LTE-A系统下行链路MIMO检测的研究与实现

发布时间：2018-01-13 14:21

本文关键词：LTE-A系统下行链路MIMO检测的研究与实现　出处：《电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：MIMO-OFDM技术广泛应用于现代无线通信系统中,本文主要研究了应用于LTE/LTE-A系统下行物理层的MIMO检测相关算法与FPGA实现。本文首先介绍了移动通信发展历程和LTE/LTE-A系统技术背景概况,阐述了LTE/LTE-A系统中MIMO检测的研究意义和现状。接着介绍了LTE-A系统下行物理层的一些基本原理和关键技术,包括下行物理层FDD帧格式和资源映射原理,调制原理与软信息解调算法,小区专用参考信号的产生原理和映射规则,OFDM技术原理,MIMO技术中的层映射和预编码,以及扩展IUT信道模型等。然后基于应用于LTE-A系统的MIMO-OFDM系统和多径衰落模型,研究了MIMO检测相关算法。分别对MIMO检测中的导频信道估计算法、数据信道插值算法和信号检测算法展开研究。导频信道估计研究了LS估计算法、MMSE估计算法和LMMSE估计算法;数据信道插值研究了常值插值算法、线性插值算法和拉格朗日插值算法;信号检测研究了ML检测算法、ZF检测算法、MMSE检测算法、OSIC检测算法和SD检测算法。基于Matlab搭建了LTE-A下行物理层MIMO检测仿真链路平台,在EPA信道模型和EVA信道模型中QPSK、16QAM和64QAM三种调制模式下,分别地对三种信道估计算法、三种信道插值算法和五种信号检测算法进行了仿真对比和性能分析。从性能和实现复杂度折中考虑,最后以LS估计算法、线性插值算法和ZF检测算法作为LTE-A下行物理层MIMO检测的实现算法,设计了MIMO检测的硬件实现架构方案。对MIMO检测的本地参考信号生成、LS估计、线性插值和ZF均衡等四个子模块的硬件实现结构分别进行了详细阐述。基于Xilinx公司的高性能Kintex-7系列FPGA芯片XC7K325T对MIMO检测模块进行了硬件实现,并且通过Modelsim的功能仿真定点运算结果与Matlab仿真浮点运算结果对比验证了实现的正确性。MIMO检测模块经过综合后资源使用控制在20%以内,最大运行频率273.148MHz。在20MHz系统带宽配置和245.76MHz系统时钟条件下,64QAM调制的吞吐率达到100.91Mbps,性能分析结果表明本文实现的MIMO检测模块能够满足项目需求。
[Abstract]:MIMO-OFDM technology is widely used in modern wireless communication systems. This paper mainly studies the related algorithms and FPGA implementation of MIMO detection applied to the downlink physical layer of LTE/LTE-A system. Firstly, this paper introduces the development history of mobile communication and LTE/LTE-A. Background of system technology. In this paper, the significance and present situation of MIMO detection in LTE/LTE-A system are described. Then, some basic principles and key technologies of downlink physical layer of LTE-A system are introduced. It includes downlink physical layer FDD frame format and resource mapping principle, modulation principle and soft information demodulation algorithm, cell specific reference signal generation principle and mapping rule. Layer mapping and precoding in MIMO technology, and extended IUT channel model, etc. Then based on MIMO-OFDM system and multipath fading model applied to LTE-A system. The related algorithms of MIMO detection are studied. Pilot channel estimation algorithm, data channel interpolation algorithm and signal detection algorithm in MIMO detection are studied respectively. LS estimation algorithm is studied in pilot channel estimation. MMSE estimation algorithm and LMMSE estimation algorithm; Data channel interpolation includes constant interpolation algorithm, linear interpolation algorithm and Lagrange interpolation algorithm. The ML detection algorithm, ZF detection algorithm and MMSE detection algorithm are studied in signal detection. OSIC detection algorithm and SD detection algorithm. Based on Matlab, the LTE-A downlink MIMO detection simulation link platform is built. In the EPA channel model and the EVA channel model, three channel estimation algorithms are proposed under the three modulation modes of QPSKKP16QAM and 64QAM. Three channel interpolation algorithms and five signal detection algorithms are compared and analyzed. Considering the performance and implementation complexity, the LS estimation algorithm is used. Linear interpolation algorithm and ZF detection algorithm are used as LTE-A downlink physical layer MIMO detection algorithm. The hardware architecture of MIMO detection is designed, and the LS estimation of the local reference signal of MIMO detection is presented. The hardware implementation structure of four sub-modules, linear interpolation and ZF equalization, are described in detail. High performance Kintex-7 Series FPGA Chip XC7K325T based on Xilinx Company. The hardware of the MIMO detection module is implemented. The simulation results of fixed point and floating-point operation of Modelsim are compared with those of Matlab, and the correctness of the implementation is verified. Within 20%. The maximum operating frequency is 273.148MHz. Under 20MHz system bandwidth configuration and 245.76MHz system clock condition. The throughput of 64QAM modulation is 100.91Mbpss. the performance analysis results show that the MIMO detection module can meet the requirements of the project.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

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