The Underwater Acoustic OFDM Channel Equalizer Basing On Least Mean Square Adaptive Algorithm

In this paper we proposed an approach of channel equalizer based on least mean square(LMS) adaptive algorithm Recently, there have been tremendous demands for high-speed data transmission in underwater acoustic communications. Accurate channel equalizer is necessary for coherent detection of the underwater acoustic orthogonal frequency division multiplexing (OFDM) signals. we proposed an approach using training sequence to obtain the channel information by LMS adaptive equalizer algorithm, at the receive LMS adaptive equalizer is imposed to the received signal in time domain to obtain the channel impulse response. Time-domain equalization is computationally efficient because it does not require FFT operations. Thus, this approach is very attractive for hardware implementation of an underwater acoustic OFDM receiver. then using the channel information to obtain equalize other OFDM symbol.