Manolakis, K.K.ManolakisKrüger, U.U.KrügerKrüger, K.K.KrügerEstevez, M.A.G.M.A.G.EstevezMikulla, S.S.MikullaJungnickel, V.V.Jungnickel2022-03-112022-03-112011https://publica.fraunhofer.de/handle/publica/374015In this paper we discuss theory, system design and implementation of an acoustical communication system. We aim to transmit data from the bottom of a borehole to the surface with data rates of at least 200 bps. As a technical solution we use acoustic waveguide communication with adaptive OFDM over a baseband frequency spectrum from 0 to 9 kHz. We characterize hardware components and discuss how to deal with their non-linearities. Furthermore we estimate the signal-to-interference due to these non-linearities and adapt modulation and coding over frequency correspondingly. We evaluate the codeword error rate by link-level simulations based on 3GPP LTE specifications and estimate an upper bound for the achievable data rate.en621conference paper