OpenISAC: An Open-Source Real-Time Experimentation Platform for OFDM-ISAC with Over-the-Air Synchronization
Zhiwen Zhou, Chaoyue Zhang, Xiaoli Xu, Yong Zeng
TL;DR
OpenISAC tackles the lack of accessible, real-time ISAC testbeds by delivering an open-source platform that combines CW OFDM sensing with real-time communication on USRPs. Its key innovation, over-the-air synchronization, enables robust bistatic and multistatic sensing without wired links, while the hybrid C++/Python stack provides both high-performance processing and approachable prototyping. The paper demonstrates comprehensive signal-processing chains for monostatic and bistatic OFDM-ISAC, including clutter suppression, delay-Doppler and micro-Doppler extraction, and OTA timing alignment validated through real experiments with UAV targets. The results show real-time performance and high-fidelity sensing, underscoring the platform’s potential to accelerate ISAC research and facilitate broader adoption in academia and industry.
Abstract
Integrated sensing and communication (ISAC) is envisioned to be one of the key usage scenarios for the sixth generation (6G) mobile communication networks. While significant progresses have been achieved for the theoretical studies, the further advancement of ISAC is hampered by the lack of accessible, open-source, and real-time experimental platforms. To address this gap, we introduce OpenISAC, a versatile and high-performance open-source platform for real-time ISAC experimentation. OpenISAC utilizes orthogonal frequency division multiplexing (OFDM) waveform and implements crucial sensing functionalities, including both monostatic and bistatic delay-Doppler sensing. A key feature of our platform is a novel over-the-air (OTA) synchronization mechanism that enables robust bistatic operations without requiring a wired connection between nodes. The platform is built entirely on open-source software, leveraging the universal software radio peripheral (USRP) hardware driver (UHD) library, thus eliminating the need for any commercial licenses. It supports a wide range of software-defined radios, from the cost-effective USRP B200 series to the high-performance X400 series. The physical layer modulator and demodulator are implemented with C++ for high-speed processing, while the sensing data is streamed to a Python environment, providing a user-friendly interface for rapid prototyping and validation of sensing signal processing algorithms. With flexible parameter selection and real-time communication and sensing operation, OpenISAC serves as a powerful and accessible tool for the academic and research communities to explore and innovate within the field of OFDM-ISAC.