基于双速率欠采样的宽带数字信道化接收机设计及其FPGA实现

发布时间：2018-01-26 21:32

本文关键词： 欠采样宽带接收机数字信道化短时傅里叶变换　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：宽带数字信道化接收机作为电子侦察的重要组成部分,在电子战运用中起到关键作用。面对复杂的电子战电磁环境,研究瞬时频带更宽、动态范围更大、灵敏度更高、以及多个信号同时处理和实时处理能力更强的数字信道化接收机一直是电子侦察领域的重要课题。传统宽带数字接收机一般针对零中频信号进行处理,但数字下变频I、Q两路会存在幅相不平衡问题,这将导致镜像分量出现难以区分出真实信号,同时镜像分量的存在不利于微弱信号的检测,从而限制了数字接收机的动态范围。随着高速ADC采样技术的快速发展,直接对射频信号进行采样和处理已成为现实并逐步开始应用。本文将射频信号采样与处理结合数字信道化技术,设计了基于双速率欠采样的宽带数字信道化接收机。在高速ADC与FPGA的硬件平台基础上,实现了基于短时傅里叶变换(STFT)结构的信道化接收机,完成对射频宽带信号的检测与处理。本文主要工作如下:1、介绍宽带数字接收机的研究背景与研究现状,从采样定理、多速率信号处理、数字滤波器组等理论阐述数字信道化结构,并结合欠采样技术设计宽带数字信道化接收机。2、论述基于短时傅里叶变换方法构建的频域数字信道化结构,提出结合双速率欠采样的频域数字信道化接收机,通过MATLAB对常见雷达体制信号进行数字信道化仿真,验证了该结构的可行性。3、在数字信道化接收机理论基础上,构建了以射频ADC与FPGA相结合的硬件平台,设计了FPGA实现信道化接收机各功能程序,利用Modelsim仿真验证了其功能,并分析了其性能,最后通过工程实测数据验证了其有效性。
[Abstract]:As an important part of electronic reconnaissance, wideband digital channelized receiver plays a key role in the application of electronic warfare. More sensitive. Digital channelized receiver which can process multiple signals simultaneously and in real time has been an important subject in the field of electronic reconnaissance. Traditional wideband digital receiver usually processes zero if signal. However, the amplitude and phase imbalance problem will exist in the two channels of digital downconversion, which will make it difficult to distinguish the real signal from the image component, and the existence of the image component is not conducive to the detection of weak signal. This limits the dynamic range of digital receiver. With the rapid development of high-speed ADC sampling technology. Direct sampling and processing of RF signal has become a reality and gradually began to be applied. This paper combines RF signal sampling and processing with digital channelization technology. A wideband digital channelized receiver based on double rate under-sampling is designed based on the hardware platform of high-speed ADC and FPGA. A channelized receiver based on STFT structure is implemented to detect and process RF wideband signals. The main work of this paper is as follows: 1. This paper introduces the research background and present situation of wideband digital receiver, and expounds the digital channelization structure from sampling theorem, multi-rate signal processing, digital filter bank and so on. The wideband digital channelized receiver. 2 is designed based on the under-sampling technique. The frequency domain digital channelization structure based on the short time Fourier transform (STFT) method is discussed. A frequency domain digital channelized receiver based on dual rate under-sampling is proposed. The simulation of digital channelization of common radar system signals by MATLAB is carried out, and the feasibility of this structure is verified. 3. Based on the theory of digital channelized receiver, a hardware platform based on RF ADC and FPGA is constructed, and FPGA is designed to realize each function program of channelized receiver. Its function is verified by Modelsim simulation, and its performance is analyzed. Finally, the validity of the proposed method is verified by practical engineering data.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN850

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