It seems that the algorithm mentioned in the article is here [1], [2]. It has been close to 20 years before a working prototype being implemented, I wonder what

It seems that the algorithm mentioned in the article is here [1], [2]. It has been close to 20 years before a working prototype being implemented, I wonder what caused the delay in the implementation? The original underwater channel model and propagation however, fittingly the Professor's most cited paper, came later which kind of strange since you usually come up with channel model and propagation first before the modulation, not the reverse [3]. [1] Low Complexity OFDM Detector for Underwater Acoustic Channels (OCEANS 2006): https://ieeexplore.ieee.org/document/4098993 https://ieeexplore.ieee.org/document/4098993 [2] MIMO-OFDM Over An Underwater Acoustic Channel (OCEANS 2007): https://ieeexplore.ieee.org/document/4449296 https://ieeexplore.ieee.org/document/4449296 [3] Underwater acoustic communication channels: Propagation models and statistical characterization (IEEE Communications Magazine 2009): https://ieeexplore.ieee.org/document/4449296 https://ieeexplore.ieee.org/document/4449296