Implementation Of Linear Frequency Modulation Signal Based On Cordic Algorithm By FPGA

Pulse compression radar in order to ensure enough range, adopting a wide pulse emission to improve the emission of the average power, in order to improve the range resolution, it received narrow pulse by using pulse compression algorithm, so it solve the contradictions between the range and distance resolution in a good way. LFM signal is the most common signal of pulse compression radar, so studying realization of LFM signal is very important.With the rapid development of Very Large Scale Integrated circuit(VLSI), LFM signal could be generated in digital method already. Compared with the analog method, DDS (direct digital synthesis) method is more flexible and more reliable., it solved the defects of the traditional waveform generator. The DDS method adopts ROM look-up table method to generate LFM signal mainly, due to the RAM capacity limit in FPGA, it couldn’t achieve large time-bandwidth LFM signal. Fortunately, many complex function operations is difficult to use hardware circuit direct realization, but CORDIC algorithm can solve the problem through unified add and shift, so it reduces the complexity of hardware design greatly. In order to solve the shortage of the RAM resource in FPGA, the author studies the generation of LFM signal making use of CORDIC algorithm.This paper introduces CORDIC algorithm and its hardware implementation in detail. It also analyse the hardware realization process of LFM signal. And finally, it generated LFM signal with variable bandwidth and time-bandwidth on the board.