5G空口信号分析方案设计及仿真_毕业论文.pdf

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摘 要

第五代移动通信技术（5G）采用了全新的频谱方案和灵活的帧结构设计，极大地丰

富了移动终端时频资源分配机制，以一套高灵活的空口设计应对不同业务场景对时延、

带宽的需求。在安全机制方面，5G 鉴权认证采用非对称密钥密码体制，有效地解决了

前代通信系统存在的用户身份信息泄漏的问题。灵活的空口设计和严格的鉴权认证机制

使得空口信号分析方案复杂度大大增加，难以满足实际应用的需求。

论文以 RRC 层的信令交互为切入点，提出 5G 独立组网下被动式的空口信号分析原

由于被动式方案的特殊性，方案要求第三方无线电设备能够快速地完成下行同步以

保障研究任务的开展。根据 5G 同步信道与广播信道的新特性，论文从传统的 LTE 下行

同步算法出发，研究了 5G 下行同步算法。通过改进本地 PSS 序列、引入非相干积累提

升算法在低信噪比下的检测性能；利用联合粗频偏估计与残留频偏估计的新方案提升频

偏估计性能。在基于 Matlab 仿真软件建立的 5G 下行链路级仿真平台上，改进后的下行

同步算法在大频偏和低信噪比的 TDL-C 以及 AWGN 信道下都有着稳定的性能表现。

关键词

：空口信号分析，RRC，TMSI，下行同步

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resources allocation mechanism for mobile devices. Also a set of highly flexible air interface

design is used to meet the demand for delay and bandwidth in different service scenarios. In

terms of security mechanism, asymmetric key cipher system is adopted in 5G authentication

to effectively solve the problem of user identity information leakage as in previous

generations of communication system. This flexible air interface design and strict

authentication mechanism have increased the complexity of the air interface signal analysis

solution to meet the needs of practical applications.

Based on the signaling interaction at the RRC layer, this paper proposes a passive signal

analysis principle scheme in 5G NR under stand alone networking. The scheme takes

advantage of the lack of integrity protection of the paging channel to obtain the temporary

TMSI. Subsequent work can use the uplink signal analysis equipment to extract the uplink

reference signal of the target terminal, to provide support for the work of orientation,

positioning, etc.

Due to the particularity of the passive scheme, quick downlink synchronization by the

third party radio equipment is required to guarantee the research task. Based on the new

characteristics of 5G synchronous channel and broadcast channel, 5G downlink

synchronization algorithm is studied, starting from the traditional algorithm for LTE downlink

synchronization. To improve the detection performance of the algorithm at low

signal-to-noise ratio, the local PSS sequence is mended and non-coherent accumulation is

introduced. To improve the frequency bias estimation performance, a new scheme of joint

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目 录

摘 要 ..................................................................................................................................... I

Abstract .................................................................................................................................... III

目 录 ................................................................................................................................... V

插图目录 ................................................................................................................................. VII

表格目录 .................................................................................................................................. IX

通信缩略词 .............................................................................................................................. XI

第一章 绪论 ............................................................................................................................ 1

1.1 课题背景和研究意义 ............................................................................................... 1

2.2 5G 物理层帧结构 ................................................................................................... 11

2.3 5G 同步信号 ........................................................................................................... 14

2.4 5G 下行控制信道 ................................................................................................... 19

2.5 5G 常见信令过程 ................................................................................................... 22

3.4 目标终端 TMSI 捕获 ............................................................................................. 33

3.5 TMSI 与 C-RNTI 映射表建立 ............................................................................... 34