빔 형성을 이용한 수중음향통신 성능 개선

Abstract

The underwater environment is characterized by doubly spread channel in the time-variant Doppler shift and delay-time spreads due to multiple paths. The characteristic of doubly spread channel leads to inter-symbol interference. Various techiques such as time-reversal processing, spatial diversity, phase estimator, and equalizer are used to mitigate inter-symbol interference. In this thesis, a spatial filter based on the conventional beamforming is proposed as a method to mitigate the inter-symbol interference that is generated in time-varying multipath channels. The proposed technique realizes coherent communications by steering the direction of the desired signals and improves the performance of underwater acoustic communication by the Signal-to-Interference plus Noise Ratio improvement achieved by the array gain.