Characterization and Modeling of Frequency-Selective Ship-to-Ship Channels

Abstract

Recent expansion of wireless radio frequency (RF) communications services to the maritime environment has attracted increased attention to propagation and channel modeling over the sea surface. The study of RF maritime propagation has a long history, but much research is still needed to characterize and model the ship-to-ship communication channel. In this paper, the phenomenon of the ship-to-ship channel being frequency selective is introduced. It is demonstrated that this frequency selectivity depends on signal bandwidth and link range, but not on delay spread, a metric typically applied in classifying terrestrial fading channels. Another distinctive feature of this channel is that the sea surface-reflected multipath delay is less than 1 nanosecond. Taking the extremely short delay into account, modeling of the ship-to-ship channel is provided for waveform performance analysis. Performance of coherent binary phase-shift keying (BPSK) is evaluated using the model developed. Results show that the BPSK performance degradation due to maritime fading can be substantial, especially for wideband signals, producing irreducible errors.