本文關(guān)鍵詞： 正交頻分復(fù)用 峰均功率比 部分傳輸序列法 輸入序列定標(biāo)法　出處：《天津大學(xué)》2009年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】： 正交頻分復(fù)用(OFDM)是一種特殊的多載波傳輸技術(shù)。它的基本思想是將所要傳輸?shù)母咚贁?shù)據(jù)流通過(guò)串/并轉(zhuǎn)換,變成多路并行的若干個(gè)子數(shù)據(jù)流,每個(gè)子數(shù)據(jù)流具有比發(fā)送端原始數(shù)據(jù)流低得多的傳輸速率,然后用這些子數(shù)據(jù)流去并行調(diào)制若干個(gè)相互正交的載波,最后再合并成一個(gè)OFDM符號(hào)進(jìn)行傳輸。 OFDM技術(shù)的優(yōu)點(diǎn)在于它可以提供更高的頻譜效率、更強(qiáng)的抗符號(hào)間干擾能力和更好的抗多徑衰落能力。但是,OFDM技術(shù)也有一些缺點(diǎn),例如對(duì)頻偏的敏感性、較高的峰均功率比等,這些問(wèn)題限制了OFDM技術(shù)的發(fā)展和應(yīng)用。 本文論述了移動(dòng)通信的發(fā)展概況,OFDM系統(tǒng)的基本原理、發(fā)展概況、主要技術(shù)及優(yōu)缺點(diǎn),重點(diǎn)論述了OFDM系統(tǒng)中降低PAPR的方法。目前,國(guó)內(nèi)外降低PAPR技術(shù)的方法主要包括信號(hào)畸變類(lèi)方法、編碼類(lèi)方法和概率類(lèi)方法。其中:信號(hào)畸變類(lèi)方法直接在OFDM信號(hào)幅度峰值或其附近進(jìn)行非線(xiàn)性操作來(lái)降低信號(hào)的PAPR值;編碼類(lèi)方法是通過(guò)限制可用于傳輸?shù)男盘?hào)碼集來(lái)降低PAPR,其核心思想是運(yùn)用一種特殊的前向糾錯(cuò)編碼技術(shù)來(lái)剔除高PAPR的OFDM信號(hào);概率類(lèi)方法著眼于降低OFDM信號(hào)峰值出現(xiàn)的概率。 針對(duì)PTS全搜索算法計(jì)算復(fù)雜度過(guò)大,而傳統(tǒng)的PTS迭代算法性能較差的缺點(diǎn),本文提出了一種PTS改進(jìn)算法,仿真結(jié)果表明,該算法很好地折衷了OFDM系統(tǒng)的PAPR性能和計(jì)算的復(fù)雜度。 針對(duì)傳統(tǒng)的輸入序列定標(biāo)全搜索算法計(jì)算復(fù)雜度過(guò)大的缺點(diǎn),本文提出了一種簡(jiǎn)化算法,該算法是通過(guò)施加終止門(mén)限并進(jìn)行迭代計(jì)算實(shí)現(xiàn)的,仿真結(jié)果驗(yàn)證了該算法的有效性。
[Abstract]:Orthogonal Frequency Division Multiplexing (OFDM) is a special multicarrier transmission technology. The basic idea of OFDM is to transform the high speed data stream to several sub-data streams in parallel. Each sub-data stream has a transmission rate much lower than the original data stream at the sender, and these sub-data streams are then used to modulate a number of mutually orthogonal carriers in parallel. Finally, it is merged into a OFDM symbol for transmission. The advantage of OFDM technology is that it can provide higher spectral efficiency, stronger anti-intersymbol interference ability and better anti-multipath fading ability, but OFDM technology also has some disadvantages. For example, the sensitivity to frequency offset and the high peak-to-average power ratio limit the development and application of OFDM technology. This paper discusses the basic principle, development, main technology, advantages and disadvantages of the mobile communication system, especially the methods to reduce the PAPR in the OFDM system. The methods of reducing PAPR technology at home and abroad mainly include signal distortion class method. Coding method and probabilistic method, in which the signal distortion class method directly performs nonlinear operation at or near the peak amplitude of the OFDM signal to reduce the PAPR value of the signal; The coding method is to reduce the PAPR by limiting the number set which can be transmitted. Its core idea is to use a special forward error correction coding technology to eliminate the high PAPR OFDM signal. Probabilistic methods aim at reducing the probability of peak OFDM signal. Because the computational complexity of PTS full search algorithm is too large, but the performance of traditional PTS iterative algorithm is poor, an improved PTS algorithm is proposed in this paper, and the simulation results show that. This algorithm tradeoffs the PAPR performance and computational complexity of OFDM system. Aiming at the disadvantage of the traditional full-search algorithm of input sequence calibration, a simplified algorithm is proposed in this paper, which is realized by applying the termination threshold and iterating calculation. Simulation results verify the effectiveness of the algorithm.
【學(xué)位授予單位】：天津大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2009
【分類(lèi)號(hào)】：TN919.3

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 張藝朦;OFDM水聲通信多普勒估計(jì)技術(shù)研究[D];哈爾濱工程大學(xué);2012年

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本文編號(hào)：1449855