【正文】 大連海事大學 畢 業(yè) 論 文 二○一 四 年六月 ┊┊┊┊┊┊┊裝┊┊┊┊┊┊┊訂┊┊┊┊┊┊┊線┊┊┊┊┊┊┊ OFDM 通信系統(tǒng)中同步技術研究 專業(yè)班級： 電子信息工程 1 班 姓 名： 陳建煒 指導教師： 那振宇 信息科學技術學院 I 摘 要 我們 幾乎每天都在進行著通信，通信在我們生活中扮演著極其重要的角色。移動通信已經(jīng)成為當今通信發(fā)展的主流，而無線通信與個人通信在短短的幾十年間經(jīng)歷了從模擬通信到 數(shù)字通信、從 OFDM 到 CDMA 的巨大發(fā)展，目前又有新的技術的出現(xiàn)，比以 CDMA 為核心的第三代移動通信技術更加完善，我們稱之為“第四代移動通信技術”。 第四代移動通信系統(tǒng)計劃以 OFDM（正交頻分復用）為核心技術提供增值服務，它在寬帶領域的應用具有很大的潛力。較之第三代移動通信系統(tǒng)，采用多種新技術的 OFDM 具有更高的頻譜利用率和良好的抗多徑干擾能力，它不僅可以增加系統(tǒng)容量，更重要的是它能更好地滿足多媒體通信要求，將包括語音、數(shù)據(jù)、影像等大量信息的多媒體業(yè)務通過寬頻信道高品質(zhì)地傳送出去。 縱觀通信的發(fā)展史，第一代 模擬系統(tǒng)僅提供語音服務，不能傳輸數(shù)據(jù)；第二代數(shù)字移動通信系統(tǒng)的數(shù)據(jù)傳輸速率也只有 ,最高可達 32kbit/s；第三代移動通信系統(tǒng)數(shù)據(jù)傳輸速率可達到 2Mbit/s；而我們目前所致力研究的第四代移動通信系統(tǒng)的數(shù)據(jù)傳輸速率可達到 10～ 20Mbit/s。雖然第三代移動通信可以比現(xiàn)有傳輸速率快上上千倍，但是仍無法滿足未來多媒體通信的要求，第四代移動通信系統(tǒng)的提出便是希望能滿足提供更大的頻寬要求。 本文主要研究了 OFDM 系統(tǒng)中的同步技術。論文首先介紹了 OFDM 的基本原理，主要技術，及同步技術問題。然后 ，著重對同步技術中的基于數(shù)據(jù)輔助的同步技術進行了全面的分析及算法研究，通過對其經(jīng)典算法 SC 算法及其基礎上的改進算法 Minn 算法及 Park 算法的研究及仿真，得到了定時性能上，三種算法的優(yōu)劣性，及 Minn 算法和 Park 算法的定時頻偏估計方差優(yōu)劣。 關鍵詞： OFDM；同步技術；基于數(shù)據(jù)輔助的同步技術； SC 算法； Minn 算法； Park算法 II ABSTRACT You, me, him, almost every day during the munication, munication plays a very important role in our lives. Mobile munication has bee the mainstream of development, and personal munications and wireless munications in just a few decades has gone from analog munication to digital munication, from CDMA to OFDM great development, but also the emergence of new technologies, more than with CDMA as the core of the third generation mobile munication technology more sophisticated, which we call the fourth generation mobile munication technology. The fourth generation mobile munication system plans to OFDM (orthogonal frequency division multiplexing) to provide valueadded services as the core technology, its application in the field of broadband has great potential. Compared with the third generation mobile munication systems, using a variety of new technologies, OFDM has higher spectral efficiency and good antimultipath interference, it can not only increase system capacity, more importantly, it can better meet the needs of multimedia munication 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 munication, the first generation analog systems provide voiceonly services can transmit data。 data transfer rate of the second generation digital mobile munication system is only / s, up to 32kbit / s。 third generation mobile munication system data transfer rate up to 2Mbit / s。 and we are currently being studied fourth generation mobile communication system dedicated data transmission rate can reach 10 ~ 20Mbit / s. Although the third generation mobile munication can be thousands of times faster than the current transmission rate, but still can not meet the future requirements of multimedia munications, presented the fourth generation mobile munication 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. Then, focusing on technologybased synchronous dataaided synchronization technology to conduct a prehensive analysis and algorithm III research, through its classical algorithm SC algorithm and its improved algorithm based on the research and simulation algorithms and Park Minn algorithm, has been 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 IV 目 錄 第 1 章 緒論 .......................................................................................................... 1 引言 .......................................................................................................... 1 OFDM 技術的發(fā)展及應用 ..................................................................... 1 OFDM 技術在未來通信中的作用 ......................................................... 2 論文研究的主要內(nèi)容 .............................................................................. 4 第 2 章 OFDM 系統(tǒng)原理 ..................................................................................... 5 OFDM 系統(tǒng)基本模型 ............................................................................. 5 OFDM 的保護間隔和循環(huán)前綴 ............................................................. 6 保護間隔 ....................................................................................... 6 循環(huán)前綴 ....................................................................................... 6 OFDM 的主要技術 .............................................................................. 7 同步技術 ....................................................................................... 7 訓練序列／導頻及信道估計技術 .............................................. 8 信道編碼和交織技術 ................................................................... 8 峰均功率比控制 ........................................................................... 8 均衡技術 ....................................................................................... 9 系統(tǒng)仿真參數(shù)設 計 ....................................................................... 9 OFDM 技術的優(yōu)缺點分析 ................................................................ 9 OFDM 技術主要優(yōu)點 ............................................................... 9 OFDM 技術主要缺點 ......................................