Research On Key Technology Of Underwater Acoustic Communication Based On OFDM

OFDM technology is the hot technology of underwater acoustic communication today. First introduced the OFDM-based technology,then do some theoretical and experimental about it. And put forward my own theoretical for OFDM key technology, approach also gives the results of the simulation and sea trial certificate. The main contribution of this paper made are as follows:On account of severe doppler effect existing in the wide band UWAC, a robust method for estimating the doppler shift by means of multi-tones signal is put forward; according to the sparsity property of the underwater acoustic channel impulse response, a novel channel estimating approach is given. An order recursive orthogonal matching pursuit algorithm is used to reconstruct the non-zero coefficients of the channel by inserting a small number of pilots in the system in the approach, to avoid the direct matrix inversion and reduce the computatial and engineering complexity. Analysis of the problems encountered in underwater acoustic channel communication system using OFDM technology, and design the corresponding forms of the transmitted signal. And then do simulation studiesand sea trial certificate about above theory.Study of UWAC experements. An pool trial and a sea experiment for key technologies and system performance of the OFDM system was organized respectively. The processing results of experimental data were proved that the validity and robust of the proposed Doppler estimation algorithm based on multi-tones signals and the OR-OMP algorithm. The results show that a effective information rate of187.5bps for the OFDM system was achieved with fairly lower transmited source level and BER performance.Combining the authentication OFDM communication algorithm, giving my own system design and communication design for underwater acoustic communication research focus, the UUV interworking communication, in the last. And groundbreaking use PC104bus board,and that will provide the feasibility reference for everyone who want to do UUV communication.