面向无线接入的光载无线链路设计
发布时间：2019-05-08 01:39
【摘要】：随着通信技术的快速发展,各种新兴业务的不断涌现,带宽的需求不断增加,对现有通信系统提出了严峻的挑战。而RoF技术结合了光纤通信的带宽优势和无线通信的移动优势,成为解决这一问题的潜在解决方案。另一方面可以通过提升载波频率,发掘利用未开发的毫米波频段,避免频谱拥塞的同时,增加了通信带宽,从而解决带宽瓶颈的问题。因此同时结合上述两种方案的优势,即在毫米波无线接入网中利用RoF技术就具有非常重大的意义。本文首先概述了 RoF系统的起源、研究背景、优势、应用领域以及国内外对该技术的研究现状。然后详细分析了 RoF系统的基本结构,并且理论推导了相位调制器和强度调制器的产生机理,阐述了双边带调制、单边带调制和载波抑制调制的实现原理。同时,对于RoF系统中的频率转换,介绍了采用光外差法和OEO (Optoelectronic Oscillator)技术对信号进行上变频。同时介绍了采用包络检波的方法对接收端的信号下变频。基于上述的理论基础,本文在RoF系统设计方面主要做了以下工作:(1)研究并且实验验证了一种基于OEO的频率可调谐的光载无线接入方案。通过在OEO结构中融合可调谐的微波光子滤波器来实现系统的可调谐性能。而微波光子滤波器主要是基于相移光纤布拉格光栅(PS-FBG)的陷波滤波。实验中实现了 1.25Gbit/s的OOK信号的传输,产生的载波的可调谐范围为8-14.5GHz。通过将OEO融合进RoF系统的发射端,其振荡产生的载波频率可以便捷的通过调节输入光信号的波长来控制,无线接收端采用包络检波的方法来实现信号的解调。因此,整体系统中均不需要外置的微波源进行信号的上下变频,降低了系统成本。(2)鉴于长距离隧道内复杂的无线传输环境,研究了一种基于波分复用无源光网络的光载无线(RoF)隧道通信系统。该系统采用波分复用技术实现不同业务在光域的物理隔离,协同分布式天线技术在隧道内部提供高频无线接入,在提升系统带宽的同时解决了隧道内部高频信号急剧衰减的问题。最后通过实验搭建了全双工的光载无线实验平台,实现了用光学的方法产生和传输了载频为24G的16/64QAM矢量信号。(3)将多载波技术与RoF技术相结合,基于optisystem 14软件仿真搭建了 OFDM-RoF光载无线系统。在此基础上,使用商业的4GVoLTE语音系统,实验搭建了 VoLTE-RoF演示验证平台。
[Abstract]:With the rapid development of communication technology, the emergence of a variety of new services, the increasing demand for bandwidth, the existing communications systems pose a serious challenge. The RoF technology combines the bandwidth advantage of optical fiber communication with the mobile advantage of wireless communication, and becomes a potential solution to this problem. On the other hand, the bandwidth bottleneck can be solved by raising the carrier frequency, exploiting the undeveloped millimeter wave frequency band, avoiding spectrum congestion and increasing the communication bandwidth. Therefore, combining the advantages of the two schemes at the same time, it is of great significance to utilize RoF technology in millimeter wave wireless access network. In this paper, the origin, research background, advantages, application fields and research status of RoF system at home and abroad are summarized. Then, the basic structure of RoF system is analyzed in detail, and the generation mechanism of phase modulator and intensity modulator is deduced theoretically, and the realization principles of two-side band modulation, one-sided band modulation and carrier suppression modulation are expounded. At the same time, for the frequency conversion in RoF system, the optical heterodyne method and OEO (Optoelectronic Oscillator) technology are introduced to up-convert the signal. At the same time, the method of envelope detection is introduced to down-convert the receiver signal. Based on the above-mentioned theoretical basis, the main work of this paper is as follows: (1) A frequency-tunable optical-borne wireless access scheme based on OEO is studied and verified experimentally. The main work of this paper is as follows: (1) the design of RoF system is as follows: 1. The tunable performance of the system is realized by combining the tunable microwave photonic filter in the OEO structure. Microwave photonic filter is mainly based on phase-shifted fiber Bragg grating (PS-FBG) notch filter. In the experiment, the transmission of the OOK signal of 1.25Gbit/s is realized, and the tunable range of the generated carrier is 8 ~ 14.5GHz. By merging the OEO into the transmitter of the RoF system, the carrier frequency generated by the oscillation can be easily controlled by adjusting the wavelength of the input optical signal, and the wireless receiver uses the envelope detection method to realize the demodulation of the signal. Therefore, no external microwave source is needed in the whole system, which reduces the cost of the system. (2) in view of the complex wireless transmission environment in the long-distance tunnel, A optical-borne wireless (RoF) tunnel communication system based on wavelength division multiplexing (WDM) passive optical network is studied in this paper. The system uses wavelength division multiplexing technology to realize physical isolation of different services in optical domain, and cooperative distributed antenna technology to provide high frequency wireless access in the tunnel. While raising the bandwidth of the system, the problem of the sharp attenuation of the high frequency signal in the tunnel is solved at the same time. Finally, a full-duplex optical-borne wireless experimental platform is built, and the 16/64QAM vector signal with the carrier frequency of 24G is generated and transmitted by optical method. (3) the multicarrier technology is combined with the RoF technology, and the optical signal is generated and transmitted by optical method. (3) the multi-carrier technology is combined with the RoF technology. Based on optisystem 14 software, a OFDM-RoF optical carrier wireless system is built. On this basis, using the commercial 4GVoLTE voice system, the VoLTE-RoF demonstration verification platform is built.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925.93
本文编号：2471519
[Abstract]:With the rapid development of communication technology, the emergence of a variety of new services, the increasing demand for bandwidth, the existing communications systems pose a serious challenge. The RoF technology combines the bandwidth advantage of optical fiber communication with the mobile advantage of wireless communication, and becomes a potential solution to this problem. On the other hand, the bandwidth bottleneck can be solved by raising the carrier frequency, exploiting the undeveloped millimeter wave frequency band, avoiding spectrum congestion and increasing the communication bandwidth. Therefore, combining the advantages of the two schemes at the same time, it is of great significance to utilize RoF technology in millimeter wave wireless access network. In this paper, the origin, research background, advantages, application fields and research status of RoF system at home and abroad are summarized. Then, the basic structure of RoF system is analyzed in detail, and the generation mechanism of phase modulator and intensity modulator is deduced theoretically, and the realization principles of two-side band modulation, one-sided band modulation and carrier suppression modulation are expounded. At the same time, for the frequency conversion in RoF system, the optical heterodyne method and OEO (Optoelectronic Oscillator) technology are introduced to up-convert the signal. At the same time, the method of envelope detection is introduced to down-convert the receiver signal. Based on the above-mentioned theoretical basis, the main work of this paper is as follows: (1) A frequency-tunable optical-borne wireless access scheme based on OEO is studied and verified experimentally. The main work of this paper is as follows: (1) the design of RoF system is as follows: 1. The tunable performance of the system is realized by combining the tunable microwave photonic filter in the OEO structure. Microwave photonic filter is mainly based on phase-shifted fiber Bragg grating (PS-FBG) notch filter. In the experiment, the transmission of the OOK signal of 1.25Gbit/s is realized, and the tunable range of the generated carrier is 8 ~ 14.5GHz. By merging the OEO into the transmitter of the RoF system, the carrier frequency generated by the oscillation can be easily controlled by adjusting the wavelength of the input optical signal, and the wireless receiver uses the envelope detection method to realize the demodulation of the signal. Therefore, no external microwave source is needed in the whole system, which reduces the cost of the system. (2) in view of the complex wireless transmission environment in the long-distance tunnel, A optical-borne wireless (RoF) tunnel communication system based on wavelength division multiplexing (WDM) passive optical network is studied in this paper. The system uses wavelength division multiplexing technology to realize physical isolation of different services in optical domain, and cooperative distributed antenna technology to provide high frequency wireless access in the tunnel. While raising the bandwidth of the system, the problem of the sharp attenuation of the high frequency signal in the tunnel is solved at the same time. Finally, a full-duplex optical-borne wireless experimental platform is built, and the 16/64QAM vector signal with the carrier frequency of 24G is generated and transmitted by optical method. (3) the multicarrier technology is combined with the RoF technology, and the optical signal is generated and transmitted by optical method. (3) the multi-carrier technology is combined with the RoF technology. Based on optisystem 14 software, a OFDM-RoF optical carrier wireless system is built. On this basis, using the commercial 4GVoLTE voice system, the VoLTE-RoF demonstration verification platform is built.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925.93
【引证文献】
相关硕士学位论文 前2条
1 荆士泉;基于光载无线技术的工业网关研究与设计[D];湖南工业大学;2018年
2 庄云圣;基于光载无线技术的多业务传输系统研究[D];西南交通大学;2018年
，本文编号：2471519
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