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On the Effect of Channel Knowledge in Underwater Acoustic Communications: Estimation, Prediction and Protocol

Authors :
Andrea Petroni
Gaetano Scarano
Roberto Cusani
Mauro Biagi
Source :
Electronics; Volume 12; Issue 7; Pages: 1552
Publication Year :
2023
Publisher :
Multidisciplinary Digital Publishing Institute, 2023.

Abstract

Underwater acoustic communications are limited by the following channel impairments: time variability, narrow bandwidth, multipath, frequency selective fading and the Doppler effect. Orthogonal Frequency Division Modulation (OFDM) is recognized as an effective solution to such impairments, especially when optimally designed according to the propagation conditions. On the other hand, OFDM implementation requires accurate channel knowledge atboth transmitter and receiver sides. Long propagation delay may lead to outdated channel information. In this work, we present an adaptive OFDM scheme where channel state information is predicted through a Kalman-like filter so as to optimize communication parameters, including the cyclic prefix length. This mechanism aims to mitigate the variability of channel delay spread. This is cast in a protocol where channel estimation/prediction are jointly considered, so as to allow efficiency. The performance obtained through extensive simulations using real channels and interference show the effectiveness of the proposed scheme, both in terms of rate and reliability, at the expense of an increasing complexity. However, this solution is significantly preferable to the conventional mechanism, where channel estimation is performed only at the receiver, with channel coefficients sent back to the transmit node by means of frequent overhead signaling.

Details

Language :
English
ISSN :
20799292
Database :
OpenAIRE
Journal :
Electronics; Volume 12; Issue 7; Pages: 1552
Accession number :
edsair.doi.dedup.....a749d8b9a4a7d6235ebedb2706db2373
Full Text :
https://doi.org/10.3390/electronics12071552