《毕设论文——基于FPGA的数字下变频设计》.doc

毕业设计(论文)说明书 题 目： 院 （系）： 信息与通信学院 专 业： 信工程 学生姓名： 学 号： 指导教师： 职 称： 题目类型： 理论研究 实验研究 工程设计 工程技术研究 软件开发 20年 月 日 摘要 Abstract Digital Down Converter in the software radio for frequency and types of digital receivers have been widely used. It is an important part of software radio receiver. On the same time, Digital Down Converter is also the first work after A/D conversion. Its basic function is getting the required narrow-band signals from the inputting broadband digital signal. To down conversion to digital baseband signal, down to a suitable digital signal processor(DSP) processing speed, which has the largest operator and is the most difficult part to a digital processing system. Special DDC chips are expensive and flexibility is not strong, FPGA technology is developed rapidly, and spends less investment, can be repeated programming, relatively good performance security. Compared with ASIC and DSP, it has higher throughput, shorter development cycle and implements online re-structure and many advantages. On the basic of learning the knowledge of software radio and digital signal processing, I analysis the implementation method of FPGA-based Digital Down Converter. In this design, firstly determining the implementation scheme of the overall system, then dividing by function for each module, and then comparing and selecting various algorithms that have something with design process, finally finalize the implementation. The design is based on current popular quadrature mixing means to move IF signal to baseband signal spectrum, and then after the filtering of Muti-stage decimation filter, has the option of spectrum and ultimately lowers sampling rate. The Digital Down Converter applied FPGA design methods to complete the design and simulation of cic integral filter, hb half-band filter, fir and other related low-pass