本文選題：白光LED　切入點(diǎn)：可見光通信　出處：《華中師范大學(xué)》2014年碩士論文

【摘要】：VLC (Visible Light Communication)技術(shù)作為一種新的帶寬無線通信技術(shù),自2000年橫空出世以來,因?yàn)榫哂懈咚僬{(diào)制特性、不占用無線電頻譜資源、安全性高等獨(dú)特優(yōu)勢,受到的關(guān)注度越來越高,已經(jīng)成為國內(nèi)外的主流設(shè)備商、各大學(xué)和科研機(jī)構(gòu)的研究熱點(diǎn),擁有巨大的發(fā)展?jié)摿?在未來的實(shí)用化前景相當(dāng)值得期待。目前對VLC技術(shù)的研究目前主要分為室內(nèi)和室外兩大領(lǐng)域,本文主要對基于白光LED的室內(nèi)可見光通信系統(tǒng)的設(shè)計(jì)與實(shí)現(xiàn)進(jìn)行了研究。 本文首先簡要討論了VLC技術(shù)的研究背景與意義和國內(nèi)外研究現(xiàn)狀,接著對白光LED的光源特性進(jìn)行了研究,是后面LED驅(qū)動電路的設(shè)計(jì)的理論基礎(chǔ),然后重點(diǎn)對室內(nèi)無線信道特性進(jìn)行了分析,具體包括室內(nèi)通信系統(tǒng)的鏈接方式、光路徑、信道沖擊響應(yīng)等,選擇了最簡單的直射視距作為本系統(tǒng)的鏈接方式。通過分析相關(guān)文獻(xiàn),了解到影響系統(tǒng)通信性能的主要因素是多徑效應(yīng)產(chǎn)生的碼間干擾,因此提出引入具有強(qiáng)抗多徑時(shí)延能力的OFDM (Orthogonal Frequency Division Multiplexing)技術(shù),并詳細(xì)介紹了它的基本原理,最后設(shè)計(jì)了一套基于白光LED的室內(nèi)可見光通信試驗(yàn)系統(tǒng),其中,PC機(jī)用來發(fā)送和最終接收數(shù)據(jù),調(diào)制和解調(diào)模塊是基于Quartus Ⅱ11.0開發(fā)環(huán)境通過FPGA (Field Programmable Gate Array)實(shí)現(xiàn)的,與傳統(tǒng)的通過硬件電路實(shí)現(xiàn)相比更簡便快捷,且性能更優(yōu)越。 本文重點(diǎn)是整個系統(tǒng)的設(shè)計(jì)工作,首先,設(shè)計(jì)了LED驅(qū)動電路、前置放大電路和濾波與主放大電路,同時(shí)為了克服調(diào)制信號可能存在的變形,在調(diào)制模塊和驅(qū)動模塊間加入了高速比較器對信號根據(jù)設(shè)定的標(biāo)準(zhǔn)電平進(jìn)行整形處理,得到標(biāo)準(zhǔn)的矩形方波；其次,OFDM系統(tǒng)的設(shè)計(jì),具體包括各個小模塊到最后調(diào)制和解調(diào)兩大模塊的整體實(shí)現(xiàn)：最后,完成整個系統(tǒng)的搭建,通過比較PC機(jī)發(fā)送和接收的數(shù)據(jù)是否相同來判斷系統(tǒng)能否正常工作,該實(shí)驗(yàn)系統(tǒng)的實(shí)現(xiàn)為后續(xù)進(jìn)一步系統(tǒng)的優(yōu)化與實(shí)用化提供了一定的參考和借鑒價(jià)值。
[Abstract]:As a new bandwidth wireless communication technology, VLC visible Light communication technology has attracted more and more attention since its birth in 2000, because of its unique advantages such as high speed modulation, no use of radio spectrum resources, high security and so on.It has become the mainstream equipment at home and abroad, universities and research institutions of research hot spots, has a huge potential for development, in the future practical prospects are worth looking forward to.At present, the research on VLC technology is mainly divided into indoor and outdoor areas. This paper mainly studies the design and implementation of indoor visible light communication system based on white light LED.Firstly, this paper briefly discusses the research background and significance of VLC technology and the current research situation at home and abroad. Then, the characteristics of white light LED are studied, which is the theoretical basis of the design of LED driver circuit.Then the characteristics of indoor wireless channel are analyzed, including the link mode of indoor communication system, optical path, channel impulse response and so on. The most simple direct line-of-sight is chosen as the link mode of the system.By analyzing the related literatures, it is found that the main factor affecting the communication performance of the system is the inter-symbol interference (ISI) caused by the multipath effect. Therefore, the OFDM orthogonal Frequency Division Multiplexing technique with strong anti-multipath delay capability is introduced, and its basic principle is introduced in detail.Finally, a set of indoor visible light communication test system based on white light LED is designed, in which the PC is used to transmit and receive the data, and the modulation and demodulation module is realized by FPGA Field Programmable Gate Arraybased on the development environment of Quartus 鈪，

本文編號：1710282