Mimo-radar measuring method

Abstract

The invention relates to a MIMO-FMCW radar sensor and to a MIMO-time-division multiplexing method for locating a radar target (18), wherein a FMCW radar measurement is carried out using a transmission signal, of which the modulation patterns for different transmission switching states (m), which differ in the selection of antenna elements (12) used for transmitting, comprise time-interleaved sequences (22; 26; 32; 36) of ramps (24; 28; 34; 38); ambiguous values for the relative speed (v) of the radar target (18) are determined from a position (k, l) of a peak in a two-dimensional spectrum (56); phase relationships between spectral values of spectra (X) are checked for conformity with the phase relationships (a (v,m)) expected for a plurality of the determined values of the relative speed (v); based on said phase relationships, from the determined periodic values of the relative speed (v), an estimated value for the relative speed (v) of the radar target (18) is selected; and based on amplitudes and / or phase relationships between obtained base band signals (b), the angle of the radar target (18) is determined.

Description

technical field [0001] The invention relates to a method for locating radar targets by means of an angle-resolved MIMO-FMCW radar sensor, wherein the received signal is down-mixed with the transmitted signal to a baseband signal and according to the use of the radar sensor The amplitude and / or phase relationship between the baseband signals obtained with different choices of transmitted and received antenna elements determines the angle of the located radar target. [0002] The invention also relates to a radar sensor, in particular for a motor vehicle, which is designed to carry out the method. Background technique [0003] FMCM radar sensors are used in motor vehicles for detecting the traffic environment, especially for locating other vehicles. The positioning results can be used for various assistance functions, for example for automatic distance adjustment, automatic collision warning or also for automatically triggering emergency braking in the event of a severe colli...

AI Technical Summary

Problems solved by technology

However, the code division multiplexing method requires high outlay and can only achieve a limited orthogonality of the signals

In frequency division multiplexing, there are the following disadvantages: the phase and Doppler frequency shifts are related to the corresponding wavelength

However, there is the problem that the relative movement of the located object combined with the time difference between the measurements with different switching states leads to phase differences which make subsequent angle estimation difficult

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