Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: MIMO Detection for Reconfigurable Intelligent Surface-Assisted
  Millimeter Wave Systems   Millimeter wave (mmWave) band, or high frequencies such as THz, has large
undeveloped band of spectrum. However, wireless channels over the mmWave band
usually have one or two paths only due to the severe attenuation. The channel
property restricts its development in the multiple-input multiple-output (MIMO)
system, which can improve throughput by increasing the spectral efficiency.
Recent development in reconfigurable intelligent surface (RIS) provides new
opportunities to mmWave communications. In this study, we propose a mmWave
system, which used low-precision analog-to-digital converters (ADCs), with the
aid of several RIS arrays. Moreover, each RIS array has many reflectors with
discrete phase shift. By employing the linear spatial processing, these arrays
form a synthetic channel with increased spatial diversity and power gain, which
can support MIMO transmission. We develop a MIMO detector according to the
characteristics of the synthetic channel. RIS arrays can provide spatial
diversity to support MIMO transmission, however, different number, antenna
configuration, and deployment of RIS arrays affect the bit error rate (BER)
performance. We present state evolution (SE) equations to evaluate the BER of
the proposed MIMO detector in the different cases. The BER performance of
indoor system is studied extensively through leveraging by the SE equations. We
reveal numerous insights about the RIS effects and discuss the appropriate
system settings. In addition, our results demonstrate that the low-cost
hardware, such as the 3-bit ADCs of the receiver side and the 2-bit uniform
discrete phase shift of the RIS arrays, only moderately degenerate the system
performance.

15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
26
The categories of this paper are: bayes-an
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin