空移键控调制在可见光通信系统中的应用研究

发布时间：2018-02-13 18:53

本文关键词： 空移键控调制室内可见光通信系统改进方案　出处：《西南交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：可见光通信技术是一种新兴的在LED室内照明基础上发展起来的无线光通信技术,利用白光LED响应时间短、调制速率高的特性,设计出了室内白光LED无线通信系统。白光LED无线通信系统可以同时用于照明和通信,既节能又减少了重复投资,因此,白光LED通信系统具有很大的研究意义,被公认为是一种新兴的短距离无线通信系统。空移键控(SSK)是近年来提出的一种新的调制方式,可以避免天线间干扰的MIMO传输技术。传统多天线系统在所有天线上传输信号,会在天线之间造成干扰。SSK在一个时隙中根据传输信息在多根天线中选择一根发射信号,从而避免了不同天线间的干扰,同时其信息仅由选择的天线编号携带,不用进行传统调制,接收端根据不同天线发射时的独特多径特性来判断天线编号,得到发射信息。可见光通信的现有的调制方式少且在频带利用率和功率有效性上都有一定缺点,而且受到室内信道多径效应的影响严重。本课题拟借鉴SSK的思路,将其加入到室内可见光通信系统中,作为该通信系统的一种调制技术,不仅提高了频带利用率和能源利用率,还充分利用室内信道的多径效应。论文主要研究了空移键控调制系统和基于白光LED的室内可见光通信系统。本文首先分析了SSK调制系统的调制原理以及接收端的检测方式,其次分析了可见光通信系统的室内信道,得到可行的信道的数学模型。然后将SSK调制系统应用到室内可见光通信系统中,利用MATLAB仿真,可知此应用可行。然而,经过多次仿真发现,当接收端与多个发射端距离相似时,系统性能极差,为此,本文引入广义空移键控调制(GSSK)和自适应控制来解决此问题。最后,本文又在信道条件不准确的条件下,对系统进行了仿真分析。
[Abstract]:Visible light communication technology is a new wireless optical communication technology developed on the basis of LED indoor lighting. The white light LED has the characteristics of short response time and high modulation rate. The indoor white light LED wireless communication system is designed. The white light LED wireless communication system can be used for both lighting and communication, which not only saves energy but also reduces the repeated investment. Therefore, the white light LED communication system has great research significance. It is recognized as a new type of short range wireless communication system. Air shift keying (SSK) is a new modulation technique proposed in recent years, which can avoid interantenna interference (MIMO). Traditional multi-antenna systems transmit signals on all antennas. It causes interference between antennas. SSK selects one of the multiple antennas in one slot according to the transmission information, thus avoiding interference between different antennas, and the information is carried only by the selected antenna number. Without traditional modulation, the receiver determines the antenna number according to the unique multipath characteristics of different antennas. The transmission information is obtained. The existing modulation methods of visible light communication have some shortcomings in frequency band efficiency and power efficiency, and are seriously affected by the multipath effect of indoor channel. This paper intends to draw lessons from the idea of SSK. As a modulation technique of indoor visible light communication system, it not only improves the efficiency of frequency band and energy, but also makes full use of the multipath effect of indoor channel. This paper mainly studies the air-shift keying modulation system and the indoor visible light communication system based on white-light LED. Firstly, the modulation principle of the SSK modulation system and the detection method of the receiver are analyzed. Secondly, the indoor channel of the visible light communication system is analyzed, and the feasible mathematical model of the channel is obtained. Then, the SSK modulation system is applied to the indoor visible light communication system, and the MATLAB simulation shows that the application is feasible. After many simulations, it is found that the performance of the system is extremely poor when the distance between the receiver and multiple transmitters is similar. In this paper, the generalized spatial shift keying modulation (GSSK) and adaptive control are introduced to solve this problem. In this paper, the system is simulated and analyzed under the condition of inaccurate channel conditions.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1

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