Multichannel time-reversal processing for acoustic communications in a highly reverberant environment.
The development of time-reversal (T/R) communication systems is a recent signal processing research area dominated by applying T/R techniques to communicate in hostile environments. The fundamental concept is based on time-reversing the impulse response or Green's function characterizing the uncertain communications channel to mitigate deleterious dispersion and multipath effects. In this paper, we extend point-to-point to array-to-point communications by first establishing the basic theory to define and solve the underlying multichannel communications problem and then developing various realizations of the resulting T/R receivers. We show that not only do these receivers perform well in a hostile environment, but they also can be implemented with a "1 bit" analog-to-digital converter design structure. We validate these results by performing proof-of-principle acoustic communications experiments in air. It is shown that the resulting T/R receivers are capable of extracting the transmitted coded sequence from noisy microphone array measurements with zero-bit error.
Candy
James V
JV
University of California, Lawrence Livermore National Laboratory, PO. Box 808, Livermore, California 94551, USA. candy1@llnl.gov
Poggio
Andrew J
AJ
Chambers
David H
DH
Guidry
Brian L
BL
Robbins
Christopher L
CL
Kent
Claudia A
CA
D000162:Acoustics; D003142:Communication; D004777:Environment; D006801:Humans; D009622:Noise / Q000009:adverse effects*; D013997:Time Factors