Frequency reversal-based inter-carrier interference mitigation for underwater acoustic OFDM communications

Abstract

Orthogonal-frequency-division-multiplexing (OFDM) modulation has been intensively studied in underwater acoustic (UWA) communications recently for its ability to tackle large delay spread channels. Nevertheless, the inter-carrier interference (ICI) caused by Doppler spread of UWA channels degrades the system performance significantly. This paper proposes the concept of frequency reversal (FR) dual to time reversal (TR), as well as a feasible FR scheme. FR can compress the frequency spread caused by Doppler, and hence eliminate the ICI in OFDM communications. Furthermore, FR has similar advantages as TR: 1) low computational complexity and 2) robustness against complicated and changeable channels. Numerical simulation verifies the effectiveness of the proposed FR scheme as an ICI mitigation technique for UWA OFDM communications.