Enhanced Sensing for Automotive mmWave Radar: Super-Resolution Range and Angle Estimation With Coherent Extension and Advanced IAA

This article delves into the super-resolution problem of range and angle for millimeter wave (mmWave) frequency-modulated continuous wave radar. First, a modified diagonal loading (MDL) is proposed for range estimation in practical scenarios to improve the convergence of the iterative adaptive approach (IAA). This loading term can be flexibly adjusted according to the actual noise level, and it has the potential to surpass the existing adaptive diagonal loading IAA under low signal-to-noise ratio. Second, the range estimation results are used for signal enhancement. A coherent extension technique is adopted to address the phase discontinuity between adjacent chirps, thus enabling the construction of a longer chirp signal. Finally, the extended signal is used to generate a super-resolution range-angle map. Practical and numerical examples demonstrate the feasibility of the above methodology.