Design And Implementation Of Multi-carrier MFSK Technology In The Underwater Acoustic Communications System

With the rapid development of marine resources exploitation and urgent necessity of national oceanic security , Underwater Acoustic Communication (UAC) technology research and project implementation have been paid much more attention . Especially a wide range of applications in underwater acoustic communication networks in recent years makes the study of acoustic communication become a hot focus all over the worldwide.In order to overcome the impact of complex channel environment on system performance in UAC, using multicarrier MFSK as the system of the communication system ,which inherits the stable reliability and also is compatible with the advantages in the high-use-rate of frequency spectrum for the Orthogonal Frequency Division Multiplexing and greater capability of resisting multi-route-interference and the frequency choice decline for the Multi-Carrier (MC) Modulation technology in this thesis.This paper mainly focused on the discussion of the several key technical implementations on the basis of the summary of UAC system, and the final design is completed as a set of the MC-MFSK acoustic communication system. Adopting the low-power-loss DSP TMS320C5509a as the core-processor in the hardware platforms while using the only resources of chips and peripherals to complete the systematical functions,including channel error-correction coding, modulators functions etc. while adopting and comparing two different transmissive methods of the DA with linear power-amplifier and PWM modulation with D-type power-amplifier in the transmitter-end;as well as the basic signal processing for receiving signals, demodulation, channel error-correction decoding, and other systematical functions have been realized in the receiver-end. The entire UAC system has been tested with a feature of real-time and good performance .