室内可见光通信系统中多用户接入技术研究

发布时间：2018-06-26 03:10

本文选题：室内可见光通信 + 多址接入协议　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：可见光通信(VLC)是近年来迅速发展的一种新型无线通信方式,它将照明与通信相结合,在LED照明设施上增加数据传输功能,通过LED光源高速明暗闪烁来传递信息。相比射频无线通信,室内可见光通信具有可利用带宽大且不用授权、不会产生电磁辐射、安全性高等特点,可以应用于医院、加油站、机舱等要求电磁干扰小,安全性要求高的场所。目前,室内VLC组网问题是研究的热点之一,但在多用户接入的情况下,由于LED终端上可集成的光探测器数目有限,多个用户同时请求接入时会产生碰撞,降低网络的通信效率。因此,如何避免碰撞,有效的完成用户接入,是室内VLC组网急需解决的问题。针对上述问题,本文提出了一种混合多址接入协议—h_SMA/TDMA协议,有效地解决了通信时多用户接入问题。本文首先介绍了室内可见光通信的基本理论,分析了当前VLC研究的关键技术。接着介绍了基本的多址接入协议,分析了各协议的优点和不足。在此基础上,本文提出了CSMA/TDMA协议,详细阐述了协议的帧结构,然后对CSMA时段与TDMA时段协议的具体运行过程和其中的问题进行了探讨,并对混合协议的相关参数进行了理论分析和推导,得到了相关性能指标的表达式。最后,针对提出的协议,对碰撞概率、CSMA时段持续时间及各种情况下的系统吞吐量进行了仿真和分析。结果表明,该协议能够很好地解决可见光通信中多用户的接入问题,证明该协议是合理可行性。
[Abstract]:Visible-light communication (VLC) is a new wireless communication mode developed rapidly in recent years. It combines lighting with communication, adds data transmission function on LED lighting facilities, and transmits information by LED light source high speed light and dark flicker. Compared with radio frequency wireless communication, indoor visible light communication has the advantages of large bandwidth, no authorization, no electromagnetic radiation, high safety and so on. It can be used in hospitals, gas stations, engine rooms and so on. A place with high safety requirements. At present, the problem of indoor VLC networking is one of the hot topics. However, in the case of multi-user access, due to the limited number of integrated photodetectors on LED terminals, multiple users may collide when requesting access at the same time, and reduce the communication efficiency of the network. Therefore, how to avoid collision and effectively complete user access is an urgent problem for indoor VLC network. In order to solve the above problems, a hybrid multiple access protocol (HMA / TDMA) is proposed in this paper, which effectively solves the problem of multiuser access in communication. In this paper, the basic theory of indoor visible light communication is introduced, and the key technologies of VLC research are analyzed. Then the basic multiple access protocol is introduced, and the advantages and disadvantages of each protocol are analyzed. On this basis, this paper puts forward CSMA / TDMA protocol, describes the frame structure of CSMA / TDMA protocol in detail, and then discusses the specific running process and problems of CSMA and TDMA period protocols. The related parameters of the hybrid protocol are theoretically analyzed and deduced, and the expression of the related performance index is obtained. Finally, for the proposed protocol, the collision probability and the duration of CSMA and the system throughput under various conditions are simulated and analyzed. The results show that the protocol can solve the problem of multi-user access in visible light communication, and proves that the protocol is reasonable and feasible.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.1

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