Millimeter-Wave ISAC-ISAR Imaging System for Unknown Moving Target Sensing Using USRP

Integrated sensing and communication (ISAC) technology has garnered considerable attention in the 5G and 6G wireless communication fields. In particular, unknown moving target sensing shows significant development prospects in areas such as low-altitude security, intelligent transportation, and smart ports. However, most existing sensing methods for moving targets using communication signals are based on location and tracking, limiting the accuracy of subsequent target recognition. Inverse synthetic aperture radar (ISAR) imaging technology can obtain 2-D imaging results of moving targets and provide more fine sensing information. Inspired by this, an ISAC-ISAR imaging system is proposed for fine sensing of moving targets in the article. First, a millimeter-wave (MMW) ISAC system is established using universal software radio peripheral (USRP). Then, the ISAC-ISAR echo signal model and an imaging mechanism are introduced with static path suppression technology. Furthermore, the wavenumber-domain algorithm is proposed for fast ISAC-ISAR imaging, while the minimum entropy criterion is adopted for fine imaging of noncooperative moving targets. Finally, the ISAC-ISAR imaging experiments are conducted with USRP in the 27.95–28.05-GHz frequency range to demonstrate the performance and feasibility of the proposed system.