【正文】 本科畢業(yè)論文（設(shè)計）題 目 OFDM 關(guān)鍵技術(shù)的研究及其通信系統(tǒng)仿真設(shè)計西南大學(xué)本科畢業(yè)論文IOFDM 關(guān)鍵技術(shù)的研究及其通信系統(tǒng)仿真設(shè)計摘 要：OFDM（Orthogonal Frequency Division Multiplex）意為正交頻分復(fù)用技術(shù)，是多載波（MCM,MultiCarrier Modulation）調(diào)制技術(shù)之一。其主要思想是：利用相互正交的多個子 載波進(jìn)行數(shù)據(jù)的并行傳輸，調(diào)制與解調(diào)由快速傅里葉 變化（FFT ）實(shí)現(xiàn) 。與普通的通信系統(tǒng)相比，OFDM 通信系統(tǒng)的優(yōu)點(diǎn)表現(xiàn)為頻帶利用率高和抗多徑干擾能力強(qiáng)等，因此在很多無線環(huán)境下應(yīng)用廣泛，例如WLAN（無 線局域網(wǎng)）、DVB （數(shù)字視頻廣播）、 HDTV（高清晰度電視）。文章首先介紹了 OFDM 技術(shù)的發(fā)展過程、 應(yīng)用及其關(guān)鍵技術(shù)原理，接著提出了一個基于MATLAB 的 OFDM 通信系 統(tǒng)實(shí)現(xiàn)方案，最后利用 MATLAB 軟件對 OFDM 傳輸性能進(jìn)行仿真并與 16QAM（正交振幅調(diào)制，一種傳統(tǒng)的單載波調(diào)制方式）的性能進(jìn)行了比較，仿真結(jié)果表明OFDM 技術(shù)的抗多徑干擾能較強(qiáng)。關(guān)鍵詞：正交頻分復(fù)用（OFDM） ；MATLAB ；快速傅里葉變換；仿真 西南大學(xué)本科畢業(yè)論文IIStudy On Key Technologies and Design and Simulation of OFDM Communication SystemWang Yang School of Electronics and Information Engineering, Southwest University, Chongqing 400175, ChinaAbstract:Orthogonal Frequency Division Multiplexing(OFDM) is a multicarrier modulation ’s principal thought is that transmitting data simultaneously over multiple equally spaced carrier frequencies and using Fast Fourier Transform processing for modulation and main advantages of OFDM versus other types of modulation are better use of the available bandwidth and better performance in multipath environments,so it has been widely used in highdatarate wireless munication systems,such as wireless localarea works and digital video broadcasting and high distinction television.This paper firstly introduces the development and applications and the theory of OFDM key technologies,then presents a implementation scheme of OFDM munication system based on ,I make use of MATLAB to simulate the transmission performance of order to pare OFDM to a traditional single carrier munication syetem,a Quadrature Amplitude Modulation (16QAM) simulation has also been performed,the result shows that OFDM has better performance in multipath environments .Key words: OFDM；MATLAB ；FFT；Simulation西南大學(xué)本科畢業(yè)論文III目 錄一、緒論 ????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????1二、OFDM 系統(tǒng)的基本原理 ???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????2 正交調(diào)制解調(diào) .....................................................................................................................................2 系統(tǒng)組成 ..............................................................................................................................................5 串并轉(zhuǎn)換 .....................................................................................................................................5 信道編碼 ......................................................................................................................................6 子載波調(diào)制 ..................................................................................................................................6 保護(hù)間隔 ......................................................................................................................................6 OFDM 技術(shù)的優(yōu)點(diǎn) .............................................................................................................................7 抗干擾能力強(qiáng) ..............................................................................................................................7 頻譜利用率高 .............................................................................................................................7 系統(tǒng)結(jié)構(gòu)簡單 ..............................................................................................................................7 OFDM 技術(shù)的缺點(diǎn) .............................................................................................................................7 PAPR（峰均功率比）值較高 ....................................................................................................7 對載波相位噪聲和頻率偏移敏感 ..............................................................................................8 OFDM 的關(guān)鍵技術(shù) .............................................................................................................................8 時域和頻域同步 .........................................................................................................................8 信道估計 ......................................................................................................................................8 降低峰均功率比 ..........................................................................................................................8三、OFDM 系統(tǒng)的 PAPR 抑制算法設(shè)計 ???????????????????????????????????????????????????????????????????????????????????????????????????????????9 OFDM 信號的 PAPR 概述 .................................................................................................................9 降低峰均功率比（PAPR）常用的方法 ............................................................................................9 信號預(yù)畸變技術(shù) .......................................................................................................................10 編碼類技術(shù) ...............................................................................................................................10 概率類技術(shù) ...............................................................................................................................11 SLM、PTS 算法抑制 PAPR 分析 ....................................................................................................11 選擇映射（SLM） ...................................................................................................................11 部分傳輸序列（PTS） ............................................................................................................13 PTS 與 SLM 算法仿真結(jié)果對比與分析 ..................................................................................14四、OFDM 系統(tǒng)的同步算法設(shè)計 ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????15