高速多色可见光通信系统关键技术研究

发布时间：2018-07-18 12:58

【摘要】：近年来,随着移动通信技术的飞速发展,移动通信用户不断增长,无线通信所占用的无线电波频带资源愈渐拥挤。光波的频率更高、波长更短,具有频带宽、通信容量大、传输速率高、抗电磁干扰能力强和绿色环保等优点,使得可见光通信成为当前室内短距离无线通信传输方案的研究热点。本文针对室内多色可见光通信系统中的关键技术进行了研究,主要包括HARQ技术和AMC技术。本文结合可见光信道的特性,选择出适合的方案,且结合实测信道进行仿真,验证了算法的性能。最后给出了室内多色可见光通信演示系统的FPGA实现方案。首先,本文主要描述了可见光通信技术的研究背景。同时也对国内与国外可见光通信的最新研究现状进行了概述。接着对室内可见光通信系统进行介绍,简述了可见光通信的基本原理,主要包括可见光通信的系统模型、发射电路和接收电路原理等,并介绍了室内可见光通信系统的基本信道模型。进而给出了本文研究的基于DCO-OFDM的可见光通信系统原理和多色可见光通信系统原理。随后,本文探讨了室内可见光通信HARQ技术方案。主要先介绍了 HARQ技术,包括ARQ技术与FEC技术。接着研究了适合室内可见光通信系统的HARQ方案,比较了两种方案的差别。方案一是基于I型HARQ的可见光方案,方案二是基于Chase合并HARQ的可见光方案,并对两个方案的性能进行仿真分析。结果表明:方案一相比于不使用HARQ的可见光通信系统,FER性能更优,但通过率性能很接近。而方案二相比于方案一,充分利用接收到的信息,虽然增加了接收方缓存以及系统复杂度,但是传输性能大大提升。接着,本文研究了室内可见光通信AMC技术方案。首先描述自适应技术中的算法基础和自适应OFDM系统的原理。接着对经典的自适应算法进行仿真对比分析。然后介绍了自适应调制编码(AMC)技术。在此基础上提出了一种适用于可见光通信系统的AMC实现方案:基于SNR门限的改进的简单分组AMC算法。结果表明:其相比于原先的简单分组自适应算法,虽然增加了一定的计算复杂度,但传输速率得到进一步的提升,系统性能也进一步提高。最后在室内可见光通信系统硬件平台对方案进行验证,验证结果符合理论分析。最后,在前几章可见光基本理论的基础上,介绍了本课题的室内可见光通信系统硬件演示平台。首先,对室内可见光通信系统的硬件平台进行概述,包括平台的整体框架模型。然后对室内可见光通信系统的FPGA设计方案进行描述,主要描述了 FPGA发送与接收的各个基带处理模块的数据处理流程。最后对硬件演示平台进行实物成果展示,介绍了各个硬件设备的型号和参数。
[Abstract]:In recent years, with the rapid development of mobile communication technology, mobile communication users continue to grow, wireless communication occupies more and more crowded radio frequency band resources. The light wave has the advantages of higher frequency, shorter wavelength, higher frequency bandwidth, larger communication capacity, higher transmission rate, stronger anti-electromagnetic interference ability and green environment protection, etc. It makes visible light communication become the research hotspot of indoor short-range wireless communication. This paper studies the key technologies of indoor multicolor visible light communication system, including HARQ technology and AMC technology. According to the characteristics of visible light channel, a suitable scheme is selected in this paper, and the performance of the algorithm is verified by the simulation of the measured channel. Finally, the FPGA implementation scheme of indoor multicolor visible light communication demonstration system is given. Firstly, this paper mainly describes the research background of visible light communication technology. At the same time, the latest research status of visible light communication at home and abroad is summarized. Secondly, the paper introduces the indoor visible light communication system, and introduces the basic principle of the visible light communication, including the system model of the visible light communication, the principle of the transmitting circuit and the receiving circuit, etc. The basic channel model of indoor visible light communication system is also introduced. The principle of visible light communication system based on DCO-OFDM and the principle of multicolor visible light communication system are presented. Then, this paper discusses the HARQ technology scheme of indoor visible light communication. This paper introduces HARQ technology, including ARQ technology and FEC technology. Then the HARQ scheme suitable for indoor visible light communication system is studied and the differences between the two schemes are compared. The first scheme is a visible light scheme based on type I HARQ and the other is a visible light scheme based on Chase merging HARQ. The performance of the two schemes is simulated and analyzed. The results show that the performance of the first scheme is better than that of the visible light communication system without HARQ, but the pass rate is very close. Compared with the first scheme, the second scheme makes full use of the received information. Although it increases the cache of the receiver and the complexity of the system, the transmission performance is greatly improved. Then, this paper studies the AMC technology scheme of indoor visible light communication. Firstly, the algorithm foundation of adaptive OFDM system and the principle of adaptive OFDM system are described. Then the classical adaptive algorithm is simulated and analyzed. Then the adaptive modulation coding (AMC) technology is introduced. On this basis, an AMC implementation scheme for visible light communication systems is proposed: an improved simple packet AMC algorithm based on SNR threshold. The results show that compared with the original simple packet adaptive algorithm, it increases the computational complexity, but the transmission rate is further improved and the system performance is further improved. Finally, the scheme is verified on the hardware platform of indoor visible light communication system, and the results agree with the theoretical analysis. Finally, based on the basic theory of visible light in the previous chapters, this paper introduces the hardware demonstration platform of indoor visible light communication system. Firstly, the hardware platform of indoor visible light communication system is summarized, including the whole frame model of the platform. Then it describes the FPGA design of indoor visible light communication system, mainly describes the data processing flow of each baseband processing module sent and received by FPGA. Finally, the hardware demonstration platform is presented, and the models and parameters of each hardware device are introduced.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.1

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