Underwater acoustic communication using time reversal - OCEANS ...
energy back to a probe source location despite the complexity of the propagation channel. A probe source pulse is transmitted and a complicated multipath signal is measured by an array of source/receiver elements. The signal is time reversed and retransmitted into the ocean. The time-reversal process recombines this ...
experiments took place in 1996 and 1997 using a 450 Hz source/receive array off ..... broadside transmissions can suppress dispersion, the acoustic energy ...
was 2 ms. Using binary phase shift keying (BPSK), one bit of information (1 or 0) is encoded on each symbol, and has two possible phases 180° apart (e.g. 0° ...
Time reversal, or phase conjugation in the frequency domain, is a process where a ... cation, where the reception is relatively free of multipath contamination.
response measured at a distant source/receive element while listening at the .... Imaging of complex media with acoustic and seismic waves, Topics Appl. Phys.
Royal Institute of Technology (KTH). SE-100 44 Stockholm, ... be a promising technique in next generation wireless ... cooperative communication system with limited feedback. Minimum ... same advantages as those found in MIMO. There are.
6kHz; number of subcarriers: 128; subcarrier space: 46.8Hz; symbol duration: 21.3ms. = 10 . Figure 2 shows simulation results of performance of. AF cooperative ...
software, test channels and user manual are available for download from [17]. ... Another advantage of direct replay over stochastic replay is that the code is simple, ... Oslofjord) and NCS1 (Norway â Contintental Shelf), suspended in the water ..
... impulse response strongly depends on the kind of signal used to probe the un- ... 2. Examples of measured impulse responses and power delay profiles. (a) Med. Sea: 1000 m .... nitude and phase of the channel fluctuate compared to the delay requir
data collection, pollution monitoring, offshore exploration and tactical ... is a need to deploy underwater networks that will enable real time monitoring of selected .... One possible solution is to attach each uw-sensor node to a surface buoy, ...
In the ocean, the detection of this tone is complicated by fading due to propagation, changes in the mechanical operating state of the source, and Doppler.
IEEE 802.11g, IEEE 802.16 broadband wireless access system , and HDTV. ... simulator and software modem to quantify the channel- induced distortion of ...
compared with l2 method using numerical and at-sea data with various numbers of samples and with background noise levels. [Work was funded by ONR.] Index TermsâSonar Signal Processing, Inverse Problems, Fourier Analysis. 1. Introduction. One type o
distortion corresponds to the varying degrees of attenuation encountered by light ... Then, He et al. [9,. 10] proposed the scene depth information-based dark.
xD. A. W. â. â . +. â . = λ λ λ λ λ λ. (1). At the scene point x, the artificial light ..... R q y eqyfqyf. W Ï. (18) where q is the coordinate of support pixel centered around.
The training set consisted of about 500hrs of audio. The LDA feature vectors were obtained by first com- puting 13 ... Again, Hybrid Monte Carlo seems to be best among .... 6th European Conference on Speech Communication and Technol-.
shape parameter), Chi-square, and of course the diagonal and full covariance ..... Again, Hybrid Monte Carlo seems to be best among the Markov Chain .... Carlo methods,â Dept. of Computer Science, University of Toronto,. Tech. Rep.
