In-Band-Full-Duplex Integrated Sensing and Communications for IAB Networks

In this paper, we develop an in-band-full-duplex (IBFD)-integrated sensing and communications (ISAC)-integrated access backhaul (IAB) network operating at frequency range 2 (FR2) for vehicle-to-everything (V2X) communications, where the IAB-node acts as a roadside unit (RSU) performing communication simultaneously (i.e., same time band). Self-interference (SI) due to IBFD operation can be canceled in propagation, analog, digital domains; only residual SI (RSI) is reserved performance analysis. Unscented Kalman filter (UKF) used tracking multiple vehicles studied scenario. Considering subarray-based hybrid beamforming structure, including hardware impairments (HWI) RF effective channel estimation error, with sufficient cancellation, simulations show that UKF give satisfactory radar accuracy. The resulting mean-squared errors averaged across all of each state parameter are close their posterior Cramér-Rao lower bounds. Compared half-duplex-ISAC-IAB networks, IBFD-ISAC-IAB networks nearly double spectral efficiency both links. Moreover, less error is, higher link is.