Research And Design Of Single Carrier Iterative Frequency Domain Equalization In High Speed Underwater Communication

70%of the area of the Earth’s surface is covered by the ocean, which contains a wealth of resources. The demand for resources grows fast with the rapid development of human society, while the land’s resources have shown a trend of failure. Therefore, driven by the business interests and social development, the development of the oceans is imperative. The de-velopment of marine resources is greatly dependent on the development of underwater communication technology. However, the underwater acoustic channel is extremely complex and variable. It is very challenging to estab-lish a reliable underwater acoustic (UA) communication system (UACS).The main content of this thesis is the research and design of single carrier frequency domain equalization (SC-FDE) in high-speed UACS. Firstly, this thesis analyzes the UA channel characteristics and studies SC-FDE system’s basic technology and design. Secondly, according to the underwater acoustic channel’s time-variant characteristics, the thesis stud-ies the single-carrier frequency-domain iterative equalization (SC-IFDE) algorithm. In the SC-IFDE algorithm with soft decision feedback detection, the equalizer is applied on each data block iteratively by exploiting the feedback of the extrinsic information of equalized bits, which is fed back to the equalizer as the a-priori information for the next iteration.In addition, this thesis introduces a SC-IFDE channel tracking mod-ule, by dividing one data block into sub-blocks which are short enough to track changes of the channel. Depending on the method of using the channel impulse response in iterative process, the SC-IFDE system can be seperated into two types. One is based on channel tracking by sub-blocks recursively and the other one is based on channel tracking by sub-blocks iteratively. In the last part, this thesis uses the ocean experiment data collected by our project team in2012to prove the feasibility and effectiveness of the SC-IFDE system. And it is proved that the SC-IFDE based on channel tracking by sub-blocks iteratively works better than that based on channel tracking by sub-blocks recursively.