Carrier Frequency And Code Rate Estimation Of Communication Radiation Source

With the development of communication technology information warfare has become an indispensable part of modern warfare. In order to adapt to the future digital battlefield the development of communication countermeasures is very essential, communication countermeasures is based on accurate communication reconnaissance, namely signal intercept and analysis. Only on the basis of accurate knowledge of the signal parameter, can we do a reconnoitre effectively. Therefore, recognition of signal parameters becomes very important in which estimation of carrier and code rate is essential and is basis for many subsequent recognition.This thesis studies the carrier and code rate estimation of common signals (modulated by MASK、MPSK、MFSK、QAM) based on the summarization of previous studies.Using the method of time-frequency analysis and wavelet transform, the different modulated signal carrier and code rate can be estimated. For carrier estimation, combined with the existing methods, this thesis use Welch method to estimate the signal power spectral density, and then extract the carrier frequency, combining the peak extraction and band center method to improve recognition accuracy. For code rare estimation, in condition of shaping filter and noisy channel, this thesis adjust and improve the original algorithms, according to the characteristics of various types of modulated signals. Edge extraction-spectrum analysis method is used to estimate the MASK signals, max-slope method is used to estimate the MFSK signals, and wavelet transform method is used to estimate the MPSK signals, At last, this thesis propose a new algorithm that do not rely on modulation, and give simulation results respectively.