Acronym | NUACE |
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Name | Non-chooperant Underwater Acoustic Channel Estimation |
Funding Reference | FCT - POSI/CPS/47824/2002 |
Dates | 2004-01|2006-12 |
Summary | Channel estimation is a common problem to many fields of research and,in particular, in underwater acoustics where the received signal is prone to severe time-space variability, strong multipath, dispersion and reverberation. Classical deconvolution methods attempt to estimate the parametric filter that best matches the medium response to a test input signal. These approaches mainly suffer from two well known drawbacks: one is the need for a known input signal, thus reducing its practical feasibility and efficiency and, two, is that the estimation process is started from scratch at each single environmental or geometric change between source and receiver(s), what makes it extremely slow. This project intends to develop and test the experimental feasibility of environmental model-based methods to estimate the channel impulse response. Environmental model-based techniques are drawn from physical representations of the medium of propagation through the solution of the wave equation and boundary conditions. Searching for the environmental parameters that provide the best fit between the model-based replicas and the actual received signal can be viewed from three advantageous aspects: one is that there is no need for a known (deterministic) excitation of the medium, so the identification can be performed in a blind fashion, two, is that the search is reduced to the space covered by the solutions of Objectives: 1. To develop optimization techniques for blind estimation of the environmental parameters that “focus” the source position and received to model data fitness. These parameters would provide the environmentally optimum channel impulse response at a given sensor; |
Research Groups |
Signal and Image Processing Group (SIPG) |
Project Partners | CINTAL, IH |
ISR/IST Responsible |
[1] Sérgio Jesus, António Silva, "Time reversal and spatial diversity: issues in a time varying geometry test", Proc. Conference on High Frequency Ocean Acoustics, San Diego, USA, 2004 - PDF