The Study Of Code Rate Estimation Method Based On Wavelet Transform

Communication signal processing is an important technology in wireless communication environment. As countries scholars’constant research and exploration of the theory of technology, modern communication technology not only widely used in our life, but also in the military field plays a very important position. The study the modulation signal parameter estimation plays a significent part in intercept the enemy communication signals and our information security. The technology is needed to identify the signal modulation style and estimate signal parameters in noisy environment, and be used for extract the characteristic of the signal. Symbol rate is one of the most important parameters to be estimated. Thus this article propose a method to estimate the symbol rate of modulated signal.Research based on the wavelet analysis theory and through multi-scale analysis of signal and extract QPSK signal element between the phase transient information. Then based on processing wavelet transforming amplitude to achieve accurate estimates of the QPSK signal symbol rate.This method has the advantage of QPSK signal without any prior knowledge, also do not need to proceed signal demodulation, thus avoiding the estimated parameters or introduced other demodulation error, so it gains higher estimation precision and can still estimated accurately under low signal-to-noise ratio. So as to lay a solid foundation for the subsequent signal processing work.