【作者】 熊邦龙；

【导师】 朱新宁；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2013， 硕士

【摘要】 通用移动通信系统(Universal Mobile Telecommunications System, UMTS)的长期演进(Long Term Evolution,LTE)项目正在经历研发和产业化进程。作为其中的重要组成部分,时分双工系统下的TD-LTE的相关技术研究也备受关注。本文针对TD-LTE-A载波聚合场景下的终端发射机射频特性进行了深入的研究。首先对载波聚合技术及射频系统的非线性特性进行了简要介绍,总结了载波聚合场景下的终端射频特性指标；其次针对终端发射机的射频指标,搭建仿真测试平台并进行了频谱辐射模板(Spectrum Emission Mask, SEM),邻信道泄漏比(Adjacent Channel Leakage power Ratio, ACLR)和带内辐射(In-band emissions)等测试例的仿真分析。仿真过程中,本文重点研究射频功率放大器的非线性对终端上行发射信号射频特性的影响。最后,针对载波聚合技术易导致终端上行信号峰值平均功率比急剧增大的问题,本文分析研究了一种常用的线性化技术,即“终端最大功率回退”机制,并通过仿真测试得出终端射频因素和信号自身特性对最大功率回退的影响。本文的仿真测试结果和研究结论既能指导TD-LTE-A终端的射频设计,也为终端射频一致性测试标准的修订提供一定的依据。更多还原

【Abstract】 The Long Term Evolution (LTE) Project of Universal Mobile Tele-communications System (UMTS) is during the process of researching and industrialization. As an important part of the process, TD-LTE system which uses the technology of Time Division Duplex (TDD) also received much concern.This paper focused on the Radio Frequency (RF) characteristics of User Equipment (UE) transmitter for Carrier Aggregation (CA) in TD-LTE-A system and conducted thorough research on them. Firstly, the CA technique and the nonlinear characteristics of RF system were briefly introduced, meanwhile, the RF requirements of UE in CA scenarios were summarized. In addition, a simulating platform was established according to the RF requirements of UE transmitter and test cases such as Spectrum emission mask (SEM), Adjacent Channel Leakage Ratio (ACLR) and In-band emissions were simulated and analyzed. During the process of simulation, the nonlinearity of RF Power Amplifier (PA) was specially analyzed in this paper since it had great influence on the characteristics of Uplink transmitting signal. Lastly, facing to the fact that CA technique drove the Peak to Average Power Ratio (PAPR) of Uplink transmitting signal to the extreme level, this paper studied a common linearization technique called Maximum Power Reduction (MPR) of UE. Furthermore, this paper discovered that both the RF factors of UE and the characteris-tics of signal itself that had great impact on the value of MPR.The simulation results and research conclusions in this paper can not only guide the RF design of UE in TD-LTE-A system, but also provide valuable references to the modification of standards of UE RF conform-ance testing.更多还原