US 12,222,441 B2
TDM FMCW radar apparatus and signal processing method of apparatus
Yong Jae Kim, Yongin-si (KR); and Jeong Min Choi, Hwaseong-si (KR)
Assigned to SMART RADAR SYSTEM, INC., Seongnam-si (KR)
Filed by SMART RADAR SYSTEM, INC., Seongnam-si (KR)
Filed on Jan. 25, 2022, as Appl. No. 17/584,348.
Claims priority of application No. 10-2021-0117236 (KR), filed on Sep. 2, 2021.
Prior Publication US 2023/0066386 A1, Mar. 2, 2023
Int. Cl. G01S 7/40 (2006.01); G01S 13/34 (2006.01); G01S 13/58 (2006.01)
CPC G01S 7/4056 (2013.01) [G01S 13/343 (2013.01); G01S 13/583 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A signal processing method of a time-division-multiplexed (TDM) frequency modulated continuous wave (FMCW) radar apparatus, the method comprising:
a wireless transmission operation of transmitting an FMCW radar waveform signal configured such that at least three consecutive chirps included in a chirp loop of a radar signal have different periods;
a wireless reception operation of demodulating a baseband FMCW radar signal from an FMCW radar waveform signal reflected by a target, sampling a difference signal between the baseband FMCW radar signal and the transmitted signal, transforming the difference signal into a digital signal, and outputting the digital signal;
a spectrum analysis operation of determining and outputting a beat frequency and a Doppler frequency from the signal output in the wireless reception operation; and
a Doppler frequency determination operation of measuring phase differences between the at least three consecutive chirps having different periods, which are received in the wireless reception operation, and determining and outputting a true Doppler frequency from the measured phase differences and the Doppler frequency output in the spectrum analysis operation,
wherein the at least three consecutive chirps have a same frequency,
wherein both a ramp time and an idle time of a first chirp are same with a ramp time and an idle time of a last chirp, and
wherein both a ramp time and an idle time of an intermediate chirp are different from the ramp time and the idle time of both the first chirp and the last chirp.