本文選題：高速移動　切入點(diǎn)：MIMO-OFDM　出處：《杭州電子科技大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：正交頻分復(fù)用(Orthogonal Frequency Division Multiplexing，OFDM)技術(shù)具有抗多徑干擾能力強(qiáng)、頻譜利用率高、數(shù)據(jù)傳輸速率快和實(shí)現(xiàn)比較簡單等優(yōu)點(diǎn)，因而在無線通信領(lǐng)域引起了廣泛的關(guān)注，并成為3G/4G標(biāo)準(zhǔn)的核心技術(shù)之一。多輸入多輸出(Multiple Input MultipleOutput，MIMO)技術(shù)在不增加系統(tǒng)帶寬和天線總發(fā)射功率的前提下成倍的提高無線通信系統(tǒng)的容量和頻譜效率。MIMO-OFDM技術(shù)融合了MIMO和OFDM技術(shù)的優(yōu)點(diǎn)，，并被標(biāo)準(zhǔn)化組織確認(rèn)為第四代移動通信系統(tǒng)的關(guān)鍵技術(shù)。隨著高速鐵路的快速發(fā)展，移動通信用戶對高速移動環(huán)境下高速數(shù)據(jù)業(yè)務(wù)的需求日益增加，因此對高速移動環(huán)境下的OFDM和MIMO-OFDM系統(tǒng)的研究成為當(dāng)務(wù)之急。 本文針對高速移動環(huán)境下的OFDM和MIMO-OFDM系統(tǒng)的信道估計(jì)算法進(jìn)行了深入研究。 首先，本文分析了高鐵環(huán)境下無線信道的特性，并詳細(xì)分析了一種適合高鐵環(huán)境的新萊斯衰落信道仿真模型；其次，針對高速移動OFDM系統(tǒng)中的子載波間干擾(Inter carrierinterference，ICI)進(jìn)行了詳細(xì)的分析,并在新萊斯衰落仿真信道模型下對各種常見的信道估計(jì)算法和插值算法分別進(jìn)行了仿真對比與分析；再次，為了提高速移動OFDM系統(tǒng)的信道估計(jì)的精度，本文提出了一種基擴(kuò)展模型(Base expansion model，BEM)聯(lián)合反饋分組離散傅里葉變換(Discrete Fourier Transform，DFT)的信道估計(jì)算法，該算法通過BEM信道估計(jì)得到載波間干擾(Inter-Carrier Interference，ICI)系數(shù)項(xiàng)，并消除ICI得到反饋信息，再由分組DFT信道估計(jì)算法二次消除ICI和其他干擾項(xiàng)，仿真結(jié)果證實(shí)該算法可以有效的提高系統(tǒng)整體的性能；最后，為了提高高速移動MIMO-OFDM系統(tǒng)信道估計(jì)的性能，本文在傳統(tǒng)的最優(yōu)MIMO-OFDM系統(tǒng)導(dǎo)頻序列基礎(chǔ)上，提出了一種適用于高速移動MIMO-OFDM信道估計(jì)的導(dǎo)頻序列，在插入該導(dǎo)頻序列后MIMO-OFDM系統(tǒng)每一對收-發(fā)天線對可以看成是獨(dú)立的SISO-OFDM系統(tǒng)，此時可以采用BEM信道估計(jì)算法得到每一對收-發(fā)天線之間的信道響應(yīng)，再由MIMO檢測模塊獲得各天線的輸入信號估計(jì)值，并估計(jì)得到每對收-發(fā)天線上的ICI系數(shù)項(xiàng)，進(jìn)而計(jì)算出反饋信號，最后利用分組DFT信道估計(jì)算法二次消除ICI和其他干擾項(xiàng)，仿真證實(shí)基擴(kuò)展模型聯(lián)合反饋分組離散傅里葉變換的信道估計(jì)算法適用于高速移動的MIMO-OFDM系統(tǒng)。
[Abstract]:Orthogonal Frequency Division Multiplexing OFDM (OFDM) technology has attracted wide attention in the field of wireless communication because of its strong ability to resist multipath interference, high spectral efficiency, fast data transmission rate and simple implementation. It has become one of the core technologies of 3G / 4G standard. Multi-Input-Multiple Input multiple output Mimo (MIMO-OFDM) technology has been integrated to improve the capacity and spectral efficiency of wireless communication system without increasing system bandwidth and antenna total transmit power. The advantages of MIMO and OFDM technology, With the rapid development of high-speed railway, the demand of mobile communication users for high-speed data services in high-speed mobile environment is increasing. Therefore, the research of OFDM and MIMO-OFDM systems in high speed mobile environment becomes urgent. In this paper, channel estimation algorithms for OFDM and MIMO-OFDM systems in high speed mobile environment are studied. Firstly, the characteristics of wireless channel in high-speed railway environment are analyzed, and a simulation model of Neo-Rice fading channel suitable for high-speed railway environment is analyzed in detail. In this paper, the inter carrier interference (ICI) in high speed mobile OFDM system is analyzed in detail, and a variety of common channel estimation algorithms and interpolation algorithms are compared and analyzed respectively under the simulation channel model of New Rice fading. Thirdly, In order to improve the accuracy of channel estimation for fast moving OFDM systems, this paper presents a channel estimation algorithm based on Base expansion Model (BEM) and discrete Fourier transform (DFT) combined feedback packet discrete Fourier transform (DFT). In this algorithm, the inter-carrier interference coefficient term is obtained by BEM channel estimation, and the feedback information is eliminated by ICI. Then the ICI and other interference items are eliminated twice by the packet DFT channel estimation algorithm. Simulation results show that the proposed algorithm can effectively improve the overall performance of the system. Finally, in order to improve the performance of channel estimation for high-speed mobile MIMO-OFDM systems, this paper is based on the traditional optimal pilot sequence of MIMO-OFDM systems. A pilot sequence suitable for high-speed mobile MIMO-OFDM channel estimation is proposed. After inserting the pilot sequence, each pair of transceiver antenna pairs in the MIMO-OFDM system can be regarded as an independent SISO-OFDM system. At this time, the channel response between each pair of transceiver antennas can be obtained by using BEM channel estimation algorithm, and then the input signal estimation value of each antenna can be obtained by the MIMO detection module, and the ICI coefficient term on each pair of transceiver antennas can be estimated. Then the feedback signal is calculated. Finally, the ICI and other interference items are eliminated twice by using the packet DFT channel estimation algorithm. The simulation results show that the channel estimation algorithm based on the basis extension model combined with the feedback packet discrete Fourier transform is suitable for the high-speed moving MIMO-OFDM system.
【學(xué)位授予單位】：杭州電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN919.3

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本文編號：1563652