小波包分復(fù)用論文：基于小波包分復(fù)用技術(shù)的多載波通信系統(tǒng)研究

1、 小波包分復(fù)用論文：基于小波包分復(fù)用技術(shù)的多載波通信系統(tǒng)研究【中文摘要】隨著3G通信技術(shù)日漸成熟并步入商業(yè)化運(yùn)營(yíng),下一代無線通信系統(tǒng)的研制已經(jīng)被提上議事日程。多載波通信與先進(jìn)調(diào)制技術(shù)的結(jié)合,以其較高的頻譜利用率,良好的抗衰落能力,被認(rèn)為是下一代無線通信系統(tǒng)中的核心技術(shù)。小波包分復(fù)用技術(shù)不僅具有良好的抗碼間干擾、載波間干擾的能力,且相比OFDM技術(shù)具備更佳的信道適應(yīng)能力,成為近一段時(shí)間研究的熱點(diǎn)。然而,峰均功率比較高、子載波基的選擇以及最優(yōu)基選取方法較復(fù)雜等難題一直制約著小波包分復(fù)用技術(shù)的進(jìn)一步發(fā)展與應(yīng)用。本文則針對(duì)上述問題,進(jìn)行了深入而細(xì)致的研究。全文首先概括并闡述了多載波調(diào)制與小波包分復(fù)用技

2、術(shù)的研究現(xiàn)狀及發(fā)展前景,介紹了時(shí)頻分析與小波包理論,并以此為基礎(chǔ),分析了在多徑衰落信道模型下,子載波基的選取對(duì)系統(tǒng)抗干擾性能的影響。給出了頻率彌散信道中子載波基的選取原則,提出以小波包函數(shù)替代傳統(tǒng)OFDM技術(shù)中所采用的正弦基作為子載波基進(jìn)行傳輸,利用小波包函數(shù)良好的自正交性與互正交性,來獲取更優(yōu)的抗噪聲與抗干擾性能。實(shí)驗(yàn)結(jié)果驗(yàn)證了本方法的可行性與有效性。接著分析了小波包基的構(gòu)成原則與選擇方法,針對(duì)多載波通信系統(tǒng)的性能要求,選取ICI與ISI聯(lián)合功率及峰均功率比作為度量準(zhǔn)則,并將子載波數(shù)目作為搜索約束條件,提出了一種基于根節(jié)點(diǎn)逐級(jí)向下按二進(jìn)支路分解,利用度量準(zhǔn)則函數(shù)決定父子節(jié)點(diǎn)間取舍的最優(yōu)基搜索

3、算法,并解決了約束條件下的最優(yōu)基輸出問題。最后在4徑Rayleigh衰落信道模型下的仿真結(jié)果表明:該算法的運(yùn)算速度優(yōu)于現(xiàn)有的兩種算法,且采用最優(yōu)基結(jié)構(gòu)的系統(tǒng)比全分解結(jié)構(gòu)的系統(tǒng)性能提升約20%。最后,總結(jié)了全文的主要工作,指出了本文研究的局限性與不足之處,展望了小波包分復(fù)用技術(shù)及多載波通信技術(shù)的未來發(fā)展趨勢(shì)。【英文摘要】With the maturity of 3G communication technology and already into commercial operation, the development of next generation wireless communic

4、ation systems have been put on the agenda. Advanced modulation combined with multi-carrier communication, with its high spectral efficiency, good anti-fading ability, is considered as the key technology in next-generation wireless communication system. Wavelet packet division multiplexing does not o

5、nly have good anti-ISI, ICI ability, but also has better ability of adapting to the channel than OFDM technology. However, difficulties in high peak to average power ratio, sub-carrier bases selection and optimal basis selection has restricted the further development and application of wavelet packe

6、t division multiplexing. This thesis will address the above issues, and process deep and meticulous research.This thesis first summarized and described the current statue and future prospects of multi-carrier modulation and wavelet packet division multiplexing, introduces the time-frequency analysis

7、 and wavelet packet theory. Based on that, this thesis analysed the anti-interference performance. of different sub-carrier bases in multi-path fading channel, and given the selection principle of sub-carrier bases in frequency dispersion channel, wavelet packet function is proposed to replace the t

8、raditional sine-base used in OFDM technology for transmission, using its self and cross orthogonality to obtain better performance against noise and interference. Experimental results demonstrate the feasibility and effectiveness of this method.In the following part, analyzed the composition and sel

9、ection principle of wavelet packet basis, and a novel search algorithm for wavelet packet basis was proposed. This algorithm decomposes the whole wavelet packet library from top to bottom by its binary branch, use ICI and ISI integrated power and Peak to Average Power Ratio (PAPR) for competitive de

10、cision to select optimal basis. Finally the algorithm was tested in 4-path Rayleigh fading channel. Simulation results indicated that: the operation speed of the algorithm is better than two existing algorithms, and the output of the optimal basis structure gain about 20% performance increase than f

11、ull decomposed structure.Final chapter is the summary of the main work and future trend of the wavelet packet division multiplexing and multi-carrier communication technology.【關(guān)鍵詞】小波包分復(fù)用 多載波通信 子載波基 最優(yōu)基 峰均功率比 正交頻分復(fù)用【英文關(guān)鍵詞】Wavelet packet division multiplexing Multi-carrier communication Sub-carrier ba

12、sis Optimal basis peak to Average power ratio Orthogonal frequency division multiplexing【目錄】基于小波包分復(fù)用技術(shù)的多載波通信系統(tǒng)研究 摘要 4-5 ABSTRACT 5 第一章 緒論 8-14 1.1 引言 8-9 1.2 研究背景及現(xiàn)狀 9-12 1.2.1 多載波調(diào)制技術(shù) 9-11 1.2.2 小波包分復(fù)用技術(shù) 11-12 1.3 本文的主要內(nèi)容及結(jié)構(gòu) 12-14 第二章 多載波調(diào)制系統(tǒng) 14-20 2.1 單載波調(diào)制 14 2.2 多載波調(diào)制 14-16 2.2.1 多載波調(diào)制的原理 14-15

13、2.2.2 多載波調(diào)制系統(tǒng)的優(yōu)缺點(diǎn) 15-16 2.3 多載波調(diào)制系統(tǒng)的實(shí)現(xiàn) 16-19 2.3.1 MC-CDMA 系統(tǒng) 16-17 2.3.2 OFDM 系統(tǒng) 17-18 2.3.3 WPDM 系統(tǒng) 18-19 2.4 本章小結(jié) 19-20 第三章 小波理論與小波包分復(fù)用 20-30 3.1 時(shí)頻分析與小波理論 20-25 3.1.1 Fourier 變換 20-21 3.1.2 Gabor 變換 21 3.1.3 小波變換 21-24 3.1.4 小波包變換 24-25 3.2 小波包分復(fù)用系統(tǒng) 25-29 3.2.1 小波包分復(fù)用系統(tǒng)的原理與結(jié)構(gòu) 25-28 3.2.2 WDPM 的特

14、點(diǎn)與優(yōu)勢(shì) 28-29 3.3 本章小結(jié) 29-30 第四章 多載波通信系統(tǒng)中子載波基的選取 30-40 4.1 引言 30-31 4.2 無線通信信道 31-34 4.2.1 無線傳播環(huán)境的多樣性與多徑性 31-32 4.2.2 無線信道中的衰落類型 32-33 4.2.3 無線信道模型 33-34 4.3 子載波基的優(yōu)化選取 34-37 4.3.1 問題的提出 34-35 4.3.2 信道干擾的理論分析 35-36 4.3.3 子載波基的優(yōu)化選取 36-37 4.4 仿真分析與結(jié)論 37-38 4.5 本章小結(jié) 38-40 第五章 小波包分復(fù)用系統(tǒng)中的最優(yōu)小波包基選擇 40-51 5.1 引言 40-41 5.2 最優(yōu)小波包基的定義 41-42 5.3 現(xiàn)有的最優(yōu)基選取方法 42-45 5.3.1 最優(yōu)基搜索算法 42-43 5.3.2 窮舉算法 43-45 5.4