With every new wireless generation, researchers explore new applications that can expand a network’s functionality. Recently, Integrated Sensing and Communications (ISAC) has become a hotbed of 6G research. Just last year, the European Technology Standards Institute (ETSI) launched a dedicated standards group to coordinate the pre-standards research in the area. With ISAC enabled, future 6G networks could simultaneously act as an eMBB network and radar system, unlocking new functionalities such as object and gesture detection.
At the recent Brooklyn 6G Summit, hosted by New York University, Keysight demonstrated an OFDM ISAC testbed that will allow 6G researchers to begin development of sensing algorithms before their 6G hardware is available. This early testbed will also allow researchers to incorporate sensing capabilities into the various 5G and 6G candidate waveforms in discussion.
In this demonstration, Keysight is showing results of the OFDM radar process on several potential 6G sensing use cases, including:
- People walking
- Drone detection
- ML-based gesture recognition
- Vibration frequency sensing
The demonstration uses OFDM waveforms generated with Keysight’s Signal Studio for Custom Modulation software and Keysight’s 89600 Vector Signal Analysis software, with additional processing in Keysight’s Test Automation Platform to provide sensing results from communications waveforms. Signals can be generated with various Keysight signal generators and measured with Keysight signal analyzers. For this demonstration, the signals were generated with the M9484C Vector Signal Generator and measured with the UXR-Series Oscilloscope.
The OFDM radar processing starts by dividing each received data element in the time/frequency grid by the corresponding element in the transmitted time/frequency grid. This data is generated by the demodulation process in the VSA software based on data from one acquisition. From the time result of the division of the received signal by the transmitted signal, an inverse FFT is performed along the sub-carrier axis, and then an FFT is performed along the symbol axis. These steps transform the data into axis of delay (Range) and Doppler frequency.
The transformed data allows the distance and speed of the sensing target to be detected. The VSA software supports sequenced captures allowing multiple acquisitions at specific time intervals allowing tracking of distance and speed over time.
The demonstration includes visualization of this data, using the data with additional signal processing to measure the frequency of a vibrating target, and using machine learning to recognize human gestures.
Early testbeds, like the OFDM ISAC demo, are vital to accelerating 6G research from theoretical papers to practical demonstrations. To further explore how Keysight is unlocking 6G research, read or eBook Next-Generation Wireless: A Guide to the Fundamentals of 6G.