Abstract: A radar system and method for calibrating a radar system, the method including the steps of: measuring a set of azimuth angles of the radar system to obtain a plurality of measured azimuth array responses, wherein the radar system is physically rotated about a first axis of the radar system between each azimuth angle measurement; measuring a set of elevation angles of the radar system to obtain a plurality of measured elevation array responses, wherein the radar system is physically rotated about a second axis of the radar system between each elevation angle measurement; obtaining an azimuth calibration matrix based on the plurality of measured azimuth array responses and an elevation calibration matrix based on the plurality of measured elevation array responses; and configuring the radar system to apply the azimuth calibration matrix and the elevation calibration matrix to one or more antenna array responses.

Abstract: A vehicle radar system and calibration method that provide for system calibration so that target object parameters can be calculated with improved accuracy. Generally speaking, the calibration method uses a number of hypothesized calibration matrices, which represent educated guesses for possible system or array calibrations, to obtain a number of beamforming images. A blurring metric is then derived for each beamforming image, where the blurring metric is generally representative of the quality or resolution of the beamforming image. The method then selects hypothesized calibration matrices based on their blurring metrics, where the selected matrices are associated with the blurring metrics having the best beamforming image resolution (e.g., the least amount of image blurriness). The selected hypothesized calibration matrices are then used to generate new calibration matrices, which in turn can be used to calibrate the vehicle radar system so that more accurate target object parameters can be obtained.

Abstract: A vehicle radar system, such as a multiple input multiple output (MIMO) radar system, for estimating a Doppler frequency shift and a method of using the same. In one example, a modulated signal is mixed with an orthogonal code sequence and is transmitted by a transmit antenna array with a plurality of transmitting antennas. The signals reflect off of a target object and are received by a receive antenna array with a plurality of receiving antennas. Each of the received signals, which likely includes a Doppler frequency shift, is processed and mixed with a number of frequency shift hypotheses that are intended to offset the Doppler frequency shift and result in a series of correlation values. The frequency shift hypothesis with the highest correlation value is selected and used to correct for the Doppler frequency shift so that more accurate target object parameters, such as velocity, can be obtained.

Abstract: A method for transmit beamforming in a MIMO antenna for a radar system having N transmit antennas includes acquiring a coding matrix defining a desired field-of-view, generating a transmit signal matrix based on a singular value decomposition (SVD) of the coding matrix, wherein the columns of the transmit signal matrix are transmit signal vectors formed from the singular vectors corresponding to the maximal singular values of the coding matrix based on the SVD, the transmit signal vectors defining spatial codewords, and transmitting signals in sequences over the N transmit antennas according to the transmit signal matrix, the sequences correspond to the spatial codewords from the transmit signal vectors, wherein each sequence is defined by a number of spatial codewords transmitted in a single repetition sequence interval, and wherein transmitting the spatial codewords according to the transmit signal matrix enables beamforming of the transmitted signals to the desired field-of-view.