【正文】 題 目 OFDM 的基本原理與關(guān)鍵技術(shù)研究 學(xué)生姓名 陳 悠 學(xué)號(hào) 1113024080 所在學(xué)院 物 理 與 電 信 工 程 學(xué) 院 專業(yè)班級(jí) 通 信 工 程 專 業(yè) 1103 班 指導(dǎo)教師 王 桂 寶 完成地點(diǎn) 物 理 與 電 信 工 程 學(xué) 院 實(shí) 驗(yàn) 室 2020 年 5 月 31 日 OFDM 的基本原理和關(guān)鍵技術(shù)研究 陳悠 （ 陜西理工學(xué)院物理與電信工程學(xué)院通信 1103班，陜西 漢中 723003） 指導(dǎo)教師：王桂寶 [摘 要 ] OFDM(Orthogonal Frequency Division Multiplexing)是未來(lái)移動(dòng)通信中具有應(yīng)用前景和競(jìng)爭(zhēng)力的一項(xiàng)技術(shù)。該技術(shù)具有頻譜利用率高、抗衰落能力強(qiáng)、調(diào)制和解調(diào)容易實(shí)現(xiàn)等優(yōu)點(diǎn)。但是對(duì)時(shí)頻偏差非常敏感，特別是載波頻率偏差。當(dāng)存在頻率偏差時(shí)，子載波之間的正交性遭到破壞，從而引起嚴(yán)重的載波間干擾。在 OFDM 系統(tǒng)中，進(jìn)行精確的時(shí)頻偏差估計(jì)非常重要。因此，本論 文圍繞 OFDM 系統(tǒng)中的同步問(wèn)題開(kāi)展研究。本文所做的工作主要有： 首先，介紹了 OFDM 系統(tǒng)原理，對(duì)系統(tǒng)存在的關(guān)鍵技術(shù)進(jìn)行了探討，建立了 OFDM 仿真系統(tǒng)。并對(duì)系統(tǒng)存在的優(yōu)缺點(diǎn)進(jìn)行了分析和歸納。 其次，研究了 OFDM 系統(tǒng)中的同步原理，并分析了系統(tǒng)中存在的載波同步偏差、樣值同步偏差、符號(hào)定時(shí)同步偏差對(duì)系統(tǒng)性能造成的影響。 第三，對(duì)基于循環(huán)前綴的同步算法進(jìn)行了理論分析和仿真實(shí)現(xiàn)，提出了一種充分利用循環(huán)前綴和相對(duì)應(yīng)部分相關(guān)性的改進(jìn)算法，這是以后研究的重點(diǎn) 最后，對(duì)本畢業(yè)設(shè)計(jì)做出了總結(jié)和展望 [關(guān)鍵詞 ]正 交頻分復(fù)用（ OFDM)。同步 。符號(hào)定時(shí)偏移估計(jì)；頻率偏移估計(jì) Research on basic principle and key technology of OFDM ChenYou (Grade 11,Class 3,Major of Communication Engineering， School of Physics and telemunication Engineering of Shaanxi University of Technology, Hanzhong 723003,China) Tutor: Wang Guibao Abstract: Orthogonal Frequency Division Multiple (OFDM) is an effective and promising technique in future mobile munications. It has efficient bandwidth utilization and the robustness against Multipath delay, and else it is easier to implement the modulation and demodulation. But OFDM is very sensitive to symbol timing offset and carrier frequency offset. When there is a carrier frequency synchronization error in OFDM systems, the orthogonality between subcarriers can39。t be maintained, serious intercarrier interference is introduced. Therefore precise timing and frequency offset estimation is very important for OFDM systems. So we study the synchronization of the OFDM systems in the thesis. Main works in the thesis: Firstly, the principle and the primary technology of OFDM systems is introduced in the article, in addition it introduces the advantages and disadvantages of the OFDM systems. Secondly, we study the synchronization principle and analyze the performance influence in OFDM systems which have the errors of timing synchronization、 frequency synchronization and the sampling rate synchronization. Thirdly, the synchronization algorithm based on cyclic prefix of theory analysis and simulation implementation, put forward a kind of make full use of the cyclic prefix and the corresponding part of the correlation of the improved algorithm, which is the focus of future research. Finally, the graduation design made a summary and outlook Keywords: orthogonal frequency division multiplexing； synchronization； symbol timing offset estimation；frequency offset 目錄 緒論 ........................................................................................................................ 1 研究背景 .......................................................................................................... 1 國(guó)內(nèi)外研究現(xiàn)狀 ............................................................................................... 2 本文的主要工作及內(nèi)容安排 .............................................................................. 3 OFDM 系統(tǒng)原理及關(guān)鍵技術(shù) ....................................................................................... 4 OFDM 系統(tǒng)原理 ................................................................................................... 4 OFDM 系統(tǒng)的基本模型 .............................................................................. 4 OFDM 系統(tǒng)的調(diào)制和解調(diào)原理 ................................................................... 4 保護(hù)間隔和循環(huán)前綴 .............................................................................. 6 建立 OFDM系統(tǒng)仿真模型 .......................................................................... 7 OFDM 技術(shù)的優(yōu)缺點(diǎn) .......................................................................................... 10 OFDM 系統(tǒng)的關(guān)鍵技術(shù) ...................................................................................... 10 本章小結(jié) .......................................................................................................... 12 OFDM 系統(tǒng)的同步技術(shù)分析 ...................................................................................... 12 OFDM 系統(tǒng)中的同步原理 ................................................................................... 12 同步偏差對(duì) OFDM 系統(tǒng)性能的影響 ................................................................. 17 載波同步偏差分析 ............................................................................... 17 OFDM 系統(tǒng)的同步算法 ...................................................................................... 18 本章小結(jié) ........................................................................................................ 19 基于循環(huán)前綴的同步算法 ...................................................................................... 19 OFDM聯(lián)合同步算法 .................................................................. 19 ML 估計(jì)原理 ........................................................................................... 20 ML 算法仿真估計(jì) .................................................................................... 21 本章小結(jié) ........................................................................................................ 24 總結(jié)與展望 ........................................................................................................... 24 全文總結(jié) ........................................................................................................ 24 ............................................................................................ 25 致謝 .................................................................