Study On Embedded Signal Processing System Of Digital ADCP

This thesis is a sub-part of the project, "A small multi-parameters marineenvironment detection buoy", in major project Marine Monitoring Technology underChina national 863 programs. The primary work is to develop and study theembedded system of digital Acoustic Doppler Current Profiler (ADCP) . In order to realize digital system totally, we have been designing, debugging andsimulating. Meanwhile the preferable results are received. All these are based onembedded methods and Doppler theory. Firstly, the meaning of embedded system is analyzed. Secondly, the history, sorts,and functions of ADCP are introduced which indicate that ADCP is very significant toacquiring and enriching exact real-time oceanic data, adapting to increasinglydeveloping rights and management of ocean and speeding the national economy andnational defence. DSP is the core of the system, and it exchanges order keywords by Dual-portRAM, realizes logic control and part algorithm by CPLD(Complex ProgrammableLogic Device),takes different work modes based on DDS(Direct Digital Synthesis)and receives data by PDC(Programmable Digital Down-Converter) which makessystem flexible. The major innovations achieved in the dissertation are as follows: 1. Mixing and filtering are implemented by digital technique. And the parameters can be altered in real-time. 2. Data space multiplexing and PN(pseudo noise) code are realized in CPLD. 3. Complex self-correlation technique is accomplished in DSP. 4. Producing single-tone, bpsk(binary phase shift keying), chirp signals by setting flexible parameters in DDS (Direct Digital Synthesis).