FEATURES EXTRACTION OF TWACS SIGNAL BASED ON TIME-FREQUENCY ANALYSIS
Shaoqing Zhang · Proceedings of the CSEE · 2004
The system of multi channels operating simul-taneously can not accomplished based on digital differential technique which can not recognize the single impulse signal of TWACS (Two Way Automatic Communication System). This paper aims to find out an effective method to deal with this problem based on time-frequency analysis. The contradiction stands out between the time-resolution and frequency-resolution when the STFT (Short Time Fourier Transform) is used, while the hard time-resolution is presented in low frequencies by the MRA (Multi-Resolution Analysis). If two methods is put forward, it can have good characters in both the time and frequency localization. The enough features of signal in time and frequency domains could be obtained by STFT based on MRA. The eigenvalue parameters which can recognize the single impulse of TWACS effectively are constructed by the self covariance matrix of characteristic vectors.