Real-Time Adaptive Modulation Schemes for Underwater Acoustic OFDM Communication

• Main Authors: Barua, S. (Author), Chen, P. (Author), Nordholm, S. (Author), Rong, Y. (Author)
• Format: Article
• Language: English
• Published: MDPI 2022
• Subjects: adaptive modulation; Adaptive modulation; Adaptive modulation scheme; Adaptive systems; Compactdaq; CompactDAQ; Computer programming languages; LabVIEW; Orthogonal frequency division multiplexing; Orthogonal frequency-division multiplexing; orthogonal frequency-division multiplexing (OFDM); Performance; Real- time; Signal to noise ratio; Time varying channel; Time varying networks; time-varying channel; Underwater acoustic channels; underwater acoustic communication; Underwater acoustic communication; Underwater acoustic communication system
• Online Access: View Fulltext in Publisher

 Adaptive modulation received significant attention for underwater acoustic (UA) communication systems with the aim of increasing the system efficiency. It is challenging to attain a high data rate in UA communication, as UA channels vary fast, along with the environmental factors. For a time-varying UA channel, a self-adaptive system is an attractive option, which can choose the best method according to the channel condition to guarantee the continuous connectivity and high performance constantly. A real-time orthogonal frequency-division multiplexing (OFDM)-based adaptive UA communication system is presented in this paper, employing the National Instruments (NI) LabVIEW software and NI CompactDAQ device. In this paper, the received SNR is considered as a performance metric to select the transmission parameters, which are sent back to the transmitter for data transmission. In this research, a UA OFDM communication system is developed, employing adaptive modulation schemes for a nonstationary UA environment which allows to select subcarriers, modulation size, and allocate power adaptively to enhance the reliability of communication, guarantee continuous connectivity, and boost data rate. The recent UA communication experiments carried out in the Canning River, Western Australia, verify the performance of the proposed adaptive UA OFDM system, and the experimental results confirm the superiority of the proposed adaptive scheme. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.