Symbol rate estimation of digital signals based on wavelet transform

Automatic modulation identification of communication signals plays an important role in electronic surveillance and electronic warfare systems. How to estimate symbol rate of digital signals without any apriori knowledge is a significant problem in the field of modulation identification. The wavelet transform (WT) can effectively extract the transient characteristics in a digital communication signal. A method was discussed to estimate symbol rate of MPSK signals using wavelet transform without any apriori knowledge. In matlab simulation, if a proper wavelet function is chosen, the WT magnitude of digital communication signals will peak at the time where phase changes occur. Consequently the separation of the peaks is an integral multiple of the symbol period. In addition, computer simulation results show the good performance of the method even at low Carrier to Noise Ratio (CNR).