  The Holographic Interference Surface (HIS) provides a new paradigm for
building a more cost-effective wireless communication architecture. In this
paper, we derive the principles of holographic interference theory for
electromagnetic wave reception and transmission, whereby the optical holography
is extended to communication holography and a channel sensing architecture for
holographic interference surfaces is established. Unlike the traditional
pilot-based channel estimation approaches, the proposed architecture
circumvents the complicated processes like filtering, analog to digital
conversion (ADC), down conversion. Instead, it relies on interfering the object
waves with a pre-designed reference wave, and therefore reduces the hardware
complexity and requires less time-frequency resources for channel estimation.
To address the self-interference problem in the holographic recording process,
we propose a phase shifting-based interference suppression (PSIS) method
according to the structural characteristics of communication hologram and
interference composition. We then propose a Prony-based multi-user channel
segmentation (PMCS) algorithm to acquire the channel state information (CSI).
Our theoretical analysis shows that the estimation error of the PMCS algorithm
converges to zero when the number of HIS units is large enough. Simulation
results show that under the holographic architecture, our proposed algorithm
can accurately estimate the CSI in multi-user scenarios.
