1、 姓 名: 陈建炜 指导教师: 那振宇 信息科学技术学院摘 要我们几乎每天都在进行着通信,通信在我们生活中扮演着极其重要的角色。移动通信已经成为当今通信发展的主流,而无线通信与个人通信在短短的几十年间经历了从模拟通信到数字通信、从OFDM到CDMA的巨大发展,目前又有新的技术的出现,比以CDMA为核心的第三代移动通信技术更加完善,我们称之为“第四代移动通信技术”。第四代移动通信系统计划以OFDM(正交频分复用)为核心技术提供增值服务,它在宽带领域的应用具有很大的潜力。较之第三代移动通信系统,采用多种新技术的OFDM具有更高的频谱利用率和良好的抗多径干扰能力,它不仅可以增加系统容量,更重要的是它
2、能更好地满足多媒体通信要求,将包括语音、数据、影像等大量信息的多媒体业务通过宽频信道高品质地传送出去。纵观通信的发展史,第一代模拟系统仅提供语音服务,不能传输数据;第二代数字移动通信系统的数据传输速率也只有9.6bit/s,最高可达32kbit/s;第三代移动通信系统数据传输速率可达到2Mbit/s;而我们目前所致力研究的第四代移动通信系统的数据传输速率可达到1020Mbit/s。虽然第三代移动通信可以比现有传输速率快上上千倍,但是仍无法满足未来多媒体通信的要求,第四代移动通信系统的提出便是希望能满足提供更大的频宽要求。本文主要研究了OFDM系统中的同步技术。论文首先介绍了 OFDM 的基本原
3、理,主要技术,及同步技术问题。然后,着重对同步技术中的基于数据辅助的同步技术进行了全面的分析及算法研究,通过对其经典算法SC算法及其基础上的改进算法Minn算法及Park算法的研究及仿真,得到了定时性能上,三种算法的优劣性,及Minn算法和Park算法的定时频偏估计方差优劣。关键词:OFDM;同步技术;基于数据辅助的同步技术;SC算法;Minn算法;Park算法ABSTRACTYou, me, him, almost every day during the communication, communication plays a very important role in our live
4、s. Mobile communication has become the mainstream of development, and personal communications and wireless communications in just a few decades has gone from analog communication to digital communication, from CDMA to OFDM great development, but also the emergence of new technologies, more than with
5、 CDMA as the core of the third generation mobile communication technology more sophisticated, which we call the fourth generation mobile communication technology.The fourth generation mobile communication system plans to OFDM (orthogonal frequency division multiplexing) to provide value-added servic
6、es as the core technology, its application in the field of broadband has great potential. Compared with the third generation mobile communication systems, using a variety of new technologies, OFDM has higher spectral efficiency and good anti-multipath interference, it can not only increase system ca
7、pacity, more importantly, it can better meet the needs of multimedia communication requirements, which will include multimedia services voice, data, video and other large amounts of information transmitted via broadband channel with high quality.Throughout the history of the communication, the first
8、 generation analog systems provide voice-only services can transmit data; data transfer rate of the second generation digital mobile communication system is only 9.6bit / s, up to 32kbit / s; third generation mobile communication system data transfer rate up to 2Mbit / s; and we are currently being
9、studied fourth generation mobile communication system dedicated data transmission rate can reach 10 20Mbit / s. Although the third generation mobile communication can be thousands of times faster than the current transmission rate, but still can not meet the future requirements of multimedia communi
10、cations, presented the fourth generation mobile communication system that we hope to provide greater bandwidth to meet the requirements.This paper studies the OFDM system synchronization techniques. Paper first introduces the basic principles of OFDM, the main technical, and synchronization problems
11、. Then, focusing on technology-based synchronous data-aided synchronization technology to conduct a comprehensive analysis and algorithm research, through its classical algorithm SC algorithm and its improved algorithm based on the research and simulation algorithms and Park Minn algorithm, has been
12、 timed performance, the timing of the pros and cons of the three algorithms, and algorithms and Park Minn offset estimation variance of the merits of the algorithm.Keywords: OFDM; synchronization; based on secondary data synchronization technology; SC algorithm; Minn algorithm; Park algorithm目 录第1章
13、绪论11.1引言11.2 OFDM技术的发展及应用11.3 OFDM技术在未来通信中的作用21.4论文研究的主要内容4第2章 OFDM系统原理52.1 OFDM系统基本模型52.2 OFDM的保护间隔和循环前缀62.2.1保护间隔62.2.2循环前缀62.3 OFDM的主要技术72.3.1同步技术72.3.2 训练序列导频及信道估计技术82.3.3信道编码和交织技术82.3.4峰均功率比控制82.3.5均衡技术92.3.6系统仿真参数设计92.4 OFDM技术的优缺点分析92.4.1 OFDM技术主要优点92.4.2 OFDM技术主要缺点10本章小结11第3章 OFDM同步技术123.1 同步
14、技术概述123.2 OFDM系统同步的原理123.3 OFDM系统中的同步要求133.3.1 载波同步133.3.2 符号同步143.3.3 样值同步153.4同步技术的分类15本章小结16第4章 同步算法174.1 SC算法174.2 Minn算法194.3 Park 算法204.4 仿真结果分析22本章小结24总结与展望25参 考 文 献26致 谢28IV第1章 绪论1.1引言进入2l世纪以来,无线通信技术正在以前所未有的速度向前发展。随着用户对各种实时多媒体业务需求的增加和互联网技术的迅猛发展,可以预计,未来的无线通信技术将会具有更高的信息传输速率,为用户提供更大的便利,其网络结构也将发生根本的变化。为了支持更高的信息传输速率和更高的用户移动速度,在下一代的无线通信中必须采用频谱效率更高、抗多径干扰能力更强的新型传输技术。在当前能提供高速率传输的各种无线解决方案中,以正交频分复用(OFDM)为代表的多载波调制技术是最有前途的方案之一。纵观移动通信的发展史,第一代模拟系统仅提供语音服务,不能传输数据;第二代数字移动通信系统的数据传输速率也只有9.6bit/s,最高可32kbit/s;而我们目前所致力研究的第四代移动通信
copyright@ 2008-2022 冰豆网网站版权所有
经营许可证编号:鄂ICP备2022015515号-1