任意波形发生模块数字通道的设计与实现

发布时间：2019-01-11 13:52

【摘要】：任意波形发生器是一种特殊的信号源,其具有信号源的所有特点。在当今通信测试系统中,单通道任意波形发生器已不能满足对测试精度和测试参数范围的要求。为了满足随着科技的发展和对测试系统精度的要求,需要双通道甚至多通道的激励信号,并设计出能够提供多制式、高精度的任意波形发生器。本文是依据便携式矢量信号源项目为研究背景,重点研究了在任意波模式下的基带波形产生技术和多速率任意波形信号的变采样率处理技术。本文是基于软件无线电的思想,以“DSP+FPGA+DDR3+DA板”为硬件平台,通过方案设计、测试仿真及验证,实现了基带信号可达800MSa/s的存储速率和最高200倍插值倍数的信号重建。本文首先介绍了本课题设计的总体方案,其主要包括变速率基带信号处理与数字任意波形信号的数模转换两个内容。变速率基带信号处理主要包括以下三个模块:一、FPGA接收DSP传输命令和数据通道的设计,完成了DSP和FPGA之间的信号通讯。二、DDR3 SDRAM数据存储模块的设计,通过对DDR3 SDRAM存储控制器的配置、仿真及验证,保证数字基带信号高速写入与读取操作,实现了数字基带信号的回放功能。三、变采样率处理模块的设计,通过FIR+CIC组合滤波器的设计,可以高效地滤除任意波形的镜像成分并抑制其谐波分量,从而获得平滑、完整的任意波形信号。数字任意波形的数模转换模块是本文的另个一重要方面,从FPGA处理后的任意波形信号转换为模拟任意波形信号需要通过高速数模转换,将产生的模拟任意波形信号上变频到任意波形发生器的射频模块并通过相应的信号调理电路实现波形的输出。本文提供了一套任意波形发生模块数字通路的设计技术,其中一部分模块是在Airtx-7系列FPGA中实现的,另一部分是在D/A板上实现的,并利用频谱分析仪和ChipScope软件等测试工具对各个功能模块进行了验证,实现了双通道任意波形的产生,满足预定数字通路的要求。
[Abstract]:Arbitrary waveform generator is a special signal source, which has all the characteristics of signal source. In today's communication test system, the single channel arbitrary waveform generator can not meet the requirements of test accuracy and test parameter range. With the development of science and technology and the requirement of the precision of the test system, the excitation signal of two channels or even multiple channels is needed, and an arbitrary waveform generator with multi-standard and high precision is designed. Based on the research background of portable vector signal source, this paper focuses on the baseband waveform generation technology in arbitrary wave mode and the variable sampling rate processing technology of multi-rate arbitrary waveform signal. This paper is based on the idea of software radio, taking "DSP FPGA DDR3 DA board" as hardware platform, through scheme design, test, simulation and verification, the storage rate of baseband signal can reach 800MSa/s and the signal reconstruction of maximum 200 times interpolation multiple is realized. This paper first introduces the overall scheme of this project, which mainly includes two parts: variable rate baseband signal processing and digital-analog conversion of digital arbitrary waveform signal. Variable rate baseband signal processing mainly includes the following three modules: first, the FPGA receives the DSP transmission command and the design of the data channel, completes the signal communication between DSP and FPGA. Secondly, the design of DDR3 SDRAM data storage module, through the configuration, simulation and verification of the DDR3 SDRAM storage controller, ensures the high-speed writing and reading operation of the digital baseband signal, and realizes the playback function of the digital baseband signal. Thirdly, the design of variable sampling rate processing module, through the design of FIR CIC combined filter, can efficiently filter the mirror image component of arbitrary waveform and suppress its harmonic component, so as to obtain smooth and complete arbitrary waveform signal. The digital-analog conversion module of digital arbitrary waveform is another important aspect of this paper. The conversion from arbitrary waveform signal processed by FPGA to analogue arbitrary waveform signal needs high-speed digital-to-analog conversion. The generated analog arbitrary waveform signal is up-converted to the RF module of the arbitrary waveform generator and the waveform output is realized by the corresponding signal conditioning circuit. This paper provides a set of digital path design techniques for arbitrary waveform generation module, some of which are implemented in Airtx-7 series FPGA, the other part is implemented on the D / A board. The function modules are verified by using spectrum analyzer and ChipScope software, which can realize the generation of arbitrary waveforms of two channels and meet the requirements of predetermined digital paths.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN702

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