Evaluation and compensation of frequency dependent path loss over OFDM subcarriers in UAC

Abstract

The underwater acoustic communication (UAC) channel presents severe time, space, and frequency selectivity that makes it difficult to achieve high data rate communication. In the recent years OFDM is used to resolve primarily frequency selectivity among these problems. Due to high absorbency of water over small frequency range path loss may be highly variable over OFDM subcarriers. This paper will evaluate this varying path loss and present algorithm to compensate such path loss using adaptive power control, adaptive modulation order, and adaptive BW. To the best knowledge of the authors, evaluation and compensation of varying path loss in the proposed method has not been presented before. Thus this research presents a valuable work in this domain.