Fig. 6: Conceptual framework for the paradigm shift in channel characterization.

a Evolution of system modeling from CSI-based abstract signal-level description to MSI-based physical light field transport. b Transition from the conventional channel matrix to a channel tensor, which serves as the discrete representation of the propagation operator. c Preliminary validation of the channel tensor through high-fidelity wavefront reconstruction (including intensity and phase) based on the retrieved MSI operator.