US 12,455,366 B2
Radar measurement method
Arthur Hipke, Leonberg (DE); and Benedikt Loesch, Stuttgart (DE)
Assigned to ROBERT BOSCH GMBH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on Nov. 14, 2022, as Appl. No. 18/055,258.
Claims priority of application No. 10 2021 213 495.5 (DE), filed on Nov. 30, 2021.
Prior Publication US 2023/0168360 A1, Jun. 1, 2023
Int. Cl. G01S 13/58 (2006.01); G01S 13/34 (2006.01); G01S 13/931 (2020.01)
CPC G01S 13/584 (2013.01) [G01S 13/34 (2013.01); G01S 13/931 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for determining a relative velocity of a radar target, the method comprising:
(a) carrying out an FMCW radar measurement in which a ramp-shaped frequency-modulated transmit signal is sent whose modulation pattern includes a first sequence of ramps succeeding one another offset by a time interval, and at least one further sequence of ramps succeeding one another offset by the time interval, the first and the at least one further sequences being temporally interleaved;
(b) mixing down received signals to baseband signals, and, from the baseband signals, calculating a two-dimensional spectrum separately for each of the first and at least one further sequences by two-dimensional Fourier transformation, transformation taking place ramp for ramp in a first dimension, and transformation taking place via a ramp index in s second dimension,
(c) based on positions of a peak in at least two of the two-dimensional spectra of the baseband signals, determining a value for the relative velocity of a radar target;
wherein each spectra of the two-dimensional spectra formed for the first and the at least one further sequences is transformed by multiplication with a beamforming function that is a function of a velocity variable and of a time offset of the first and the at least one further associated sequences to the first of the sequences, and the relative velocity of the radar target is determined based on a coherent sum of the transformed spectra.