  The concept of large intelligent surface (LIS)-based communication has
recently raised research attention, in which a LIS is regarded as an antenna
array whose entire surface area can be used for radio signal transmission and
reception. To provide a fundamental understanding of LIS-based communication,
this paper studies the uplink (UL) performance of LIS-based communication with
matched filtering. We first investigate the new properties introduced by LIS.
In particular, the array gain, spatial resolution, and the capability of
interference suppression are theoretically presented and characterized. Then,
we study two possible LIS system layouts in terms of UL, i.e., centralized LIS
(C-LIS) and distributed LIS (D-LIS). Our analysis showcases that a centralized
system has strong capability of interference suppression; in fact, interference
can nearly be eliminated if the surface area is sufficient large or the
frequency band is sufficient high. For D-LIS, we propose a series of resource
allocation algorithms, including user association scheme, orientation control,
and power control, to extend the coverage area of a distributed system.
Simulation results show that the proposed algorithms significantly improve the
system performance, and even more importantly, we observe that D-LIS
outperforms CLIS in microwave bands, while C-LIS is superior to D-LIS in mmWave
bands. These observations serve as useful guidelines for practical LIS
deployments.
