The Research Of Underwater Acoustic Communication Based-on OFDM

The underwater acoustic communication is more and more important in modern ocean development and utilization. But because the underwater channel has the character that is time variable and frequency selective fading ,The underwater communication is all restricted with bandwith and multipath.Orthogonal Frequency Division Multiplexing(OFDM) has some good character. The attraction of ofdm is that ofdm has a very compact spectral utilization and can avoid multipath. In an ofdm scheme, a large number orthogonal overlapping, narrow band subcarriers, transmitted in parallel, that can make the transmission speed higher. Ofdm signal that added the cyclic prefix can well prevent from generating intersymbol interference, so we can receive the correct signal in receive system through simplely channel coding. Ofdm has been applied abroadly in hign speed data transmitted system, and has a good foreground in underwater communication.This paper organizes discussion around the model of ofdm system, and designs a receive system in that we choose TMS320VC5509A with the peripheral equipments to realize the underwater communication.The research of the paper that we have done include:1,Analysing the model of ofdm system in underwater communication, giving the detailed system parameter.2,Designing the hardware circuit of ofdm system, which include the board design, the schematic diagram design, the electric circuit board design, the electric circuit board weld and debugging.3,Using assemble language and c language to compile FFT,QDPSK,Synchronization,RS code,Viterbi encode in the hardware system...