The Underwater Acoustic OFDM Channel Estimation Based on Wavelet and MMSE

In this paper we proposed a novel approach of channel estimation based on wavelet and MMSE. Recently, there have been tremendous demands for high-speed data transmission in underwater acoustic communications. Accurate channel estimation is necessary for coherent detection of the underwater acoustic orthogonal frequency division multiplexing (OFDM) signals. Pilot-assisted channel estimation using training sequence to obtains the channel information, the transmitter rate decrease rapidly along with the number of training sequence increase. We proposed a approach using less training to estimate the channel by wavelet and minimum mean Square error (MMSE), the pilot sequence before transmitting is convolutionnal encoded for the correlation of symbol, at the receive wavelet denoise is imposed to eliminate the Additive white Gaussian noise (AWGN) then using MMSE to obtain others frequency bin channel impulse response inner the same block.