Design And Implementation Of Underwater Acoustic Communication System Based On DSP

People gradually realize the importance of developing ocean, and oceanographic engi-neering has become a hot research topic in modern science and technology. The underwater acoustic communication is one of key technologies in the development of ocean resources and development of the marine military, so the research on underwater acoustic communica-tion system has very important scientific significance and application value. OFDM is widely used in modern wireless communication field for its high spectrum utilization and ability of anti-multi-path interference, so we can apply this technique in the field of underwater acoustic communications. Software defined radio(SDR) use software to realize radio communication function, which is realized by hardware in the traditional method, and it has the advantages of low cost, flexibility and openness. We use SDR to realize the underwater acoustic communi-cation system, which can greatly simplify the hardware, reduce the cost and easy system up-grade.Considering the advantages of OFDM and SDR, this paper designs and realizes real time underwater acoustic communication system with these two technogies. OFDM and SDR both require a lot of data computation, DSP is the core part of implementation of them because it has powerful computingability, that is able to realize various signal processing algorithms. This paper chooses TI OMAP-L138 processor as the platform. OMAP-L138 is a low-power processor based a C6748 DSP and an ARM926EJ-S core, which has powerful capability of data processing and system control, so it is very suitable for underwater acoustic signal processing. The system also use TLV320AIC3106 audio codec as the A/D and D/A compo-nents. The main work of this paper is realizing a series of real-time processing of underwater acoustic signals with C++ programming under CCS integrated development environment. In the paper detailed discuss the system implementation framework, software and hardware de-sign and algorithm implementation steps. The hardware part consists of A/D, D/A mod-ule, power amplifier module, underwater acoustic transducer and core processor. The main difficulty of the algorithm is the timing synchronization and channel estimation.Finally, we verified that this system has the ability of real-time transmission of data and reliable transmission performance by underwater experimental test in indoor pool.