Range-Velocity Estimation Assisted by Delay-Doppler Domain for B5G/6G ISAC

Integrated sensing and communication (ISAC) is emerging as a pivotal development direction for beyond-5G (B5G) and sixth-generation (6G) wireless networks, especially with the challenge of achieving the communication and sensing capabilities necessary for the future Internet of Things (IoT) paradigm under resource constraints. In this paper, we propose a joint explicit communication and implicit sensing (JECIS) system designed to generate sensing and communication signals across two distinct domains, thereby enabling the multiplexing of the same time and frequency resources. The proposed system generates a block-shaped sensing reference signal in the delay-Doppler domain to facilitate the estimation of relative range and velocity between the transmitter and the receiver, while communication signals are produced in the time-frequency domain. Furthermore, we introduce a two-step algorithm for range and velocity estimation that achieves high precision while ensuring exceptional noise resilience and low complexity. The simulation results indicate that the proposed method effectively achieves high sensing performance while the sensing signal operates at a significantly lower power level in comparison to communication signals, rendering the impact on the bit error rate (BER) of communications negligible.