Range and Velocity Estimation in Carrier-Aggregation OFDM ISAC Systems

The requirements for high-accuracy sensing in future communication systems and the similarity between communication and sensing systems have given rise to integrated sensing and communication (ISAC). Orthogonal frequency division multiplexing (OFDM) waveform has been widely considered a suitable waveform for ISAC to provide sensing functionality with little change on the existing communication systems. However, the large bandwidth requirements of high-precision sensing are contradictory to the fragmentation of communication spectrum resources. Based on existing carrier aggregation (CA) communication architecture, this paper considers a multi-band ISAC system and proposes a universal sensing signal processing algorithm for a CA-OFDM communication system. Improved IDFT and DFT factors are proposed to construct a joint multiband matching filter for CA ranging and velocity estimation. Finally, simulation results confirm the superiority of the proposed algorithm over state-of-the-art schemes.