基于TDD-LTE的高速铁路无线宽带通信研究

发布时间：2019-07-06 10:22

【摘要】：在移动互联网时代的今天,用户对通信技术的各方面要求越来越高。长期演进计划((long term evolution,LTE)作为拥有高传输速率、高传输质量和移动性能的通信手段,成为了移动通信系统中倍受关注的研究热点。随着高速铁路的发展,其对在高移动速度下的通信要求更为苛刻。然而,LTE系统下行的正交频分多址(orthogonal frequency division multiplexing access,OFDMA)技术与上行的单频载波多址(single-carrier frequency-division multiple access,SC-FDMA)技术在高速度移动环境下对频率偏差表现得更为敏感,多普勒频移也更加明显。这使得LTE面临着巨大的挑战。本文从TDD-LTE的多普勒频移对抗入手,重点研究TDD-LTE系统在高速铁路环境下的相关技术。首先,对LTE系统的构架、接口、物理层及核心技术OFDM进行概述,同时对通信信道以及高铁通信的特殊环境及信道进行介绍,并对LTE上行、下行相关理论进行初步讨论。然后,重点研究下行链路在小区终端射频单元(Radio Remote Unit,RRU)切换时产生的多普勒突跳,以及上行链路在多个用户条件下的子载波干扰与用户间干扰。进而,针对TDD-LTE系统提出了有效解决下行多普勒突跳的方案及算法。同时,研究并比较了多种上行链路抗用户间干扰算法,给出了接近没有用户间干扰的理想解决办法。最后,利用本文算法在京津高铁案例TD-LTE覆盖区专线试验区与非试验区进行实验,并根据对比数据得出结论,以此说明本文讨论的相关优化算法以及解决方案在实际应用中的意义。
[Abstract]:In the era of mobile Internet, users have higher and higher requirements for all aspects of communication technology. Long-term evolution plan (long term evolution,LTE), as a means of communication with high transmission rate, high transmission quality and mobile performance, has become a hot research topic in mobile communication systems. With the development of high-speed railway, the communication requirements at high mobile speed are more stringent. However, the orthogonal frequency division multiple access (orthogonal frequency division multiplexing access,OFDMA) technology and uplink single frequency carrier multiple access (single-carrier frequency-division multiple access,SC-FDMA) technology in LTE system are more sensitive to frequency deviation and Doppler shift in high speed mobile environment. This makes LTE face great challenges. Starting with the Doppler shift confrontation of TDD-LTE, this paper focuses on the related technologies of TDD-LTE system in high-speed railway environment. Firstly, the architecture, interface, physical layer and core technology OFDM of LTE system are summarized. At the same time, the communication channel and the special environment and channel of high-speed rail communication are introduced, and the related theories of uplink and downlink of LTE are discussed. Then, the Doppler jump caused by downlink switching of cell terminal radio frequency unit (Radio Remote Unit,RRU), as well as the subcarrier interference and inter-user interference of uplink under multiple user conditions are studied. Furthermore, an effective scheme and algorithm to solve the downlink Doppler jump for TDD-LTE system is proposed. At the same time, a variety of uplink anti-inter-user interference algorithms are studied and compared, and an ideal solution is given, which is close to no inter-user interference. Finally, the algorithm is used to carry out experiments in the special line test area and non-test area of TD-LTE coverage area of Beijing-Tianjin high-speed railway case, and the conclusion is drawn according to the comparative data, so as to illustrate the significance of the relevant optimization algorithm discussed in this paper and the solution in practical application.
【学位授予单位】：燕山大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN929.5

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