Millimeter-wave (mmWave) multiple-input multiple-output (MIMO) system for the
fifth generation (5G) cellular communications can also enable single-anchor
positioning and object tracking due to its large bandwidth and inherently high
angular resolution. In this paper, we introduce the newly invented concept,
large intelligent surface (LIS), to mmWave positioning systems, study the
theoretical performance bounds (i.e., Cram\'er-Rao lower bounds) for
positioning, and evaluate the impact of the number of LIS elements and the
value of phase shifters on the position estimation accuracy compared to the
conventional scheme with one direct link and one non-line-of-sight path. It is
verified that better performance can be achieved with a LIS from the
theoretical analyses and numerical study.

本篇文章介绍了大型智能表面（LIS）在毫米波（mmWave）定位系统中的原理和性能，研究了与传统方案的比较，并验证了理论分析和数值研究所预测的更好性能。

毫米波 MIMO 系统中的大型智能表面定位

Large Intelligent Surface for Positioning in Millimeter Wave MIMO  Systems

Large intelligent surface (LIS)-assisted wireless communications have drawn
attention worldwide. With the use of low-cost LIS on building walls, signals
can be reflected by the LIS and sent out along desired directions by
controlling its phases, thereby providing supplementary links for wireless
communication systems. In this study, we evaluate the performance of an
LIS-assisted large-scale antenna system by formulating a tight approximation of
the ergodic capacity and investigate the effect of the phase shifts on the
ergodic capacity in different propagation scenarios. In particular, we propose
an optimal phase shift design based on the ergodic capacity approximation and
statistical channel state information. Furthermore, we derive the requirement
on the quantization bits of the LIS to promise an acceptable capacity
degradation. Numerical results show that using the proposed phase shift design
can achieve the maximum ergodic capacity, and a 2-bit quantizer is sufficient
to ensure capacity degradation of no more than 1 bit/s/Hz.

本研究提出了一种基于相位偏移的最优设计方案，通过量化 LIS 来保证通信质量，在不同的传播场景下评估了大规模天线系统的性能

利用统计 CSI 的大型智能表面辅助无线通信

Large Intelligent Surface-Assisted Wireless Communication Exploiting  Statistical CSI

In this paper, we consider the potential of data-transmission in a system
with a massive number of radiating and sensing elements, thought of as a
contiguous surface of electromagnetically active material. We refer to this as
a large intelligent surface (LIS). The "LIS" is a newly proposed concept, which
conceptually goes beyond contemporary massive MIMO technology, that arises from
our vision of a future where man-made structures are electronically active with
integrated electronics and wireless communication making the entire environment
"intelligent".
We consider capacities of single-antenna autonomous terminals communicating
to the LIS where the entire surface is used as a receiving antenna array. Under
the condition that the surface-area is sufficiently large, the received signal
after a matched-filtering (MF) operation can be closely approximated by a
sinc-function-like intersymbol interference (ISI) channel. We analyze the
capacity per square meter (m^2) deployed surface, \hat{C}, that is achievable
for a fixed transmit power per volume-unit, \hat{P}. Moreover, we also show
that the number of independent signal dimensions per m deployed surface is
2/\lambda for one-dimensional terminal-deployment, and \pi/\lambda^2 per m^2
for two and three dimensional terminal-deployments. Lastly, we consider
implementations of the LIS in the form of a grid of conventional antenna
elements and show that, the sampling lattice that minimizes the surface-area of
the LIS and simultaneously obtains one signal space dimension for every spent
antenna is the hexagonal lattice. We extensively discuss the design of the
state-of-the-art low-complexity channel shortening (CS) demodulator for
data-transmission with the LIS.

本文提出了一种大面积智能面（LIS）的概念，通过匹配滤波操作，研究单天线终端与 LIS 的容量和最佳抽样格点。同时，设计了用于数据传输的低复杂度通道缩短解调器。