發(fā)布時間：2018-09-17 07:46

【摘要】：無線光通信(Optical Wireless Communication,OWC)技術(shù)因其調(diào)制帶寬大,傳輸速率高,保密性好以及無需授權(quán)頻譜等優(yōu)勢得到眾多關(guān)注,可與傳統(tǒng)無線射頻(Radio Frequency,RF)通信形成互補(bǔ),并被認(rèn)為是解決未來移動通信系統(tǒng)中"最后一公里"問題的有效的技術(shù)之一。本文針對無線光通信系統(tǒng),著重研究室內(nèi)無線光通信系統(tǒng)中多色混合傳輸?shù)恼活l分復(fù)用(Orthogonal Frequency Division Multiplexing,OFDM)技術(shù),多用戶傳輸時的功率分配問題以及容量分析,以及室外無線光通信中RF/FSO(Free Space Optical,FSO)混合中繼傳輸技術(shù)。具體而言,論文的主要貢獻(xiàn)如下:首先,第二章針對采用RGBA-LED做光源的室內(nèi)無線光通信系統(tǒng),提出了一種新的OFDM方案�？紤]到照明和通信的雙重需求,新方案利用信號分離,削波偏置/放縮削波操作對信號進(jìn)行調(diào)整,使信號能夠在RGBA-LED上傳輸。然后,進(jìn)一步優(yōu)化削波偏置的偏置系數(shù)以及放縮削波的放縮系數(shù)。在接收端,提出一種直接檢測方案以恢復(fù)原始信號,并推導(dǎo)出正交幅度調(diào)制的誤比特率閉合表達(dá)式。為了提高系統(tǒng)性能,引入線性檢測算法來緩解多色間串?dāng)_的影響。此外,設(shè)計了一種低復(fù)雜度的并行干擾抵消算法以消除多色串?dāng)_。最后,在理想和實(shí)測光信道下對方案進(jìn)行仿真實(shí)驗(yàn)。理論分析和仿真結(jié)果表明,該方案在誤比特率上優(yōu)于傳統(tǒng)的OFDM方案。然后,第三章研究了室內(nèi)無線光通信系統(tǒng)中多用戶傳輸?shù)墓β史峙鋯栴}。為了同時兼顧照明和通信的需求,首先對系統(tǒng)的總功率以及單個LED的光功率進(jìn)行約束。在分析系統(tǒng)噪聲模型和接收信噪比的基礎(chǔ)上,得出系統(tǒng)容量的閉合表達(dá)式。然后基于功率約束條件,并以系統(tǒng)容量最大化為目標(biāo),將多用戶功率分配問題建模成優(yōu)化問題。對于同時傳輸模式,考慮到優(yōu)化問題的非凸性,首先采用梯度投影算法得到一個局部最優(yōu)解,然后利用凸松弛技術(shù)將非凸問題轉(zhuǎn)化成凸問題,并得到一個高質(zhì)量次優(yōu)解。對于輪詢模式,我們采用KKT(Karush-Kuhn-Tucker)條件,得到一個類似傳統(tǒng)注水算法的最優(yōu)解,該解具有上下削波的平方根形式。仿真結(jié)果表明,所提出的功率分配算法可提供比傳統(tǒng)平均功率分配算法更佳的性能。最后,第四章研究了室外無線光通信系統(tǒng)中RF/FSO混合傳輸技術(shù)及其性能。在該系統(tǒng)中,RF鏈路用來支持移動通信,而FSO用來承載移動通信基站間的回程鏈路,兩條鏈路通過固定增益放大轉(zhuǎn)發(fā)(Amplify-and-Forward,AF)中繼或可變增益AF中繼技術(shù)來實(shí)現(xiàn)互聯(lián)。對于兩種中繼方案,考慮到RF鏈路的非直達(dá)徑以及FSO鏈路中通用的大氣湍流模型,首先推導(dǎo)出系統(tǒng)端到端統(tǒng)計特性,如累積分布函數(shù)和矩生成函數(shù)的閉合表達(dá)式。隨后使用這些統(tǒng)計特性計算出多進(jìn)制相移鍵控,差分相移鍵控以及非相干頻移鍵控的閉合或近似平均誤符號率。其次,推導(dǎo)出高信噪比下不同調(diào)制方案的誤符號率的漸進(jìn)表達(dá)式,分析其分集度以及不同調(diào)制方案之間的性能差異,并得出一些有意義的結(jié)論。再次,從以上分析結(jié)果中進(jìn)一步推出系統(tǒng)FSO鏈路服從K分布以及Gamma-Gamma分布時不同調(diào)制方案誤符號率的閉合或近似表達(dá)式。最后,仿真結(jié)果驗(yàn)證了本章的理論分析結(jié)果和結(jié)論。
[Abstract]:Optical Wireless Communication (OWC) has attracted much attention due to its wide modulation bandwidth, high transmission rate, good confidentiality and no need for authorized spectrum. It can complement the traditional radio frequency (RF) communication and is considered as the solution to the "last mile" problem in future mobile communication systems. In this paper, we focus on the Orthogonal Frequency Division Multiplexing (OFDM) technology for indoor wireless optical communication systems, power allocation and capacity analysis for multiuser transmission, and RF / FSO (Free Space Opt) for outdoor wireless optical communication systems. Specifically, the main contributions of this paper are as follows: Firstly, in chapter 2, a new OFDM scheme is proposed for indoor wireless optical communication system using RGBA-LED as light source. Considering the dual requirements of lighting and communication, the new scheme uses signal separation, clipping bias/scaling clipping operation to perform signal separation. Then, the offset coefficient of clipping offset and the scaling coefficient of scaling clipping are further optimized. At the receiver, a direct detection scheme is proposed to recover the original signal, and the closed-form expression of BER of quadrature amplitude modulation is derived. In addition, a low complexity parallel interference cancellation algorithm is designed to eliminate the multicolor crosstalk. Finally, the scheme is simulated in ideal and measured optical channels. Theoretical analysis and simulation results show that the scheme is superior to the traditional OFDM scheme in bit error rate. Power allocation for multiuser transmission in indoor wireless optical communication systems. In order to meet both lighting and communication requirements, the total power of the system and the optical power of a single LED are constrained. To maximize the system capacity, the multi-user power allocation problem is modeled as an optimization problem. For simultaneous transmission mode, considering the non-convexity of the optimization problem, a local optimal solution is obtained by using gradient projection algorithm, and then the non-convex problem is transformed into a convex problem by using convex relaxation technique, and a high-quality problem is obtained. For the polling mode, we adopt the KKT (Karush-Kuhn-Tucker) condition to obtain an optimal solution similar to the traditional waterflooding algorithm, which has the square root form of up and down clipping. Simulation results show that the proposed power allocation algorithm can provide better performance than the traditional average power allocation algorithm. Finally, the fourth chapter studies the outdoor performance of the proposed algorithm. RF/FSO hybrid transmission technology and its performance in wireless optical communication systems. In this system, RF link is used to support mobile communications, while FSO is used to carry the return link between mobile communication base stations. Two links are interconnected by Amplify-and-Forward (AF) relay or variable gain AF relay technology. Considering the non-direct path of the RF link and the general atmospheric turbulence model in the FSO link, the closed-form expressions of the system end-to-end statistical characteristics, such as cumulative distribution function and moment generation function, are deduced. Then the multi-band phase shift keying, differential phase shift keying and incoherent frequency shift keying are calculated by using these statistical characteristics. Secondly, the asymptotic expression of symbol error rate for different modulation schemes under high signal-to-noise ratio is deduced, and the diversity and performance differences between different modulation schemes are analyzed. Finally, some meaningful conclusions are drawn. Thirdly, from the above analysis results, the system FSO links obey K distribution and Gamm are further deduced. Closed or approximate expressions of symbol error rate for different modulation schemes in a-Gamma distribution are given. Finally, the simulation results verify the theoretical analysis results and conclusions of this chapter.
【學(xué)位授予單位】：東南大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TN929.1

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 吳上才;;無線光通信系統(tǒng)的發(fā)展及其應(yīng)用初探[J];信息通信;2014年04期

2 魯輝,榮健;一種新型室內(nèi)無線光通信系統(tǒng)結(jié)構(gòu)[J];光通信技術(shù);2005年05期

3 胡貞輝;張繼生;;水下無線光通信系統(tǒng)模型分析[J];科技信息(科學(xué)教研);2007年29期

4 王紅星;胡昊;張鐵英;劉敏;許靜;;弱湍流中無線光通信系統(tǒng)差錯性能建模與仿真[J];系統(tǒng)仿真學(xué)報;2011年04期

5 彭小娟,陳曉天,劉世安;數(shù)字圖像無線光通信系統(tǒng)原理與設(shè)計[J];廣東工業(yè)大學(xué)學(xué)報;2003年04期

6 曹佳佳;聶平;劉偉;邰貴華;;無線光通信系統(tǒng)的發(fā)展及其應(yīng)用[J];才智;2010年01期

7 鄒宇;肖沙里;李冠華;霍暢;王兆浪;;紫外無線光通信系統(tǒng)研究[J];重慶工商大學(xué)學(xué)報(自然科學(xué)版);2012年07期

8 彭小娟;劉世安;熊春如;;無線光通信系統(tǒng)中的激光發(fā)射與接收技術(shù)[J];廣州航海高等�？茖W(xué)校學(xué)報;2009年04期

9 譚林偉,元秀華,黃德修;無線光通信系統(tǒng)中的光接收機(jī)設(shè)計[J];光學(xué)與光電技術(shù);2005年04期

10 崔煒;陳磊;;吉比特室內(nèi)無線光通信系統(tǒng)研究[J];半導(dǎo)體光電;2011年04期

相關(guān)會議論文 前4條

1 王建新;王盛華;宋雨;;分布式無線光通信系統(tǒng)的研究[A];全國第十二次光纖通信暨第十三屆集成光學(xué)學(xué)術(shù)會議論文集[C];2005年

2 湯俊雄;劉璐;羅文勇;;無線光通信系統(tǒng)器件與技術(shù)研究[A];第五屆全國光學(xué)前沿問題研討會論文摘要集[C];2001年

3 賈科軍;陳輝;薛建彬;王惠琴;;無線光通信系統(tǒng)性能分析方法研究[A];全國第15次光纖通信暨第16屆集成光學(xué)學(xué)術(shù)會議論文集[C];2011年

4 孫曉明;王紅星;朱銀兵;張鐵英;程剛;;DPIM無線光通信系統(tǒng)的性能特點(diǎn)分析[A];2006年全國光電技術(shù)學(xué)術(shù)交流會會議文集（E 光電子器件技術(shù)專題）[C];2006年

相關(guān)重要報紙文章 前1條

1 ;無線光接入技術(shù)開辟應(yīng)用新天地[N];人民郵電;2003年

相關(guān)博士學(xué)位論文 前2條

1 張明軒;無線可見光通信關(guān)鍵技術(shù)研究[D];東南大學(xué);2016年

2 孔磊;無線光通信系統(tǒng)中混合傳輸技術(shù)與性能分析[D];東南大學(xué);2016年

相關(guān)碩士學(xué)位論文 前10條

1 張穎;M湍流無線光通信系統(tǒng)的性能分析[D];南京航空航天大學(xué);2014年

2 楊本圣;基于MPPM無線光通信系統(tǒng)在湍流信道下的誤符號率性能研究[D];西安電子科技大學(xué);2015年

3 吳健;水下無線光通信系統(tǒng)的研究和實(shí)現(xiàn)[D];廈門大學(xué);2014年

4 王曉穎;圖像無線光通信系統(tǒng)光接收機(jī)設(shè)計[D];長春理工大學(xué);2008年

5 鑒佃軍;無線光通信系統(tǒng)的大氣信道特性研究[D];西安電子科技大學(xué);2008年

6 孟┤，

本文編號：2245205