本文選題：多載波 + 信噪比�。� 參考：《北京郵電大學》2015年碩士論文

【摘要】：隨著信息化的不斷深入,人類對網(wǎng)絡的需求不斷增加,通信業(yè)務呈現(xiàn)爆炸式增長。不斷增加的設備數(shù)量、更多的互聯(lián)網(wǎng)用戶、更快的寬帶速度、更多視頻導致了IP流量的暴增,這些因素加大了對骨干網(wǎng)傳輸容量和傳輸速率的要求。 為了提高傳輸容量及效率,傳輸系統(tǒng)在發(fā)送端大多采用多個激光器,然而由于各個激光器指標不能做到完全一致,使實驗系統(tǒng)穩(wěn)定性受到影響；而且大量激光器的使用,也不利于傳輸系統(tǒng)的商用化。因此使用穩(wěn)定的多載波光源做發(fā)射機成為了研究熱點。在眾多產(chǎn)生多載波光源的方案中,基于循環(huán)頻移結(jié)構(gòu)的方案產(chǎn)生的多載波光源具有穩(wěn)定、平坦度高的優(yōu)點,且產(chǎn)生子載波數(shù)量多,非常適合太比特傳輸系統(tǒng),成為主要研究方案；但是由于其循環(huán)結(jié)構(gòu)特性,造成噪聲累積,降低了產(chǎn)生多載波光源的信噪比,影響多載波光源的質(zhì)量。因此如何進一步提高信噪比以適用于高速傳輸系統(tǒng)成為了重點研究方向。 由于全球互聯(lián)網(wǎng)用戶激增及用戶使用無線接入技術(shù)的普及,現(xiàn)有無線接入技術(shù)在速率、容量、安全性、復用性等諸多方面將遭遇嚴重挑戰(zhàn)�？梢姽馔ㄐ偶夹g(shù)作為一種新興的無線接入技術(shù),由于其通信與能量復用的特點,擁有廣闊的應用前景；與此同時兼具波段免費、方便安全的特性,越來越受到學者們重視。 當前可見光通信系統(tǒng)中主要利用LED作為發(fā)射機,完成通信與照明功能;接收端采用光電檢測器接收光信號,僅僅完成通信功能。這種是一種功能不對稱的系統(tǒng)結(jié)構(gòu),在造成能量的浪費同時又難以實用化,限制了可見光通信系統(tǒng)研究的發(fā)展。為解決以上問題,設計易于商用化的新型可見光通信系統(tǒng)結(jié)構(gòu),成為了重要研究方向 根據(jù)以上問題,本論文將從多載波和可見光通信系統(tǒng)兩部分展開研究工作。主要工作分為以下幾個方面： 1.從有線和無線兩方面闡述光通信的發(fā)展現(xiàn)狀和研究意義。 2.分析基于循環(huán)頻移結(jié)構(gòu)產(chǎn)生多載波光源方案的原理及系統(tǒng)結(jié)構(gòu),同時從激光器線寬和ASE噪聲累積兩個方面研究了噪聲累積對多載波光源性能的影響。 3.對時延干涉儀的基本原理進行研究,進而提出了產(chǎn)生多載波光源的改進型方案。依次從理論分析、仿真驗證、實驗搭建完成對改進型結(jié)構(gòu)功能實現(xiàn)的驗證工作。 4.研究可見光通信基礎理論及以太網(wǎng)和串口通信協(xié)議。仿真驗證基于FPGA的MAC控制器開發(fā)和基于FPGA的串口通信開發(fā),并將串口通信協(xié)議應用于可見光通信系統(tǒng)中。 5.分析太陽能電池工作原理,由此提出了功能對稱的可見光通信系統(tǒng),進而搭建實驗平臺驗證系統(tǒng)方案可行。 綜上所述,本論文將分別研究多載波和可見光通信系統(tǒng)兩部分。多載波方面主要研究了基于循環(huán)頻移結(jié)構(gòu)產(chǎn)生多載波光源的方案原理,噪聲累積對所產(chǎn)生多載波性能的影響及影響噪聲累積的主要因素；通過分析研究時延干涉儀特性,提出了一種改進型多載波產(chǎn)生方案,有效提高了多載波光源質(zhì)量。可見光通信系統(tǒng)方面研究了系統(tǒng)基礎理論及相關通信協(xié)議,完成了基礎可見光通信系統(tǒng)搭建；進而研究太陽能電池原理并將其應用于可見光通信系統(tǒng)中,實現(xiàn)收發(fā)兩端均能夠達到通信和能量復用功能,實驗驗證了提出的功能對稱的可見光通信系統(tǒng)方案可行性。
[Abstract]:With the deepening of the information technology , the demand of human to the network is constantly increasing , and the communication service presents explosive growth . The increasing number of devices , more Internet users , faster broadband speed , and more video result in an increase in IP traffic . These factors increase the demand for the transmission capacity and transmission rate of the backbone network .

in ord to improve that transmission capacity and efficiency , a plurality of lasers are adopt at the transmitting end of the transmission system , but the stability of the experimental system is influenced due to the fact that the indexes of each laser cannot be completely consistent ;
in the scheme of generating the multi - carrier light source , the multi - carrier light source generated by the scheme based on the cyclic frequency shift structure has the advantages of stable and flatness and large number of sub - carriers , is very suitable for the terahertz transmission system and becomes the main research scheme ;
However , due to its cyclic structure characteristics , noise accumulation is reduced , the signal - to - noise ratio of multi - carrier light source is reduced , and the quality of multi - carrier light source is affected . Therefore , it is important to improve the signal - to - noise ratio so as to be suitable for high - speed transmission system .

Due to the proliferation of global Internet users and the popularization of wireless access technologies by users , the existing wireless access technology will encounter serious challenges in many aspects , such as rate , capacity , security and reusability . Visible light communication technology is a new wireless access technology . Due to its characteristics of communication and energy reuse , it has a wide application prospect .
At the same time , it has the characteristics of free , convenient and safe band , and more and more scholars pay more attention .

In the current visible light communication system , the LED is mainly used as a transmitter to finish the communication and lighting function , and the receiving end adopts a photoelectric detector to receive the optical signal , and only completes the communication function .

According to the above problems , the thesis will carry out research work from two parts of multi - carrier and visible light communication system . The main work is divided into the following aspects :

1 . The development status and significance of optical communication are discussed from both wired and wireless aspects .

2 . The principle and system structure of multi - carrier light source scheme are analyzed based on the cyclic frequency shift structure , and the influence of noise accumulation on the performance of multi - carrier light source is studied from two aspects of laser linewidth and ASE noise accumulation .

3 . The basic principle of the time delay interferometer is studied , and the improved scheme for generating the multi - carrier light source is put forward . From the theoretical analysis , the simulation verification and the experiment , the verification of the function of the improved structure is completed .

4 . Research the basic theory of visible light communication and the communication protocol of Ethernet and serial port . Simulation verifies the development of MAC controller based on FPGA and serial communication development based on FPGA , and applies serial communication protocol to visible light communication system .

5 . The working principle of the solar cell is analyzed , and the function - symmetrical visible - light communication system is put forward , and then the scheme of the experiment platform verification system is feasible .

In conclusion , this thesis will study two parts of multi - carrier and visible - light communication systems , which mainly study the scheme principle of multi - carrier light source based on cyclic frequency shift structure , the influence of noise accumulation on multi - carrier performance and the main factors affecting noise accumulation .
By analyzing the characteristics of delay interferometer , an improved multi - carrier generation scheme is proposed , which improves the quality of multi - carrier light source effectively .
In this paper , the principle of solar cell and its application in the visible light communication system are studied . The communication and energy multiplexing function can be realized at both ends of the transceiver , and the feasibility of the proposed scheme is verified .
【學位授予單位】：北京郵電大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN929.1

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相關期刊論文 前3條

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2 鄒書敏;王一光;邵宇豐;張俊文;余建軍;遲楠;;Generation of coherent optical multi-carriers using concatenated,dual-drive Mach-Zehnder and phase modulators[J];Chinese Optics Letters;2012年07期

3 孟婉;席麗霞;張曉光;林嘉川;田鳳;涂昊;張霞;;Theoretical analysis of the performance of a single side band multicarrier source based on a re-circulating frequency shifter influenced by an optical bandpass filter[J];Chinese Optics Letters;2013年09期

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本文編號：2100403