2026-05-31T21:39:00Zhttps://riuma.uma.es/rest/oai/request

oai:riuma.uma.es:10630/396022026-02-03T10:58:59Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Cobacho Ruiz, Pablo author Cañete-Corripio, Francisco Javier author Martos-Naya, Eduardo author Fernández-Plazaola, Unai author 2022-07-29 In this paper, we present the development of a multicarrier modulation system of low complexity for broadband underwater acoustic communications (UAC), whose frequency band is located in the ultrasonic range, specifically between 32 kHz and 128 kHz. Underwater acoustic channels are recognized among the most hostile communication channels due to their strong time and frequency selectivity and, hence, the design of high-performance systems is a challenge that is difficult to resolve at the present time with state-of-art technology. The aim of the proposed system is to reach a reasonable bit rate, between 40 and 50 Kbps, over these channels that allows, for instance, the transmission of video signals of limited quality. We describe an orthogonal frequency division multiplexing (OFDM) modem prototype with a parameter setting and design specifically adapted to the channel nature. For this purpose, actual measurements carried out at the Mediterranean sea, on shallow waters, have been used to evaluate the system performance and to optimize the design. A discussion on several modulations and OFDM configurations is presented that leads to the selection of differential and non-differential quadri-phase shift keying (QPSK) as good candidates depending on synchronization capabilities. Cobacho-Ruiz, P.; Cañete, F.J.; Martos-Naya, E.; Fernández-Plazaola, U. OFDM System Design for Measured Ultrasonic Underwater Channels. Sensors 2022, 22, 5703. https://doi.org/10.3390/s22155703 https://hdl.handle.net/10630/39602 10.3390/s22155703 Acústica submarina OFDM System Design for Measured Ultrasonic Underwater Channels