Research On Signal Modulation Recognition And Parameter Estimation Of Oth Ground Wave Radar

Radar signal recognition technology is an important research in the field of electronic reconnaissance and countermeasures. In this paper, LFM and BPSK, commonly used in high frequency ground wave radar, are analyzed and recognized. Modulation pattern identification and parameter estimation are simulated under the Gaussian white noise background.Firstly, LFM and BPSK, commonly used in HF ground wave radar, are introduced and analyzed their time and frequency features. In order to distinguish the modulation pattern and parameter of radar signal and recognize the radar signal effectively, the features of different radar signal must be analyzed to get the characteristic that can reflect the difference, which is called feature extraction. In this article, from the view of intrapulse modulation characteristics, the features of instantaneous frequency and time-frequency distribution are analyzed, the different features of different signals are extracted. On the basis of the extracted features, the instantaneous frequency of different radar signals are distilled based on instant autocorrelation method and phase frequency measuring method, and time-frequency distributions are extracted by STFT, WVD method respectively. Based on the characteristics of instantaneous frequency and time-frequency distributions respectively, modulation pattern identification and parameter estimation of the HF ground wave radar are studied. Different modulation patterns of radar signal are identified, and the recognition probabilities are analyzed under different signal-noise ratio. The parameters of different radar signals are extracted, and the extraction accuracies are analyzed under different signal-noise ratio. his paper proposes a combination of short-term Fourier transform and wavelet transform the two-phase pulse coded signal analysis algorithms, the simulation of the two-phase pulse code modulation parameters from real-time performance has improved significantly. To the linear frequency modulation signal, mainly to a transformation, Radon-Ambiguity transform an analysis of noise in different circumstances of the simulation, the various methods of calculation error and also an analysis of results showed that Radon-Ambiguity is a precision, A small amount of calculation method of calculation. Next on the radar pulse width, repeated intervals, such as time-domain parameters extraction methods were studied. The time domain parameter's extraction has used based on the instantaneous autocorrelation radar time domain parameter extraction algorithm, may obtain the very high pulse parameter measuring accuracy, the algorithm is simple, and the operand is not big. This research is worked under the circumstances of single carrier and additive white Gaussian noise, so the study is only applied to some simple situations. The situations of multi-carrier, non-additive white Gaussian noise or colored noise, are the further work of HF ground wave radar signal recognition research.