【摘要】：可見(jiàn)光通信(VLC)是利用LED作為通信信源,光電檢測(cè)器PD作為接收器的一種無(wú)線通信方式。VLC作為未來(lái)潛在的高速無(wú)線通信技術(shù),更高速率成為了通信界不懈的追求。由于光通信采用的強(qiáng)度調(diào)制/直接檢測(cè)方式以及商用LED調(diào)制帶寬較低、電光轉(zhuǎn)換非線性等因素,單個(gè)燈芯的傳輸速率往往受限。針對(duì)以上問(wèn)題,本文對(duì)發(fā)送端為單個(gè)燈具內(nèi)的多個(gè)燈芯、接收端為單一PD構(gòu)成的疊加傳輸系統(tǒng)展開(kāi)分析。主要研究工作如下:1.針對(duì)單一LED速率受限問(wèn)題,提出了采用燈具內(nèi)多個(gè)燈芯并行疊加的傳輸方法,以成倍提升可見(jiàn)光通信的傳輸速率。本文在室內(nèi)視距鏈路LOS下展開(kāi)分析和研究,由于VLC采用的商用LED具有電調(diào)制帶寬有限、電光轉(zhuǎn)換線性區(qū)間較窄等缺點(diǎn),以及受LED和PD物理特性限制所采用的強(qiáng)度調(diào)制/直接檢測(cè)方式制約,使得LED速率受限;正常的照明是由多個(gè)燈芯協(xié)作完成,并且室內(nèi)VLC中信噪比條件較優(yōu)。由此提出了一種多燈芯疊加傳輸方案,該方式下采用K個(gè)燈芯時(shí),系統(tǒng)的傳輸速率可以等效的提升K倍。2.為了檢測(cè)多燈芯會(huì)聚疊加信號(hào),采用疊加編碼調(diào)制(SCM)技術(shù),以驅(qū)動(dòng)電壓差異為檢測(cè)條件,建立了可見(jiàn)光通信疊加編碼調(diào)制(VLC-SCM)模型,給出了聯(lián)合檢測(cè)算法。首先提出了VLC-SCM系統(tǒng)發(fā)送端并行傳輸結(jié)構(gòu);由于LED的瞬時(shí)驅(qū)動(dòng)電壓非負(fù),因此在LED前加上一個(gè)直流偏置,提出了基于開(kāi)關(guān)鍵控OOK調(diào)制的數(shù)據(jù)處理方式;在Lambertian模型基礎(chǔ)上對(duì)多燈芯系統(tǒng)的信道進(jìn)行了研究,得出了疊加傳輸系統(tǒng)并不依賴信道差異性來(lái)區(qū)分?jǐn)?shù)據(jù),為了檢測(cè)疊加后多燈芯會(huì)聚光強(qiáng)信號(hào),在發(fā)送端引入各燈芯驅(qū)動(dòng)電壓差異。最后針對(duì)多燈芯約束、編碼約束,提出了基于OOK的接收端聯(lián)合檢測(cè)算法。仿真驗(yàn)證了VLC-SCM多燈芯疊加傳輸系統(tǒng)較好的高速傳輸性能。3.為了提升疊加傳輸系統(tǒng)的抗非線性性能,采用交織分多址(IDMA)技術(shù),以交織器差異為檢測(cè)條件,建立了可見(jiàn)光通信交織分多址(VLC-IDMA)傳輸模型,給出了串并行兩種檢測(cè)算法和快速性能估計(jì)算法。分析了系統(tǒng)的發(fā)送傳輸結(jié)構(gòu),采用交織器這一唯一差異來(lái)檢測(cè)會(huì)聚光強(qiáng)信號(hào)。提出了采用低碼率編碼時(shí)為全+1的重復(fù)碼結(jié)構(gòu),研究了接收端串行和并行兩種檢測(cè)方式,指出在系統(tǒng)性能和實(shí)現(xiàn)復(fù)雜度上要有所權(quán)衡;接著給出了一種多燈芯疊加傳輸系統(tǒng)性能估計(jì)算法以快速預(yù)測(cè)多燈芯系統(tǒng)的性能。仿真驗(yàn)證了VLC-IDMA多燈芯疊加系統(tǒng)優(yōu)異的高速傳輸性能和抗非線性性能。4.依據(jù)驅(qū)動(dòng)電壓差異、交織器差異和LED的非線性特性,提出了一種聯(lián)合功率分配方案,提升了系統(tǒng)的傳輸效率和檢測(cè)性能。針對(duì)單一驅(qū)動(dòng)電壓差異時(shí)LED容易進(jìn)入非線性區(qū)間,單一交織器差異使得編碼效率較低,提出了多維差異條件下的疊加系統(tǒng)以提升系統(tǒng)性能。由于燈具內(nèi)燈芯數(shù)目適中,采用的無(wú)窮搜索的信噪比演進(jìn)和規(guī)劃的聯(lián)合功率分配符合實(shí)際需求。仿真表明該方案使疊加系統(tǒng)中LED電壓工作在線性范圍內(nèi);與低碼率的多燈芯恒定驅(qū)動(dòng)電壓方案相比,該方案?jìng)鬏斝矢摺?br/>[Abstract]:Visible light communication (VLC) is a wireless communication mode using LED as communication source and photoelectric detector PD as receiver. As a potential high-speed wireless communication technology in the future, VLC has become the unremitting pursuit of the communication field. Because of the intensity modulation/direct detection method used in optical communication and the low modulation bandwidth of commercial LED, electricity is used. The transmission rate of a single wick is often limited due to the non-linearity of light conversion. To solve the above problems, this paper analyzes the superimposed transmission system consisting of multiple wicks in a single luminaire at the transmitter and a single PD at the receiver. Line superposition transmission method is used to multiply the transmission rate of visible light communication. In this paper, the analysis and research are carried out under LOS. The commercial LED used in VLC has the shortcomings of limited bandwidth of electric modulation, narrow linear range of electro-optic conversion, and the intensity modulation/direct detection method limited by the physical characteristics of LED and PD. Constraints restrict the LED speed; normal lighting is accomplished by multiple wicks, and the signal-to-noise ratio of indoor VLC is better. A multi-wick overlay transmission scheme is proposed, in which the transmission rate of the system can be increased by K times when K wicks are used. 2. In order to detect multi-wicks overlay signal, overlay is used. Coded modulation (SCM) technology, taking the difference of driving voltage as the detection condition, establishes the VLC-SCM model and gives the joint detection algorithm. Firstly, the parallel transmission structure of the VLC-SCM system is proposed. Because the instantaneous driving voltage of the LED is non-negative, a DC bias is added to the front of the LED, and the on-off detection algorithm is proposed. Based on Lambertian model, the channel of multi-wick system is studied. It is concluded that the superimposed transmission system does not depend on channel difference to distinguish data. In order to detect the signal of multi-wick convergence intensity after superimposition, the difference of wick driving voltage is introduced at the transmitter. In order to improve the anti-nonlinearity performance of VLC-SCM multi-wick overlay transmission system, interleaved multiple access (IDMA) technology was used to establish the visible light communication interleaving under the detection condition of interleaver difference. The transmission model of VLC-IDMA is presented. Two detection algorithms, serial-parallel and fast performance estimation algorithms, are given. The transmission structure of the system is analyzed. The unique difference between interleavers is used to detect the convergent light intensity signal. A repetitive code structure with low bit rate encoding is proposed. The serial and parallel detection methods at the receiver are studied. Then, a performance estimation algorithm for multi-wick superimposed transmission system is proposed to predict the performance of multi-wick system quickly. Simulation results show that the VLC-IDMA multi-wick superimposed system has excellent high-speed transmission performance and Anti-nonlinear performance. 4. Interleaving according to the difference of driving voltage. A joint power allocation scheme is proposed to improve the transmission efficiency and detection performance of the system, which is based on the difference between the drivers and the non-linear characteristics of the LED. The simulation results show that the proposed scheme makes the LED voltage in the superposition system work within the linear range, and the transmission efficiency of the proposed scheme is higher than that of the low bit rate multi-wick constant driving voltage scheme.
【學(xué)位授予單位】：解放軍信息工程大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TN929.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前8條

1 遲楠;王源泉;王一光;黃星星;陸肖元;;Ultra-high-speed single red green blue light-emitting diode-based visible light communication system utilizing advanced modulation formats[J];Chinese Optics Letters;2014年01期

2 趙顧顥;趙尚弘;蒙文;王翔;朱子行;;多調(diào)制方式下的強(qiáng)度疊加編碼多發(fā)多收大氣光通信系統(tǒng)性能分析[J];光學(xué)學(xué)報(bào);2012年02期

3 胡昊;王紅星;徐建武;孫曉明;劉敏;;無(wú)線光通信中一種迭代解調(diào)的比特交織乘積編碼脈沖位置調(diào)制[J];光學(xué)學(xué)報(bào);2011年08期

4 趙顧顥;趙尚弘;李勇軍;王翔;朱子行;;基于強(qiáng)度疊加編碼的空間光多輸入多輸出通信[J];光學(xué)學(xué)報(bào);2011年07期

5 羅智峰;丘水生;;一種非對(duì)稱IDMA交織器的設(shè)計(jì)及分析[J];華南理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2010年01期

6 雷萌;朱光喜;楊永立;譚力;;IDMA系統(tǒng)中基于SNR演進(jìn)和差分進(jìn)化的功率優(yōu)化研究[J];計(jì)算機(jī)科學(xué);2009年10期

7 王秀妮;馬嘯;白寶明;;多層疊加LDPC碼編碼調(diào)制技術(shù)[J];電子學(xué)報(bào);2009年07期

8 李海濤;林孝康;;碼間干擾信道下疊加碼系統(tǒng)的優(yōu)化設(shè)計(jì)[J];系統(tǒng)工程與電子技術(shù);2009年06期

，

本文編號(hào)：2245733