A Novel Hybrid TDMA–DDMA Approach for Imaging Automotive Radar Systems

In this letter, we propose a novel hybrid time-division multiple access (TDMA) and Doppler-division multiple access (DDMA) model for cascaded radar systems, targeting high-resolution automotive radar applications. By leveraging the Texas instruments AWR2243 radar sensor, configured in a cascaded multiple-input multiple-output arrangement, we demonstrate the advantages of combining TDMA and DDMA for enhanced performance in both velocity resolution and range accuracy. Conventional TDMA and DDMA approaches suffer from inherent tradeoffs between maximum unambiguous velocity, Doppler resolution, and frame rate. Our hybrid method dynamically toggle between TDMA and DDMA activation patterns, achieving a balance between these metrics. Through theoretical analysis and experimental validation, we show that our model improves Doppler resolution while maintaining a competitive frame rate and range resolution. The proposed hybrid solution is particularly advantageous for scenarios where both high velocity measurements and high angular resolution are critical, such as in advanced driver-assistance systems and autonomous driving. This approach provides a flexible and efficient means of optimizing radar performance without compromising key system parameters, as supported by our experimental results and theoretical calculations.