Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Differential Reflecting Modulation for Reconfigurable Intelligent
  Surface Based Communications   Reconfigurable intelligent surface (RIS) based communications have emerged as
a new paradigm. This letter proposes a differential reflecting modulation (DRM)
scheme for RIS based communication systems. In DRM, information bits are
jointly carried by the activation permutations of the reflecting patterns and
the phases of the transmitted signals, leading to that DRM can work without any
channel state information (CSI) at the transmitter, RIS or receiver. In other
words, DRM can release the intricate and resource-consuming channel estimation
in the transmission process. Simulation results show that the proposed DRM pays
an acceptable SNR penalty compared to non-differential modulation with coherent
detection.

23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an