车联网系统中的基带信号处理技术研究和FPGA实现
发布时间：2019-03-19 10:39
【摘要】：随着社会的快速发展,人们对汽车的需求不断的增长,道路通行的压力也随之增加。日益凸显的交通安全隐患,使智能化的汽车服务备受各方的青睐,汽车互联将是未来汽车电子行业发展的趋势。提供全方位的消息共享服务和实时交通状况,是车联网最基本的功能。车联网所提供的这些服务不仅仅只是融合了通信、服务、终端硬件的综合体,它更是汽车商业链的催化剂。本论文以车联网系统为研究的主体,针对车联网系统中基带处理的部分问题展开研究,这对将来车联网系统的实际应用有着重要的意义。本论文主要完成的工作内容如下:本文首先详细叙述了车联网系统物理层使用的OFDM技术的基本原理和特点。深入分析了同步误差对OFDM系统造成的影响,并且利用仿真实验给出了误差验证结果。此外,针对车联网系统中媒体访问控制使用的防碰撞机制,在大量请求接入节点的环境中会出现低吞吐率的问题,做出了相应的研究分析。紧接着,本文以经典的SchmidlCox算法为基础,重点研究了几种同步算法。通过详细的公式演算和推导,分析出SchmidlCox算法度量曲线存在平台区的缺点,以及Minn算法的多侧峰问题。通过分析上述算法存在的缺陷,本文通过设计新的训练符号提出了改进的基于训练符号的同步算法。该改进的算法不仅消除了平台区的影响,而且消除了多侧峰的干扰。提高了符号定时的准确性。最后通过仿真得到验证。然后,本文通过仿真分析了存在大量请求接入节点时,系统吞吐率下降的情况。为解决这个问题,本文将正交频分多址复用的技术使用到车联网系统的媒体接入层中,通过设计满足基于OFDMA的CSMA/CA机制的接收机的模块,仿真验证了该方法可以提高系统的吞吐率。最后,本文将车联网系统设计的各个模块使用FPGA来实现。FPGA作为现在通信电子技术,以其高效、大数据运算等特点被广泛的应用。文章给出了发射机和接收机的核心模块设计和部分优化算法。以实际应用的FPGA仿真完成车联网通信模块,使得本文的设计更具有说服力。
[Abstract]:With the rapid development of society, the demand for cars is increasing, and the pressure of road passage is also increasing. Because of the hidden trouble of traffic safety, the intelligent automobile service is favored by all parties, and the automobile interconnection will be the development trend of the automobile electronics industry in the future. To provide a full range of information sharing services and real-time traffic conditions, is the most basic function of the car network. These services are not only a combination of communications, services, and terminal hardware, but also a catalyst for the automotive business chain. In this paper, the main body of this paper is the vehicle networking system, aiming at some problems of baseband processing in the vehicle networking system, which is of great significance to the practical application of the vehicle networking system in the future. The main contents of this paper are as follows: firstly, the basic principles and characteristics of OFDM technology used in the physical layer of the vehicle networking system are described in detail. The influence of synchronization error on OFDM system is analyzed deeply, and the result of error verification is given by simulation experiment. In addition, aiming at the anti-collision mechanism used in the media access control of the vehicle networking system, the problem of low throughput will appear in the environment of a large number of request access nodes, and the corresponding research and analysis are made. Then, based on the classical SchmidlCox algorithm, this paper focuses on several synchronization algorithms. Based on the detailed formula calculus and derivation, the shortcomings of the SchmidlCox algorithm in the platform region and the multi-side peak problem of the Minn algorithm are analyzed. By analyzing the shortcomings of the above algorithms, this paper proposes an improved synchronization algorithm based on training symbols by designing new training symbols. The improved algorithm not only eliminates the influence of platform area, but also eliminates the interference of multi-side peaks. The accuracy of symbol timing is improved. Finally, it is verified by simulation. Then, the throughput of the system is analyzed by simulation when there are a large number of request access nodes. In order to solve this problem, the orthogonal frequency division multiple access (OFDM) technology is used in the media access layer of the vehicle networking system, and the receiver module which satisfies the CSMA/CA mechanism based on OFDMA is designed. Simulation results show that the proposed method can improve the throughput of the system. In the end, every module of the vehicle networking system is implemented by FPGA. As a communication electronic technology, FPGA is widely used for its high efficiency, big data operation and other characteristics. The core module design and partial optimization algorithm of transmitter and receiver are given in this paper. The design of this paper is more persuasive to use the FPGA simulation to complete the communication module of the vehicle network.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U495
本文编号：2443443
[Abstract]:With the rapid development of society, the demand for cars is increasing, and the pressure of road passage is also increasing. Because of the hidden trouble of traffic safety, the intelligent automobile service is favored by all parties, and the automobile interconnection will be the development trend of the automobile electronics industry in the future. To provide a full range of information sharing services and real-time traffic conditions, is the most basic function of the car network. These services are not only a combination of communications, services, and terminal hardware, but also a catalyst for the automotive business chain. In this paper, the main body of this paper is the vehicle networking system, aiming at some problems of baseband processing in the vehicle networking system, which is of great significance to the practical application of the vehicle networking system in the future. The main contents of this paper are as follows: firstly, the basic principles and characteristics of OFDM technology used in the physical layer of the vehicle networking system are described in detail. The influence of synchronization error on OFDM system is analyzed deeply, and the result of error verification is given by simulation experiment. In addition, aiming at the anti-collision mechanism used in the media access control of the vehicle networking system, the problem of low throughput will appear in the environment of a large number of request access nodes, and the corresponding research and analysis are made. Then, based on the classical SchmidlCox algorithm, this paper focuses on several synchronization algorithms. Based on the detailed formula calculus and derivation, the shortcomings of the SchmidlCox algorithm in the platform region and the multi-side peak problem of the Minn algorithm are analyzed. By analyzing the shortcomings of the above algorithms, this paper proposes an improved synchronization algorithm based on training symbols by designing new training symbols. The improved algorithm not only eliminates the influence of platform area, but also eliminates the interference of multi-side peaks. The accuracy of symbol timing is improved. Finally, it is verified by simulation. Then, the throughput of the system is analyzed by simulation when there are a large number of request access nodes. In order to solve this problem, the orthogonal frequency division multiple access (OFDM) technology is used in the media access layer of the vehicle networking system, and the receiver module which satisfies the CSMA/CA mechanism based on OFDMA is designed. Simulation results show that the proposed method can improve the throughput of the system. In the end, every module of the vehicle networking system is implemented by FPGA. As a communication electronic technology, FPGA is widely used for its high efficiency, big data operation and other characteristics. The core module design and partial optimization algorithm of transmitter and receiver are given in this paper. The design of this paper is more persuasive to use the FPGA simulation to complete the communication module of the vehicle network.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U495
【参考文献】
相关期刊论文 前1条
1 苏白龙;夏玮玮;沈连丰;;一种基于OFDMA的无线局域网MAC协议[J];蚌埠学院学报;2012年01期
，本文编号：2443443
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