【作者】 赵强；

【导师】 何春；

【作者基本信息】 电子科技大学 ， 通信与信息系统， 2013， 硕士

【摘要】 现代生活中，移动通信技术已经全方位的融入到了人们的日常生活。以LTE-A为代表的4G通信系统正不断的推动着整个无线通信领域的技术革新.随着多输入多输出（MIMO）技术、正交频分（OFDM）等一大批新兴技术的加入，4G技术规范逐渐变得成熟。本文首先简要介绍了LTE-A系统的相关技术背景和物理层的基本概念。然后针对LTE-A下行链路系统中小区搜索和MIMO检测进行了研究。LTE-A系统中，小区搜索采用二级同步的思想，通过主同步信号（PSS）和辅助同步信号（SSS）的检测来完成对小区信息的检测与获取。小区搜索过程是LTE-A系统基站与用户终端建立与保持通讯的前提，是接收端进行其他解调操作的基础，其性能的好坏直接影响到LTE-A系统的性能好坏，因此具有极其重要的研究意义。MIMO技术在不增加带宽和发射机发送功率的前提下，通过增加发射端发射天线和接收端接收天线的个数，能够成倍的提高系统信道的容量和质量，因此， MIMO检测技术也是当前的研究热点之一。针对小区搜索，本文主要完成了对小区搜索模块的matlab仿真、硬件结构设计和FPGA实现。首先，分模块搭建了小区搜索的matlab算法仿真平台，包括PSS信号的检测、SSS信号的检测、频偏估计以及CP检测等过程。本文针对CP检测模块利用滑动相关的思想改进了自相关CP检测算法，提高了CP的检测精度，同时改进了SSS序列检测的算法，减小了SSS检测的计算量。然后，根据项目要求设计并优化了小区搜索模块的硬件结构。本文使用CIC滤波器组的设计思想减少滤波器设计的资源消耗；针对PSS的结构特点，采用折叠的思想设计PSS检测器；采用滑动搜索的思想改进CP检测模块；采用多CP模式完成小数倍频偏的估计同时完成PSS精同步过程等。针对MIMO检测，本文主要完成了信道估计和信道均衡的matlab仿真，根据项目要求对设计了LS信道估计模块的ZF均衡模块的设计。最后，本文设计的所有小区搜索硬件模块和MIMO检测硬件模块都在xilinx公司K7系列芯片XC7K325T完成了硬件实现。更多还原

【Abstract】 Recently, mobile communication technology has been incorporated into people’sdaily life.4G communication system, such as LTE-A, is constantly driving the technicalinnovation in the entire field of wireless communication. With a large number ofemerging technologies joining in, especially multiple input multiple output (MIMO) andOrthogonal Frequency Division Multiplexing (OFDM),4G technical specification isgradually becoming mature.In this paper, Firstly the related technical background of the LTE-A system and thebasic concept of physical layer are briefly introduced. Then the paper focuses on thetwo directions of the cell search in the downlink and the MIMO detection. Cell searchuses the way of secondary synchronization to detect and obtain the detection of the cellinformation by detecting primary synchronization signal (PSS) and secondarysynchronization signal (SSS). The cell search process is an important guarantee of theLTE-A system to establish and maintain communications between the base station (BS)and user equipment (UE), and it’s also the basis of other’s demodulation operation.Synchronization performance directly affects the performance of the LTE-A system, sothe research into cell search process has an extremely important significance. Withoutincreasing transmitting power or transmission bandwidth, system channel’s throughputand quality can be exponentially improved by using MIMO to increase the number oftransmitting antenna and receiving antenna.Therefore，MIMO detection technology hasalso becoming one of researching hotspots currently.Matlab simulation, hardware architecture design and FPGA implementation havebeen done in cell search module. The algorithm simulation platform of the cell searchincluding PSS detection, SSS detection, the frequency offset estimation and CPdetection process, etc, has been builded with matlab firstly. An improved CP detectionalgorithm is proposed in this paper, which uses the method of sliding correlation toincrease the measuring accuracy of CP detection. While a SSS sequence detectionalgorithm is improved to reduce the amount of calculation of the SSS detection.Then,the paper designs and optimizes the hardware structure of Cell Search module according to the project requirements. In this article, Low-passed filter is replaced by CIC filterbank to reduce the resource consumption; the folding structural is used in PSS detection;CP detection module is improved by Sliding correlation; the decimal frequency offsetand PSS fine synchronous head are estimated together by multiple CP mode; etc. Thechannel estimation and equalization has been finished by using matlab platform forMIMO detection.Then the Pipeline structure of the LS channel estimation module andZF equalization module are designed on the basic of the project requirement.Finally, all of the hardware architectures are implemented on Xilinx’s Kintex-7series FPGA chip XC7K325T.更多还原