摘要在现代电子战中,随着电子侦查环境的复杂化,要求侦查接收机不仅要具有大的带宽,而且要对信号具有高截获概率和多信号处理的能力。得益于数模转换器(ADC)和数字信号处理器速度的提高,宽带数字接收机成为现代电子战系统的重要组成部分。
本文详细讨论了宽带数字接收机对同时多信号的测频技术,并对其测频结果进行了仿真分析;分析了几种测频处理方法的原理,对其进行仿真;讨论了欠采样数字测频的原理,对欠采样中的测频模糊问题提出解决方法并进行仿真分析;讨论信道化测频技术的原理及多相滤波器的设计,并其结构进行测频性能的仿真。59616
毕业论文关键词:数字信号处理 数字测频 宽带数字接收机 欠采样测频 信道化
毕业设计说明书(论文)外文摘要
Title High-speed broadband digital frequency Measurement techniques
Abstract
In the field of modern electronic war,the operational environment of EWRR(Electronic War Reconnaissance Receiver) is more and more complex In many radar countermeasure applications,it urgently demanded for characterestics of EWRR of wideband,high intercept probability and processing capability of simulataneous singales.Due to the speed improvement of digital-to-analog converter (ADC) and digital signal processor, wideband digital receivers became an important part of modern electronic warfare system.
In this paper,the frequency measurement technology of wideband digital receiver signals for simultaneous multi-signal is analyzed in detail,and the results of processing are simulated and analyzed.Then,the principles of several methods of frequency measurement are summed up.Afterward, the principle which describes sub-Nyquist sampling digital frequency measurement are discussed.And sulotions to the illegibility problem are put forward and proved to be correct.Finally,the method of digital channelized filters is discussed. A polyphase filter bank is designed and the scheme based on the filters is simulated to prove its performance.
keywords: Digital Signal Processing Digital frequency measurement Wideband digital receiver Sub-Nyquist sampling Channelized filters
1 绪论 1
1.1 研究背景 1
1.2 测频技术的发展及趋势 2
1.3 本文的工作 3
2 有噪信号的产生 4
2.1信号模型 4
2.2 噪声模型 5
2.3 本文仿真所用的信号模型 6
3 同时多信号测频技术 8
3.1 基于DFT算法的测频技术 8
3.2 功率谱估计 10
3.2.1 经典功率谱估计法 10
3.2.2 高分辨率谱估计 14
4 欠采样数字测频技术 20
4.1 单通道延迟欠采样 20
4.2 算法仿真 21
5 信道化测频技术 24
5.1 基于多相滤波器组的信道化方法 24
5.2 系统仿真与分析 26
5.3 两种信道化接收机模型的比较