Experimental Demonstration of ISAC Waveform Design Exploring Out-of-Band Emission

Integrated Sensing and Communication (ISAC) is recognised as one of the key enabling technologies of the upcoming sixth generation (6G) wireless network. The last research frontier of ISAC systems is the transmission of a single waveform through a completely shared hardware platform and an optimized frequency/time/space resources allocation that tunes the trade-off between the intended communication and sensing requirements. In this paper, we dwell on the experimental demonstration of the benefits of an ISAC waveform scheme that superposes onto the frequency-time domain both the legacy orthogonal frequency division multiplexing (OFDM) and a sensing signal that exploit Out-Of-Band (OOB) emission. This latter can be designed both with classical frequency-time chirp and with a delay-Doppler impulse. The experiments' results show that the tested ISAC codesign is capable of accurately scanning and mapping an indoor environment and estimating the tangential speed of the moving targets. Moreover, we demonstrate that the interference of the superimposed sensing signal at the communication receiver is low enough that the impact on the communication performance is imperceptible.