1、 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。 本文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 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
2、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 对总体方案进行 simulink 仿真和 ModelSim 仿真，实现对测试信号进行 8 倍的抽取， 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； Sample Rate Conversion Implemented with FPGA in
3、 Software Radio Abstract: With the development of software radio, sample rate conversion technique 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 tran
4、smission on the same hardware platform .Calculating and implementing a sample rate conversion system reasonably is important and difficult for designer in the field of Software radio. Expounding the basic theory of sampling rate conversion of software radio system, this paper proposes the overall de
5、sign scheme of sample rate conversion which is based on FPGA ,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
6、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 problem
