title: Bidirectional equalization for underwater acoustic communication.
abstract: The bidirectional decision feedback equalizer (BiDFE) that combines the outputs of a conventional decision feedback equalizer (DFE) and backward DFE can improve the performance of the conventional DFE by up to 1-2 dB based on simulations. In this letter, the BiDFE concept is extended to multichannel time reversal communications involving a DFE as a post-processor. Experimental data collected in shallow water (10-20 kHz) show that the performance can be enhanced by 0.4-1.8 dB in terms of output signal-to-noise ratio. In particular, a larger improvement (e.g., 1.8 dB) is achieved for time-varying channels where the channel diversity in opposite directions is more profound.
authors.affiliation: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0238, USA. hcsong@ucsd.edu
authors.forename: H C
authors.initials: HC
authors.lastname: Song