Chameleon: Integrated Sensing and Communication with Sub-Symbol Beam Switching in mmWave Networks

Future cellular networks aim to integrate sensing with communication, leveraging beamforming in the millimeter wave (mmWave) band for its enhanced spatial multiplexing. In this paper, we present CHAMELEON, a novel framework that augments and rapidly switches beamformers during each demodulation reference signal (DMRS) symbol to achieve integrated sensing and communication (ISAC) in 5G mmWave networks. Each beamformer introduces an additional sensing beam toward target angles while maintaining the communication beams toward multiple users. We deploy CHAMELEON on a 28 GHz software-defined radio testbed. For two users, CHAMELEON achieves a sweeping sensing beam with a beamforming gain of 20.52–21.69 dB, while incurring only a 0.63–4.60 dB degradation in the communication beams. In dynamic scenarios, a single-core server can support up to 14 real-time beamformer updates.