Dynamic radar echo digital down-conversion system and method based on FPGA (field programmable gate array)

Abstract

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.

Description

technical field [0001] The invention relates to a radar echo digital down-conversion method, in particular to an fpga-based dynamic radar echo digital down-conversion system and method. Background technique [0002] In the commonly used radar echo signal processing system, after the analog intermediate frequency real signal returned by the RF front end is converted into a digital intermediate frequency real signal by an analog-to-digital conversion device, the signal is usually processed into a digital baseband complex signal by a digital down conversion device. Then input to the signal processing device of the subsequent stage. As a key step in the radar echo signal processing system, the processing performance of the digital down-conversion device directly affects the signal processing performance of the radar system. [0003] Digital down-conversion usually consists of the following steps, band-pass filtering, parity decimation, frequency mixing, and low-pass filtering. ...

AI Technical Summary

Problems solved by technology

First, the operation of the process is complicated, and, in different environments, the location of the intercepted data may also be different, and the system maintenance is very troublesome

Second, this method is not suitable for signals with too large or too small echoes. For too large signals, this method will truncate too few bits, resulting in data overflow

For a signal that is too small, this method will truncate too much, resulting in the loss of effective information

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