發(fā)布時間：2018-05-04 23:00

  本文選題：信道估計(jì) + 壓縮感知　； 參考：《西安電子科技大學(xué)》2014年碩士論文

【摘要】：信道估計(jì)技術(shù)是獲取信道狀態(tài)信息的核心技術(shù)之一,依據(jù)一定的估計(jì)準(zhǔn)則實(shí)現(xiàn)系統(tǒng)信道對輸入信號傳輸過程產(chǎn)生的影響,進(jìn)一步達(dá)到提高系統(tǒng)性能的目的。而壓縮感知理論(CS,Compressed Sensing)最大的優(yōu)勢是以低速率采樣(遠(yuǎn)小于奈奎斯特速率)實(shí)現(xiàn)信號重構(gòu),而信號重構(gòu)又是信道估計(jì)過程中的關(guān)鍵步驟。應(yīng)用CS理論需要滿足信道和信號稀疏特性,本文在驗(yàn)證超寬帶(UWB,Ultra-WideBand)系統(tǒng)信道滿足該性質(zhì)的基礎(chǔ)上,利用CS實(shí)現(xiàn)該信道的估計(jì)過程,從而實(shí)現(xiàn)性能優(yōu)良的信道系統(tǒng)。首先,本文全面介紹壓縮感知理論,并闡明其作為信道估計(jì)的理論支持,同時分析了超寬帶系統(tǒng)的框架及其特點(diǎn),并驗(yàn)證該系統(tǒng)對于壓縮感知理論的適應(yīng)性,接著在超寬帶系統(tǒng)信道模型基礎(chǔ)上具體描述了該信道上的信號傳輸和信號估計(jì)過程。其次,給出了一個基于CS的UWB系統(tǒng)信道估計(jì)方案。針對傳統(tǒng)基于導(dǎo)頻的信道估計(jì)方案的不足,本文基于壓縮感知估計(jì)算法提出一個應(yīng)用于超寬帶系統(tǒng)的信道估計(jì)方案,仿真結(jié)果顯示,后者可以實(shí)現(xiàn)更好的系統(tǒng)性能且不必付出更多的觀測數(shù)據(jù),從而也驗(yàn)證了以低于奈奎斯特采樣的速率可以實(shí)現(xiàn)信號的恢復(fù),仿真還分析了會影響CS恢復(fù)算法性能的因素。最后,給出基于SN-CS的UWB系統(tǒng)信道估計(jì)方案。針對感知算法中觀測矩陣的構(gòu)造和獲取,本文在研究現(xiàn)有高斯隨機(jī)矩陣和伯努利矩陣作為感知矩陣的基礎(chǔ)上提出了一個新的SN-CS(Compressed Sensing Based on Sub-Nyquist)算法。新算法利用基于亞奈奎斯特的寬帶調(diào)制器架構(gòu)實(shí)現(xiàn)模數(shù)轉(zhuǎn)換的低速抽樣過程,實(shí)現(xiàn)了通過硬件方式直接獲取相應(yīng)的快速傅里葉變換系數(shù)來構(gòu)造感知矩陣,更能貼近信道特性。同時,本文將新算法應(yīng)用于超寬帶系統(tǒng)并提出四種實(shí)際的采樣結(jié)構(gòu)的框架然后予以仿真實(shí)現(xiàn),并就能量獲取和均方根誤差兩個參數(shù)對比本方案和奈奎斯特采樣恢復(fù)的性能,結(jié)果表明本方案中設(shè)計(jì)結(jié)構(gòu)的實(shí)現(xiàn)能夠?qū)崿F(xiàn)幾乎和奈奎斯特一樣的恢復(fù)性能,而且只需要遠(yuǎn)少于奈奎斯特采樣所需要的采樣點(diǎn)。
[Abstract]:Channel estimation is one of the key technologies to obtain channel state information, and the influence of the system channel on the input signal transmission process is realized according to certain estimation criteria, and the purpose of improving the system performance is to be further improved. The most important advantage of CS (Compressed Sensing) is to sample at a low rate (far less than Naquis) The signal reconstruction is the key step in the channel estimation. The application of CS theory needs to meet the sparse characteristics of the channel and signal. In this paper, the channel estimation process is realized by using CS to realize the channel estimation on the basis of the authentication of the UWB (Ultra-WideBand) system, so as to realize the channel with excellent performance. Firstly, this paper introduces the theory of compressed sensing, expounds its theoretical support as channel estimation, analyzes the framework and characteristics of UWB system, and verifies the adaptability of the system to the compression perception theory, and then describes the signal transmission and signal on the channel based on the UWB system channel model. Secondly, a channel estimation scheme for UWB system based on CS is given. In view of the shortage of traditional channel estimation based on pilot, this paper proposes a channel estimation scheme applied to UWB based on compressed sensing estimation algorithm. The simulation results show that the latter can achieve better system performance and do not have to pay. More observation data, which also validates the recovery of the signal at a rate below the Nyquist sampling rate. The simulation also analyzes the factors that affect the performance of the CS recovery algorithm. Finally, the SN-CS based channel estimation scheme for the UWB system is given. In view of the construction and acquisition of the observation matrix in the perceptual algorithm, this paper studies the existing Gauss follow. A new SN-CS (Compressed Sensing Based on Sub-Nyquist) algorithm is proposed on the basis of the mechanical matrix and the Bernoulli matrix as the perceptual matrix. The new algorithm uses a broadband modulator architecture based on the sub Nyquist to realize the low speed sampling process of the analog digital conversion, and achieves the corresponding fast Fourier transform directly through the hard piece mode. In this paper, the new algorithm is applied to the UWB system and the framework of four actual sampling structures is proposed and simulated. The performance of the scheme and the Nyquist sampling recovery is compared with the two parameters of energy acquisition and root mean square error. The results show that the scheme is in this scheme. The implementation of the design structure can achieve almost the same recovery performance as Nyquist, and much less than the sampling points needed by Nyquist sampling.

【學(xué)位授予單位】：西安電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TN925;TN911.23

【參考文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 朱曉明;超寬帶通信系統(tǒng)中信道估計(jì)方法的研究[D];哈爾濱工程大學(xué);2008年

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本文編號：1845043