Estimation On Instantaneous Frequency Of Echo Signal Of Pallets

As an important characteristic value indicating physical substance of non-stationary signals, the instantaneous frequency has been widely used in many technical fields like Radar, Sonar, Mobile communication etc. Researches on estimation methods of instantaneous frequency have great theoretical significance and much practical value. Microwave interferometer designed according to Doppler Effect is used for measuring the motion parameters of pellets in gun bores, which is the important guarantee in improving the performance of guns and pellets. Echo signal of pallets is actually liner frequency modulation (LFM), which includes all information of pellets’motion parameters in gun bores. Therefore, the instantaneous frequency of pallets’echo signals is important research subjects for studying the motion features of pallets in gun bores.This paper firstly provides an comprehensive description of the development of the research on instantaneous frequency, put forwards the basic concept of the instantaneous frequency, ways of definition and the research background; secondly, this thesis focuses on those echo signals of pallets whose instantaneous frequency changes more great, and thoroughly analyses and study the estimation methods of their instantaneous frequency from different aspects. In terms of different frequency ranges and different application environments, signals can be divided into two categories: signals of instantaneous frequency changed in a small range and signals of instantaneous frequency changed in a large range. In terms of the frequency components included in signals, signals can be divided into single component signals and multi-component signals.Take those echo signals of pallets whose instantaneous frequency changes more great as an example, the instantaneous frequency of single component LFM signals and multi-component LEM signals are estimated by using WVD and W-H. Experiment result getting from estimating instantaneous frequency of single component LEM signals shows that W-H can better suppress the noise than WVD. Experiment result getting from estimating instantaneous frequency of multi-component LEM signals further proves that W-H performs better than WVD in suppressing the noise. Even when the signal to noise ratio is-3dB, WVD can still do well in estimating signal frequency. The final part of this thesis focuses on the algorithm. With hardware design, algorithm can be realized and then be verified to improve its features.