Compensation of Motion-Induced Phase Errors in TDM MIMO Radars

Abstract

For high-resolution direction of arrival estimation, a wide aperture is necessary. This can be achieved with multipleinput multiple-output (MIMO) radars, which offer a wide virtual aperture. However, the requirement of orthogonal transmit signals has to be satisfied for their operation. Although time division multiplexing (TDM) of the transmit elements is an orthogonality realization with low hardware effort, phase errors occur in nonstationary scenarios. This work briefly discusses the problem of the motion-induced phase errors and describes processing steps to mitigate them without additional effort. The proposed technique is demonstrated with simulation and measurement data.

Radar Sensors for Autonomous Driving: Modulation Schemes and Interference Mitigation

“…This error is usually either neglected for small velocities or is compensated by a double or overlapping element in the virtual aperture [39]. In [40] it is shown that such an overlapping element is not required and that the motion compensation can be resolved with smart signal processing. For frequency-division multiplexing the transmit antennas are 15 active at the same time but at different centre frequencies.…”

High-Resolution 160-GHz Imaging MIMO Radar Using MMICs With On-Chip Frequency Synthesizers

“…This reduces the maximum detectable Doppler frequency f D,max by the number of transmit antennas because the Doppler frequency f D is only sampled by every 8th transmitted ramp [27]. Furthermore, an additional phase difference of ∆φ TDM =2πf D T r due to the switching time occurs, which is corrected by an adapted discrete Fourier transform as in [34]. The time T r denotes the ramp repetition time between two consecutive ramp segments.…”

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