Relaxed Multi-Tx DDM Online Calibration

TL;DR

This paper introduces a new family of DDM codes for MIMO radar systems that enable real-time calibration of phase shifters, ensuring optimal performance during operation, especially in automotive radar applications.

Contribution

It proposes a novel calibration DDM code family using odd-DDM sequences that scale to any number of transmit channels with reduced inter-Tx leakage.

Findings

Effective online calibration demonstrated on automotive radar data

Reduced inter-Tx leakage in the proposed calibration sequences

Scalable to any number of transmit channels

Abstract

In multiple-input and multiple-output (MIMO) radar systems based on Doppler-division multiplexing (DDM), phase shifters are employed in the transmit paths and require calibration strategies to maintain optimal performance all along the radar system's life cycle. In this paper, we propose a novel family of DDM codes that enable an online calibration of the phase shifters that scale realistically to any number of simultaneously activated transmit (Tx)-channels during the calibration frames. To achieve this goal we employ the previously developed odd-DDM (ODDM) sequences to design calibration DDM codes with reduced inter-Tx leakage. The proposed calibration sequence is applied to an automotive radar data set modulated with erroneous phase shifters.