Research And Design Of Underwater Acoustic Communication System Based On OFDM/OQAM

As people pay more attention to the marine resources, underwater acoustic (UWA) communication is getting more and more attention as well. However, marine environment is very different from the land, many communication technologies in the land can’t be directly applied to the UWA communication. In addition, due to the UWA channel have severe time-varying and frequency selective fading and so on, so the construction of the UWA communication system is a great challenge.OFDM/OQAM technology uses a set of filters obtained by the same prototype to divide the spectrum; it also can allocate bandwidth flexible. It uses good time-frequency focusing pulse to resist ISI and ICI without CP, it also has high spectrum efficiency, low band radiation. In addition, the technique preserves the partial orthogonality, which makes the receiving system relatively simple. So we try to study and design the UWA communication system based on it.Firstly, the characteristics of UWA channel are introduced. At the same time, it studies a kind of UWA channel model which considering various kinds of ocean environment factors, and gives the simulation results of the UWA channel. Secondly, it introduces the theory of OFDM and OFDM/OQAM systems, the fast implementation and the generation of the passband signal. The performance of these two systems in different channel models is also compared at the same time. Thirdly, the channel estimation technology of OFDM/OQAM system is analyzed theoretically, and it compares the performance of different estimation methods to find a more suitable technology for the system. Finally, it tells how to build a UWA communication experiment platform using the PCI-9222 data acquisition card, UWA transducer and so on. On the basis of previous theoretical research, some key functional modules of OFDM/OQAM UWA communication system based on C language are implemented, such as the generation of OFDM/OQAM passband signal, controlling data acquisition card to achieve the signal transmission and collection and processing of received data. It first verify the correctness of the system by a sine wave in C language, then the OFDM/OQAM system with different parameters is applied to the experimental platform, which realizing data transmission and reception, bit error rate statistics, and tests the performance of IAM channel estimation in a given wireless multipath channel. All of this provides a simulation platform for the construction of the actual UWA communication system.