软件无线电中采样率转换毕业设计西南科技大学本科生毕业论文 I软件无线电中采样率转换的FPGA实现摘要:随着软件无线电的不断发展，采样率转换技术成为了软件无线电硬件平台的关键技术。

利用该技术处理不同标准和速率的信号，使其能够在同一个硬件平台上实现不同速率的信号传输。

合理的设计和实现采样率转换系统，是目前软件无线电领域研究的重点和难点。

详细阐述了软件无线电中采样率转换系统的理论知识，提出了基于FPGA的本文采样率转换的整体设计方案，对两大核心模块:测试源模块和多速率处理模块进行了详细的设计。

在本方案中，测试源模块采用直接数字频率合成(DDS)技术，以ISE软件为平台，设计一个频率为2MHz、采样率为160MHz的正弦波。

多速率处理模块利用Matlab和ISE软件，完成了多速率处理模块中CIC抽取滤波器和HB抽取滤波器的详细设计，并对各个滤波器的功能进行仿真。

最后在Matlab和ISE软件中分别测试信号进行8倍的抽取，对总体方案进行simulink仿真和ModelSim仿真，实现对输出采样率为20MHz、频率仍是2MHz的无失真正弦波。

文末给出了设计过程中遇到的问题以及对问题的分析处理结果。

关键词: 采样率转换;DDS技术;CIC滤波器;HB滤波器;FPGA;西南科技大学本科生毕业论文 IISample Rate Conversion Implemented with FPGAin Software RadioAbstract: With the development of software radio, sample rate conversiontechnique plays a significant role in the hardware platform of software radio. Using this technology to deal with signal of different standards and rates can achieve signal sample rate conversion and signal transmission on the same hardware platform .Calculating and implementing a sample rate conversion system reasonably is important and difficultfor designer in the field of Software radio.Expounding the basic theory of sampling rate conversion of software radio system, this paper proposes the overall design scheme of sample rate conversion which is based onFPGA ,and the test source signal module and multi- rate processing module are discussed in detailIn this design, the test source signal ,a sine wave with frequency of 2MHz and sample rate of 160MHz, is designed in ISE software, adopting direct digital synthesis (DDS) technology. In multi-rate processing module, the CIC decimation filter and HB decimation filter are designed in detail, whose functions are emulated in ISE and Matlab software. Finally, output signal is converted into a undistorted sine wave with frequency of 2MHz and sample rate of 20MHz via the simulink emulation and ModelSim emulation which are completed in ISE and Matlab software. At the end of the thesis, it discusses the analysis and solution results to the problems, which are emerged in the design.Key words: Sample Rate Conversion, DDS technique, CIC filter; HB filter ,Field Programmable Gate Array(FPGA)西南科技大学本科生毕业论文 III目录第1章绪论 ..................................................................... (1)1.1选题的背景及目的意义 ..................................................................... .. (1)1.1.1课题研究背景 ..................................................................... (1)1.1.2 课题研究的目的及意义 ..................................................................... .. (1)1.2 多速率信号处理和实现方法 ..................................................................... (2)1.2.1多速率信号处理 ..................................................................... .. (2)1.2.2多速率信号处理实现方法 ..................................................................... ..21.3 设计指标和关键技术 ..................................................................... .. (3)1.4 本文主要内容 ..................................................................... .............................3 第2章方案论证 ..................................................................... (4)2.1 系统设计思想 ..................................................................... .. (4)2.2 系统方案论证 ..................................................................... .. (4)2.2.1 正弦波发生器模块...................................................................... (4)2.2.2 多速率处理模块 ..................................................................... ................5 第3章系统设计相关原理 ..................................................................... (6)3.1 信号抽取原理 ..................................................................... .. (6)3.2 高效滤波器 ..................................................................... (7)3.2.1 CIC滤波器 ..................................................................... . (7)3.2.1.1 单级CIC .................................................................... .. (8)3.2.1.2 多级CIC .................................................................... (10)3.2.2 HB滤波器 ..................................................................... (12)3.2.3 FIR滤波器 ..................................................................... (14)3.2.3.1 FIR滤波器原理 ..................................................................... . (14)3.2.3.2 FIR的FPGA实现结构 .............................................................. 15 3.3 直接数字合成(DDS)技术 ..................................................................... ........ 16 第4章系统总体设计和核心模块设计 ...................................................................184.1 多速率系统方案总体设计 ..................................................................... .. (18)4.1.1 多速率系统总结构...................................................................... . (18)西南科技大学本科生毕业论文 IV4.1.2参数计算 ..................................................................... (18)4.2 核心模块设计 ..................................................................... (19)4.2.1 DDS模块设计 ..................................................................... (19)4.2.2 CIC滤波器设计 ..................................................................... . (21)4.2.2.1 积分模块 ..................................................................... (21)4.2.2.2 抽取模块 ..................................................................... (22)4.2.2.3 梳状模块 ..................................................................... (23)4.2.2.4 CIC参数计算 ..................................................................... .. (23)4.2.3 HB滤波器设计 ..................................................................... .. (25)第5章系统 FPGA 硬件代码设计和仿真 (29)5.1测试源文件 ..................................................................... .. (29)5.2 CIC抽取滤波器仿真 ..................................................................... .. (29)5.3 HB抽取滤波器仿真 ..................................................................... (32)5.4多速率系统仿真 ..................................................................... (34)结论 ..................................................................... ..................................................... 37致谢 ..................................................................... ..................................................... 38 参考文献...................................................................... ................................................ 39 附录1:FPGA设计顶层原理图 ..................................................................... ............ 41 附录2:DDS 测试源Verilog HDL代码 ....................................................................42 附录3: CIC抽取滤波器Verilog HDL代码 (44)附录4: HB抽取滤波器Verilog HDL代码 (48)附录5: MATLAB 产生ROM程序 ..................................................................... ........... 55 附录6: CIC 抽取滤波器M文件 ..................................................................... .. (56)西南科技大学本科生毕业论文第1章绪论1.1选题的背景及目的意义1.1.1课题研究背景软件无线电是一种新型无线通信技术，其中心思想是:构造一个具有开放性、标准化、模块化的通用硬件平台，将各种功能，如工作频段、数据格式、调制解调类型、加密模式、通信协议等用软件来完成，并使宽带A/D和D/A转换器尽可能地靠近天线，[1]以研制出具有高度灵活性和开放性的新一代无线通信系统。