摘要跳频通信作为现代通信的重要手段之一,目前已经在军事领域和民用领域得到了十分广泛的应用。而对跳频通信系统的参数估计的好坏和识别率的高低将直接影响到后继环节的处理,所以高效、高稳定度、高实时性的方法是现在研究的主流方向。66365
本文首先介绍了跳频通信系统的基本原理和工作方式,并对跳频序列等关键技术做了概述。其次对短时傅里叶变换(short-time Fourier transform,STFT)和平滑伪魏格纳分布( smoothing pesudo Wigner-Ville distribution,SPWVD)时频方法做了分析研究,总结了其优缺点。通过对这两种方法的分析和仿真,得到以上两种方法均能有效地进行高精度的估计,而且能保持较好的实时性能。最后,本文运用SPWVD时频方法,深入探讨了跳频系统的跳速估计、跳变时刻估计以及跳频序列估计的方法,分析了跳频信号的模型以及 SPWVD 的离散化实现过程。仿真结果表明,SPWVD在精度和实时性上都有着较好的性能。
毕业论文关键词 跳频通信 时频分析 平滑伪魏格纳 参数估计
毕业设计说明书(论文)外文摘要
Title Parameter Estimation Algorithm for Frequency-hopping Signals
Abstract
Frequency hopping communication system is one of the most important methods in modern communication, which has been widely used in military and civilian field. The quality of parameter estimation and accuracy of recognition could affect the subsequent processes. Therefore, approaches with high efficiency, stability and real time are the interesting research direction.
Firstly,this thesis introduces the basic principles of frequency hopping communication systems and frequency hopping sequence. Then short-time Fourier transform (STFT) and smoothing pesudo Wigner-Ville distribution (SPWVD) time-frequency methods are presented, and their advantages and disadvantages are summarized. Simulation results indicate that both of the methods are fairly satisfactory in the aspect of accuracy and real time. The thesis mainly focuses on the study of parameter estimation of frequency-hopping signals: hopping speed, moment and sequence.The model of hopping signals and the discretization of SPWVD are also discussed in the thesis.Finally, simulation results demonstrate that the performance of the system is preferable both in accuracy and real time.
Keywords Frequency hopping communication; Time-frequency analysis; SPWVD; Parameter estimation
目 次
1 引言 1
1.1 本文研究背景 1
1.2 本文结构安排 2
2 跳频系统概述 3
2.1 跳频通信系统原理 3
2.2 跳频序列产生 4
2.3 频率合成器 5
2.4 跳频通信系统模型 6
2.5 跳频信号仿真 7
2.5.1 基带信号的产生和MSK调制 7
2.5.2 跳频信号的载波产生 8
2.5.3 载波调制产生信道帧及其加噪 10
2.5.4 跳频信号的产生 10
3 跳频信号的时频分析 12
3.1 短时傅里叶变换