Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reconfigurable Intelligent Surface Enhanced NOMA Assisted Backscatter
  Communication System   A reconfigurable intelligent surface (RIS) enhanced non-orthogonal multiple
access assisted backscatter communication (RIS-NOMABC) system is considered. A
joint optimization problem over power reflection coefficients and phase shifts
is formulated. To solve this non-convex problem, a low complexity algorithm is
proposed by invoking the alternative optimization, successive convex
approximation and manifold optimization algorithms. Numerical results
corroborate that the proposed
  RIS-NOMABC system outperforms the conventional non-orthogonal multiple access
assisted backscatter communication (NOMABC) system without RIS, and demonstrate
the feasibility and effectiveness of the proposed algorithm.

18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
5
The categories of this paper are: gr-qc
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin