多载波QAM调制环境下同步技术的实现
文献类型：学位论文
| 作者 | 李春红 |
| 学位类别 | 博士 |
| 答辩日期 | 2005 |
| 授予单位 | 中国科学院声学所 |
| 授予地点 | 中国科学院声学所 |
| 关键词 | 多载波QAM调制 符号定时同步 载波相位恢复 帧同步 |
| 其他题名 | Realization of Synchronization Technology for Multi-carrier QAM Modulation |
| 中文摘要 | 数字通信与模拟通信相比，尽管具有占用频带宽、传输容量受限的缺点，但同时也具有信号可以中继再生，避免干扰积累，易于实现保密通信，便于各种数字业务的交换及设备的集成化等优点，因而得到了快速发展。QAM调制是一种频带利用率很高的调制技术。这对于频带和带宽受限的移动通信系统来说具有很大的吸引力。多载波是解决提高传输速率和抗干扰能力的另一个有效办法，在有限的带宽内，将信道分成多个子信道，同时传输多路信号，大大提高通信系统的传输效率。同步通信作为数字通信的一个重要组成部分，"同步"是保证信息可靠传输的前提。为此，需要在接收端建立和发送端有一定频率、相位关系的载波同步、位同步、帧同步甚至于是网同步。其中载波同步主要用于相干解调时，在接收端提供一个与接受到的载波信号同帧同相的本地载波；在位同步用于确定甸个码元的起止时刻以便在恰当的时刻进行信号的采样、判决、再生；帧同步用于给出每帧信号的"开头"和"结尾"的时刻。在多载波QAM调制技术的环境下，同步技术是一个研究难点。本文介绍了多载波QAM调制技术的环境下同步技术的实现方案及硬件实现方法。提出了采用最大功率法估计信道的时间延迟；利用最大似然方法估计载波相位参数；在帧同步的实现方案中，首先对！咳的结构作了定义；然后在传输过程中考虑两种情况的帧同步：初始化过程的帧同步和数据正常传输过程时的帧同步；设计并建立了一个基于TIDSP（TMS3205416）芯片的通用数字信号处理硬件平台。利用DSP软件编程，实现了DSP软件编程。实现了同步技术方案的工程算法。 |
| 英文摘要 | Synchronous communication, as an important branch of digital communication, is a prerequisite of carrying on the information transmission. So carrier synchronization, symbol synchronization, frame synchronization and network synchronization are established in the receiving end, which has relation with frequency and phase of the sending end. Among them the carrier synchronization is used to provide the local carrier signal in the receiving end, which has the same frequency and phase with the received carrier signal when it used to relevant demodulation mainly. And the symbol synchronization is used to make sure the start and stop position of every symbol, so the sampling, judging and regenerating signal are carried on at appropriate moment. The frame synchronization is used for providing the moment of beginning and ending of the every frame signal. The QAM modulates technology has very great appeal to mobile communication system of which the frequency band and bandwidth are limited, QAM is a kind of modulation technology holding very high utilization ratio of frequency band. Multi-carrier is another effective way of enhancing transfer speed, which divides the channel into many sub channels and transmits multiplex signals simultaneously in the limited bandwidth. So the transmission efficiency of the communication system is greatly raised. Synchronous communication, as an important branch of digital communication, is a prerequisite of carrying on the information transmission. So carrier synchronization, symbol synchronization, frame synchronization and network synchronization are established in the receiving end, which has relation with frequency and phase of the sending end. Among them the carrier synchronization is used to provide the local carrier signal in the receiving end, which has the same frequency and phase with the received carrier signal when it used to relevant demodulation mainly. And the symbol synchronization is used to make sure the start and stop position of every symbol, so the sampling, judging and regenerating signal are carried on at appropriate moment. The frame synchronization is used for providing the moment of beginning and ending of the every frame signal. Frame synchronization is used for providing the moment of beginning and ending of the every frame signal. Under the environment of using the multi-carrier QAM modulation technology, synchronization technology is a difficult point of research. Synchronization technology's realizing scheme and hardware implementation method is introduced in this paper based on the multi-carrier QAM technology. Two algorithms are emphatically introduced, that one is maximum power algorithm, which performs estimating symbol timing, and the other is maximum likelihood algorithm, which performs carrier phase recovery. In the frame synchronization algorithm, the frame structure is defined. For completing the frame synchronization, two conditions should be considered, that one is course of initialization, and the other is course of transmission. In the end, a platform of general digital signal proceccing based on TI DSP(TMS3205416) has been designed and foundated, as a result, the engineering algorithm of synchronization has been concluted by DSP software programming. |
| 语种 | 中文 |
| 公开日期 | 2011-05-07 |
| 页码 | 58 |
| 源URL | [http://159.226.59.140/handle/311008/974]  |
| 专题 | 声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文 |
| 推荐引用方式 GB/T 7714 | 李春红. 多载波QAM调制环境下同步技术的实现[D]. 中国科学院声学所. 中国科学院声学所. 2005. |
入库方式： OAI收割
来源：声学研究所
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