基于FPGA的OFDM基带系统分析与设计

发布时间：2018-05-06 15:01

本文选题：无线通信 + 正交频分复用　；参考：《西安电子科技大学》2014年硕士论文

【摘要】：正交频分复用(OFDM,Orthogonal Frequency Division Multiplexing)是一种多载波调制和复用技术,具有抗多径效应与频率选择性衰落,符号与载波间干扰较小和频谱利用率较高等优点。在用户对无线数据传输速度要求越来越快和无线频率资源日益匮乏现状下,OFDM技术特别适合满足无线通信的高速化、宽带化、移动化的需求。随着OFDM理论的渐臻完善和相关实现技术的日益成熟,欧洲数字广播与电视、无线局域网和宽带无线接入等领域都推出了相关的物理层标准,已经商用的4G多数标准中物理层也都采用了OFDM相关技术,OFDM已经成为无线通信系统中物理层核心技术。首先本文简单的介绍了OFDM技术的基本原理与系统架构,以及相关的OFDM技术应用的物理层协议,并对OFDM符号波形和频谱进行MATLAB仿真。重点讨论了IEEE802.11a物理层标准,详细讨论了各个模块实现的技术原理和实现方法。其次分模块给出了系统的详细设计过程。其中在发射端:利用伪随机序列设计加扰模块,编码模块采用码率为1/2的卷积编码,利用分组算法实现交织器模块,在映射模块采用QPSK映射方式,实现了IFFT处理模块和循环前缀插入模块;接收端主要包括去循环前缀模块、FFT处理模块、QPSK解映射模块、解交织模块、Viterbi译码模块和去扰模块。为了保证系统能够对数据进行不间断流水线处理,我们设计了乒乓操作结构。其中系统的各个模块的相关操作和时钟控制则分别由两端的主控模块完成。最后我们进行了子模块及系统的功能性仿真和测试。通过测试验证了方案的可行性和正确性。
[Abstract]:Orthogonal Frequency Division Multiplexing) is a kind of multicarrier modulation and multiplexing technology, which has the advantages of anti-multipath effect and frequency selective fading, small symbol and carrier interference and high spectral efficiency. OFDM technology is especially suitable to meet the requirements of high speed, broadband and mobility of wireless communication under the condition that users need more and more fast wireless data transmission speed and increasingly lack of wireless frequency resources. With the improvement of OFDM theory and the maturity of related technologies, European digital broadcasting and television, wireless local area network and broadband wireless access have all introduced related physical layer standards. The physical layer of most of the 4G standards that have been commercialized has also adopted the OFDM related technology. OFDM has become the core technology of the physical layer in wireless communication systems. Firstly, this paper introduces the basic principle and system architecture of OFDM technology, and the physical layer protocol of OFDM application, and simulates the OFDM symbol waveform and spectrum by MATLAB. The IEEE802.11a physical layer standard is discussed in detail, and the technical principle and implementation method of each module are discussed in detail. Secondly, the detailed design process of the system is given. In the transmitter, the scrambling module is designed by using pseudorandom sequence. The coding module uses convolution coding with a bit rate of 1 / 2, implements the interleaver module with block algorithm, and adopts QPSK mapping mode in the mapping module. The IFFT processing module and the cyclic prefix insertion module are implemented, and the receiver mainly includes the decyclic prefix module, the deinterleaving module, the deinterleaving module and the descrambling module. In order to ensure that the system can process the data continuously, we designed the ping-pong operation structure. The related operation and clock control of each module of the system are completed by the main control module at both ends. Finally, we carry on the functional simulation and test of the sub-module and the system. The feasibility and correctness of the scheme are verified by test.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.53

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