【正文】 mission 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(jiǎn)單 ..............................................................................................................................7 OFDM 技術(shù)的缺點(diǎn) .............................................................................................................................7 PAPR（峰均功率比）值較高 ....................................................................................................7 對(duì)載波相位噪聲和頻率偏移敏感 ..............................................................................................8 OFDM 的關(guān)鍵技術(shù) .............................................................................................................................8 時(shí)域和頻域同步 .........................................................................................................................8 信道估計(jì) ......................................................................................................................................8 降低峰均功率比 ..........................................................................................................................8三、OFDM 系統(tǒng)的 PAPR 抑制算法設(shè)計(jì) ???????????????????????????????????????????????????????????????????????????????????????????????????????????9 OFDM 信號(hào)的 PAPR 概述 .................................................................................................................9 降低峰均功率比（PAPR）常用的方法 ............................................................................................9 信號(hào)預(yù)畸變技術(shù) .......................................................................................................................10 編碼類(lèi)技術(shù) ...............................................................................................................................10 概率類(lèi)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(duì)比與分析 ..................................................................................14四、OFDM 系統(tǒng)的同步算法設(shè)計(jì) ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????15 OFDM 系統(tǒng)中的同步問(wèn)題及其影響 ...............................................................................................15 OFDM 系統(tǒng)的同步算法概述 ...........................................................................................................15 一種基于 OFDM 循環(huán)前綴同步算法的分析 ..................................................................................16五、OFDM 系統(tǒng)的信道估計(jì) ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????19 信道估計(jì)概述 ...................................................................................................................................19 基于導(dǎo)頻信息的信道估計(jì)算法 ........................................................................................................19 LS 信道估計(jì)算法 ......................................................................................................................20 LMMSE 信道估計(jì)方法 .............................................................................................................20六、OFDM 通信系統(tǒng)設(shè)計(jì) ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????22西南大學(xué)本科畢業(yè)論文IV 發(fā)射機(jī)設(shè)計(jì) .......................................................................................................................................22 信道編碼 ...................................................................................................................................22 QPSK 調(diào)制 ...............................................................................................................................