FMCW-Based Integrated Sensing and Communication System: Design, Implementation, and Experimental Measurements

This study proposes a radar-centric integrated sensing and communication (ISAC) system that utilizes a two-layer modulation scheme for vehicular networks. Frequencymodulated continuous wave (FMCW) chirps are jointly modulated via phase modulation (PM) and index modulation (IM) to transmit data while maintaining sensing as the primary function. Moreover, a novel radar signal processing technique is developed to mitigate the impacts of IM and PM on sensing accuracy, alongside a communication receiver architecture designed to demodulate IM and PM data within FMCW chirps successfully. System performance is evaluated through simulations in the 2.4 GHz and 24 GHz bands under Doppler effects, achieving communication throughputs of 25 Mbps and 50 Mbps, respectively. Furthermore, a proof-of-concept hardware implementation is realized, and experimental measurements are performed via a loopback cable to verify the feasibility of the architecture. Finally, it evaluates the fundamental trade-off between communication throughput, sensing accuracy, and out-of-band emission, demonstrating the system’s flexibility to dynamically adjust waveform parameters to meet various operational requirements.