OFDM基带和中频信号处理系统研究与实现

发布时间：2018-03-03 11:13

本文选题：OFDM　切入点：数字中频　出处：《电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,正交频分复用(OFDM)技术作为一种频谱利用率高和抗多径干扰能力强的高速传输技术,越来越得到人们的关注,现已成为4G无线通信系统中的核心关键技术。随着软件无线电技术的发展及软件无线电技术的灵活性和开放性,通信系统采用全数字化实现成为趋势。因此,结合上述两个背景,OFDM基带和中频系统的数字化实现十分具有研究意义。本文概括介绍了OFDM发展历史和优缺点以及OFDM系统的基本原理和关键技术,研究了IEEE802.11a物理层协议,在此基础上确定了OFDM基带和中频信号处理系统的实现方案。重点介绍了OFDM基带发射端、数字上变频、DAC、ADC、数字下变频、OFDM基带接收端中各个模块的原理和硬件实现方法,采用Verilog语言进行硬件编程,完成了基于FPGA的OFDM基带和中频信号处理系统的实现,并通过chipscope对系统中的每个模块进行了仿真测试。由于接收端的算法优劣对系统性能影响很大,针对OFDM基带接收端,本文将发射端的数据符号导出到MATLAB中进行信道模拟,对接收端进行了大量的测试,测试结果表明接收端能克服一定范围的信号噪声、频偏和简单的多径干扰。选择Xilinx公司的Virtex6和TI公司的DAC3152、ADS4229作为硬件平台,在硬件平台上完成了整个系统的联调。针对系统的特点,提出了特定的测试方案,完成了OFDM基带和中频系统的单板和双板测试。在单板和双板测试平台下,解码后的数据符号与原始数据符号完全相同,验证了该系统具备正确的功能和一定的性能,且该硬件平台能作为OFDM系统的信号处理平台。
[Abstract]:In recent years, orthogonal frequency division multiplexing (OFDM) technology as a spectrum technology of high-speed transmission rate and strong ability of anti multipath interference, more and more attention. It has become the key technology in 4G wireless communication system. With the development of software radio technology and software radio technology, flexibility and openness. The communication system adopts full digital realization become a trend. Therefore, the combination of the above two backgrounds, very meaningful for studying digital realization of OFDM baseband and intermediate frequency system. This paper summarizes the basic principle and key technologies of OFDM development history and the advantages and disadvantages of OFDM system, the research of IEEE802.11a physical layer protocol, based on the scheme OFDM baseband and intermediate frequency signal processing system. Introduced the OFDM baseband transmitter, digital frequency conversion, DAC, ADC, DDC, OFDM baseband receiver The principle and realization method of each hardware module, using Verilog language programming, implements FPGA OFDM baseband and intermediate frequency signal processing system based on chipscope, and through the simulation test of each module in the system. The receiver algorithm has a great impact on the performance of the system, according to the OFDM baseband receiver in this paper. The transmitted data symbols derived end through MATLAB channel simulation, the receiving end of a large number of tests, test results show that the noise signal receiver can overcome certain scope, frequency offset and simple multipath interference. The selection of Xilinx Virtex6 and TI, DAC3152, ADS4229 as the hardware platform in the hardware platform. Complete the adjustment of the whole system. According to the characteristic of the system, put forward the specific test plan, complete the board of OFDM baseband and intermediate frequency system and double plate test. In the single plate Under the dual board test platform, the decode data symbols are exactly the same as the original data symbols, which verify that the system has the correct function and certain performance, and the hardware platform can be used as the signal processing platform of OFDM system.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN929.53;TN911.7

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