A Novel FPGA Implementation of a Wideband Sonar System for Target Motion Estimation

An FPGA implementation of a hybrid algorithm developed for target motion estimation in a wideband sonar echolocation system is presented in this paper. The compact and fast hardware architecture consists of three parts: discrete wavelet transform (DWT) filtering bank, scale optimizer and continuous wavelet transform (CWT) convolver. The algorithm initially makes use of an intelligent fuzzy system for adaptive noise cancellation, output of which is processed by the DWT filtering bank employed to further minimize the remaining noise part of the training data thus fine tuning the contact signal. The DWT denoising output is then processed by an optimal CWT convolver in order to estimate targetpsilas motion including Doppler and delay. The echolocation system was evaluated using Morlet wavelet as the transmitted signal and with the target strength of approximately -30 dB. The targetpsilas motion is estimated with 0.001 s accuracy in time domain demonstrating the capability of the FPGA architecture to provide an efficient and accurate solution in sonar signal applications.