OFDM Based Joint Communications and Human Activity Monitoring with GNU Radio

This paper implements an orthogonal frequency-division multiplexing (OFDM) based system for joint communications and sensing. A sub-5 GHz software defined radio testbed is used to demonstrate communications aided sensing in a monostatic configuration. In traditional OFDM communication processing, channel state information (CSI) is estimated and corrected to decode modulated messages. This time-varying CSI contains Doppler information from human movements in the environment. The CSI can be analyzed via time-frequency analysis to reveal human micro-Doppler signatures. Utilizing the CSI to deduce information about human movements in the environment, in addition to processing the communication payload, can increase versatility of future generation wireless systems.