천해 수중 음향 채널에서의 주파수 선택적 페이딩 특성

Abstract

Frequency selective fading statistics of shallow water acoustic communication channel

Jong Joo Kim

Department of Information and Communications Engineering, The Graduate School Pukyong National University

Abstract The underwater acoustic channel is a time-varying multipath fading channel. The time variability of multipath is caused mainly by the boundary fluctuation and the propagation medium property time variability. In shallow water, the former is more important comparing to deep water in which refraction paths in medium is also important. The coherent components of multipath arrivals to receiver from various paths interfere with each other and cause constructive and destructive interference in received signals. This induces change of fading statistics and signal-to-noise ratio (SNR). The envelope amplitude statistics of receiving signal which defines the time varying multipath fading channel is very important for underwater acoustic communication system design and performance analysis. In this study, shallow water acoustic communication channel with only a few strong paths is modeled and analyzed based on phasor representation of path amplitude. It is found that the fading statistics distribution is determined by a frequency dependent constructive or destructive interference of multipath. Theoretical and experimental fading statistics are well matched with each other.