enhanced, the difference of many transforming ways from analog domain to digital domain, two running way on the tracking code loop, the method of non-integral sampling is used to enhance the accuracy of local code phase. 4.The actual satellite signal is also used to carry on the confirmation on the algorithms and the above-mentioned algorithms are also confirmed by using the DSP hardware platform. The contents that should simultaneously be paid attention to are described when the algorithms are transformed from Matlab language to C language in the DSP hardware platform. The above-mentioned results provide general theoretical references and a good deal of design examples for the enhancement on the performance of satellite timing receivers. |
| 英文摘要 | 时间传递在科学研究、军事和经济建设等很多领域使用广泛。随着科技的发展，各个领域对时间精度的要求越来越高，要求时间同步的范围越来越广，授时技术也随之得到快速发展。利用无线电信号进行时间传递和比对是一种广泛应用的授时技术，典型代表是罗兰－C系统。随着空间技术的发展，利用卫星进行时间传递和比对的方法已经得到普遍应用，由于卫星授时技术极大扩展了时间同步的工作范围并提高了授时精度，因此卫星授时系统在多个领域逐渐替代原有的授时系统。 在卫星授时过程中，卫星定时接收机的性能影响着定时精度。随着数字化技术的快速发展，卫星定时接收机借助数字化技术极大的提高了性能。但是由于数字化技术对接收机中晶体振荡器以及数字器件处理速度的高要求，使得接收机的成本居高不下。本文旨在通过对接收机涉及的数字信号处理算法的创新使得接收机在提高性能的同时不提高对接收机硬件要求，表现在降低了晶体振荡器的准确度要求以及数字信号的处理速度，提高卫星定时接收机的性价比。本文研究的主要内容如下： 1.扩频通信系统中信号处理算法的相关内容。分析导航卫星信号的特点，比较导航卫星信号与一般扩频信号的异同，结合通用的载波恢复算法和符号定时算法选择卫星定时接收机中相关算法，分析卫星定时接收机的硬件结构和系统中的定时应用单元； 2.详细分析数字信号处理算法涉及的理论基础，对捕获算法中的FFT 相关法和匹配滤波器法、前向跟踪算法、反馈跟踪算法中的锁频环、锁相环、非相干延迟锁定环、多阶环路的性能及环路对应的算法公式等内容进行了理论分析和算法验证； 3.在现有算法基础上做扩展性和补充性研究，为通过对接收机自身的技术改进来提高定时性能提供了可行途径。研究包括利用码跟踪环路完成采样频率偏差的估计以提高载波相位值的准确度、环路滤波器数字转换过程中不同等效方式之间的差异、码跟踪环两种运行方式之间的差异、利用非整数倍采样原理在不提高采样率的前提下提高码相位跟踪的准确度等； 4.利用实际的卫星采样信号和DSP硬件平台对算法进行性能验证和硬件验证，分析在DSP硬件平台上进行算法移植时所应注意的相关内容。 上述方面的研究为提高卫星定时接收机的有关性能提供了丰富的理论依据和设计参考。 |
| 语种 | 中文 |
| 公开日期 | 2011-07-01 |
| 页码 | 200 |
| 源URL | [http://119.78.226.72//handle/331011/14634]  |
| 专题 | 上海天文台_中国科学院上海天文台学位论文 |
| 推荐引用方式 GB/T 7714 | 蔡凡. 卫星定时接收机的关键技术研究[D]. 上海天文台. 中国科学院上海天文台. 2007. |
入库方式： OAI收割
来源：上海天文台
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