本文選題：歐洲第二代地面數(shù)字電視廣播 + 代數(shù)構(gòu)造�。� 參考：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：本文以O(shè)FDM系統(tǒng)中普遍采用的二維星座旋轉(zhuǎn)技術(shù)為研究基礎(chǔ),以DVB-T2系統(tǒng)為例首先介紹了數(shù)字電視概念、優(yōu)勢和廣播方式等概況,研究了國內(nèi)外地面數(shù)字電視廣播技術(shù)的發(fā)展情況,同時(shí)列舉了各大主流數(shù)字電視廣播傳輸標(biāo)準(zhǔn),繼而介紹了本文研究出發(fā)點(diǎn)DVB-T2系統(tǒng)的提出背景、系統(tǒng)組織結(jié)構(gòu)和星座旋轉(zhuǎn)技術(shù)在該系統(tǒng)中的應(yīng)用。然后簡單研究了國內(nèi)外現(xiàn)有的實(shí)現(xiàn)高維星座旋轉(zhuǎn)技術(shù)：代數(shù)數(shù)論構(gòu)造旋轉(zhuǎn)矩陣的方法和通過兩次旋轉(zhuǎn)實(shí)現(xiàn)四維星座旋轉(zhuǎn)的方法。代數(shù)數(shù)論構(gòu)造旋轉(zhuǎn)矩陣的方法實(shí)現(xiàn)比較復(fù)雜,使用時(shí)需要根據(jù)不同條件找出對(duì)應(yīng)的最小多項(xiàng)式以及滿足系統(tǒng)條件的映射函數(shù),而且現(xiàn)在沒有對(duì)應(yīng)復(fù)雜度比較低的解映射方法,但是構(gòu)造過程中提到的很多理論對(duì)于新方法的設(shè)計(jì)和分析有很大幫助。該方法從最小化信噪比上界出發(fā)的思路也是后續(xù)設(shè)計(jì)高維星座方法的重要出發(fā)點(diǎn),通過該方法可以實(shí)現(xiàn)不同維度的星座旋轉(zhuǎn)。原有的通過兩次二維星座旋轉(zhuǎn)達(dá)到四階分集增益的方法實(shí)現(xiàn)的步驟比較簡單,復(fù)雜度也比較低,但是設(shè)計(jì)的信號(hào)重組方式不適合復(fù)雜信道情況。本文在對(duì)上述幾種方法進(jìn)行推導(dǎo)和分析的基礎(chǔ)上提出了新的實(shí)現(xiàn)四維星座旋轉(zhuǎn)的方法,雖然新方法還是從旋轉(zhuǎn)角度出發(fā)基于兩次二維星座旋轉(zhuǎn)來實(shí)現(xiàn)四階分集增益,但是拋開了原來的信號(hào)重組方法,針對(duì)復(fù)雜信道環(huán)境設(shè)計(jì)了新的信號(hào)組合方式,本文最后針對(duì)新四維星座旋轉(zhuǎn)算法的旋轉(zhuǎn)矩陣分析提出了一種改進(jìn)的最大似然檢測算法,使用改進(jìn)檢測算法后系統(tǒng)性能并沒有損失同時(shí)和原來的四維星座旋轉(zhuǎn)方法相比復(fù)雜度也沒有增加。同時(shí)該設(shè)計(jì)方法應(yīng)用在系統(tǒng)里不需要使實(shí)虛部經(jīng)歷不同的信道衰落,這樣可以避免Q路循環(huán)延時(shí)技術(shù)帶來的一些弊端,有助于系統(tǒng)性能的提升。本文第四章以QPSK調(diào)制方式為例重點(diǎn)介紹了該方法的步驟和仿真結(jié)果。并且對(duì)旋轉(zhuǎn)矩陣進(jìn)行分析比較了不同方法實(shí)現(xiàn)最大分集階數(shù)的條件。
[Abstract]:Based on the two-dimensional constellation rotation technology commonly used in OFDM system, this paper firstly introduces the concept, advantages and broadcasting methods of digital television, and studies the development of terrestrial digital television broadcasting technology at home and abroad.At the same time, this paper enumerates the main digital television broadcasting transmission standards, and then introduces the background of the research starting point DVB-T2 system, the system organization structure and the application of constellation rotation technology in this system.Then, the existing techniques to realize the rotation of high-dimensional constellations at home and abroad are briefly studied: the method of constructing rotation matrix by algebraic number theory and the method of realizing rotation of four-dimensional constellations by twice-rotation.The method of constructing rotation matrix based on algebraic number theory is very complicated. It is necessary to find out the corresponding minimum polynomial and the mapping function satisfying the system condition according to different conditions, and there is no solution mapping method with lower corresponding complexity.However, many of the theories mentioned in the construction process are of great help to the design and analysis of new methods.The idea of minimizing the upper bound of signal-to-noise ratio (SNR) is also an important starting point for the subsequent design of high-dimensional constellations, by which the rotation of constellations of different dimensions can be realized.The original method to achieve the fourth order diversity gain by two two dimensional constellation rotation is simple and low complexity, but the signal recombination method is not suitable for complex channel.Based on the derivation and analysis of the above methods, a new method to realize the rotation of four dimensional constellations is proposed in this paper, although the new method is based on the rotation of two two dimensional constellations to realize the fourth order diversity gain.But the original signal recombination method is put aside, and a new signal combination method is designed for complex channel environment. In the end, an improved maximum likelihood detection algorithm is proposed for the rotation matrix analysis of the new four-dimensional constellation rotation algorithm.After using the improved detection algorithm, the system performance is not lost and the complexity is not increased compared with the original four-dimensional constellation rotation method.At the same time, it is not necessary to make the real virtual part go through different channel fading in the system, which can avoid some disadvantages brought by the Q-path cyclic delay technology and help to improve the performance of the system.In chapter 4, the QPSK modulation method is taken as an example to introduce the steps of the method and the simulation results.The conditions of realizing the maximum diversity order by different methods are analyzed and compared.
【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN929.53

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 石康;王萍;;基于DVB-T2的旋轉(zhuǎn)星座解映射算法及其改進(jìn)[J];電視技術(shù);2014年07期

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本文編號(hào)：1755823