Dr Andrew C. Singer

This talk will discuss one of the most challenging digital communications channels on the planet - the underwater acoustic channel. Through aggressive use of signal processing and forward error correction, a number of successful methods have been developed over the last two decades for sending digital information through the underwater acoustic medium. In this talk, we will explore some of the biggest challenges and greatest differences between underwater acoustic communications and other forms of wireless communication. These include time-varying multipath, propagation velocity that varies with depth and temperature, and absorption that is a strong function of frequency, giving rise to bandwidth-to-carrier ratios of 100 percent or more. Additionally, when an underwater acoustic modem is installed on a mobile platform such as an underwater vehicle, a buoy, or a surface vessel, Doppler effects distort the acoustic signal significantly. The acoustic path between a surface vessel and an underwater vehicle, for example, can experience Mach numbers of more than one percent - five orders of magnitude more severe than RF wireless channels - and would be catastrophic if not compensated dynamically. We will discuss a sample-by-sample, recursive resampling technique, in which time-varying Doppler is explicitly modeled, tracked and compensated. Integrated into an iterative turbo equalization-based receiver, this Doppler compensation technique enables underwater acoustic communication over a wide range of bandwidths and vehicle velocities. Some of the field data that will be discussed stems from the MACE10 experiment conducted in the shallow waters 100 km south of Martha’s Vineyard, MA. Under challenging conditions (harsh multi-path, ranges up to 7.2 km, SNRs down to 2 dB and relative speeds up to 3 knots) we obtained a data rate of 40 kbits/s using 10 kHz of bandwidth. Additional experimental results will be discussed from at-sea tests as well as tests in our acoustic communications tanks on campus in which we achieve data rates of several Mbps to over 100Mbps.

Biography: Andrew C. Singer received the S.B., S.M., and Ph.D. degrees, all in electrical engineering and computer science, from the Massachusetts Institute of Technology. From 1996 to 1998, he was a Research Scientist at Sanders, A Lockheed Martin Company in Manchester, New Hampshire. Since 1998, he has been on the faculty of the Department of Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign, where he currently holds a Fox Family Professorship in the Electrical and Computer Engineering department. His research interests include signal processing and communication systems.

In 2000, he co-founded Intersymbol Communications, Inc., a fabless semiconductor IC company, based in Champaign, Illinois, which built the world’s fastest signal-processing-enhanced receivers for 10Gb/s optical communications. In 2007, Intersymbol Communications, Inc. was acquired by Finisar Corporation (FNSR). He continues to work in areas related to signal processing algorithms and their potential to enhance mixed-signal analog and digital circuits both in his research and as Assistant Director of the SRC-funded Systems On Nanoscale Information fabriCs (SONIC) center.

He received the National Science Foundation CAREER Award in 2000; in 2001 he received the Xerox Faculty Research Award, and in 2002 he was named a Willett Faculty Scholar. In 2005, he was appointed the Director of the Technology Entrepreneur Center at the University of Illinois, where he directs a wide range of entrepreneurship activities in the College of Engineering. In 2006 he received the IEEE Journal of Solid State Circuits Best Paper Award for the paper entitled “An MLSE Receiver for Electronic Dispersion Compensation of OC-192 Fiber Links.” In 2008, he received the IEEE Signal Processing Magazine Award for the paper entitled “Turbo Equalization.” In 2009, he was elected Fellow of the IEEE “for contributions to signal processing techniques for digital communication,” and in 2014, he was named as a Distinguished Lecturer of the IEEE Signal Processing Society.

Email:

Address:University of Illinois at Urbana Champaign, 110 CSL, 1308 West Main Street, Urbana, Illinois, United States, 61801

Dr Andrew C. Singer

Biography:

Email:

Address:Urbana, Illinois, United States