The invention provides a dynamic
radar echo digital down-conversion
system and method based on an FPGA (
field programmable gate array). The dynamic
radar echo digital down-conversion
system includes aband-pass filter, a dynamic truncation device, an odd-even extraction device, a
frequency mixing device and a low-pass filter, wherein the dynamic truncation device comprises a first dynamic truncation module, a second dynamic truncation module and a third dynamic truncation module, and whether truncation operation is conducted or not is decided based on different input signals and the bit widthof the
maximum amplitude value of the signals. The dynamic
radar echo digital down-conversion
system and method are based on the digital down-conversion principle, the data caching function of the FPGA and FIFO is fully used, the
maximum amplitude value of each
signal is calculated while data are cached, and then according to a unique
data truncation method, dynamic truncation of the
echo signal is completed while the useful signals are retained to the greatest extent. The digital down-conversion system can be dynamically adaptive to down-conversion
processing of radar echo signals with different intensity under different environments by combining the dynamic truncation method.