【正文】 sisting of eNodeBs is used in LTE work, so the work structure is flat. There are many new technologies are introduced to the physical layer of LTE air interface, including OFDM, multiantenna technology and TDD/FDD frame structure. OFDM is an orthogonal multicarrier technology, and its carrier interval is 15KHz in LTE system, symbol rate being 15KS/s as mentioned in the previous literatures. However there is no detail about the relationship between the two in those literatures. The relationship for them is discussed in this article. Furthermore, the performances of LTE TDD/FDD physical layers based on the frame structures are discussed in this article. As the carrying capacity of the physical layer determined by the above mentioned technologies, the utilization of this capacity is to a large extent determined by the MAC layer packet scheduling algorithm. Several traditional and modified PF algorithms based on the singleservice scenario are introduced in this article, and a new LSMPF algorithm is proposed to achieve higher system throughput. Moreover a number of QoSaware algorithms are discussed in this article. The performances of these algorithms are not satisfactory in LTE multiservice scenario. Therefore, two new algorithms, Ag1 and Ag2 are proposed. Ag1 and Ag2 algorithms are based on MLWDF algorithm and meet the minimum bit rate requirement of different user’s service by restricting and pensating the number of RBs to different user respectively. A method of logically updating the first packet delay of a service queue is added in the Ag2 algorithm. It helps to keep the balance of the length of the waiting queues, which is necessary for a better meet of the packet delay requirements. So the Ag2 algorithm achieves a higher system throughput. At last all the algorithms discussed in this article are analyzed in a MATLAB simulation platform. Keywords: OFDM, Orthogonal Multicarrier, Multiantenna, Frame Structure, Scheduling Algorithm 南京郵電大學(xué)碩士研究生學(xué)位論文 目錄 III 目錄 第一章 緒論 ........................................................................................................................................ 1 移動通信系統(tǒng)的發(fā)展 ............................................................................................................. 1 LTE 項(xiàng)目的需求及標(biāo)準(zhǔn)概述 ................................................................................................. 2 TD LTE 標(biāo)準(zhǔn) ......................................................................................................................... 5 本論文的工作及安排 ............................................................................................................. 6 第二章 LTE 系統(tǒng)結(jié)構(gòu)及空中接口 ................................................................................................... 7 EUTRAN 架構(gòu) ...................................................................................................................... 7 EPS 網(wǎng)絡(luò)結(jié)構(gòu) ............................................................................................................... 7 S1 和 X2 接口 ............................................................................................................... 7 網(wǎng)元的功能 ............................................................................................................................ 8 MME/GW ..................................................................................................................... 8 eNode B ....................................................................................................................... 10 EUTRAN 空中接口 ............................................................................................................ 10 空中接口分層結(jié)構(gòu) .................................................................................................... 10 各層功能 .................................................................................................................... 11 本章小結(jié) ............................................................................................................................... 12 第三章 LTE 物理層關(guān)鍵技術(shù) ......................................................................................................... 13 OFDM 多址接入技術(shù) .......................................................................................................... 13 OFDM 技術(shù)原理 ........................................................................................................ 13 LTE 下行 OFDMA 技術(shù) ............................................................................................ 15 LTE 上行 DFTSOFDM 技術(shù) ................................................................................... 17 正交載波間隔與碼元速率 ......................................................................................... 19 多天線技術(shù) .......................................................................................................................... 22 波束賦形智能天線 ..................................................................................................... 23 MIMO 技術(shù) ................................................................................................................ 23 無線幀結(jié)構(gòu) .......................................................................................................................... 30 LTEFDD 幀結(jié)構(gòu) ........................................................................................................ 30 LTETDD 幀結(jié)構(gòu) ....................................................................................................... 30 基于幀結(jié)構(gòu)的性能估算 ............................................................................................. 31 本章小結(jié) ............................................................................................................................... 33 第四章 LTE 中的 MAC 層分組調(diào)度技術(shù) .......................