Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Secure Massive RIS aided Multicast with Uncertain CSI: Energy-Efficiency
  Maximization via Accelerated First-Order Algorithms   Reconfigurable intelligent surface (RIS) has the potential to significantly
enhance the network secure transmission performance by reconfiguring the
wireless propagation environment. However, due to the passive nature of
eavesdroppers and the cascaded channel brought by the RIS, the eavesdroppers'
channel state information is imperfectly obtained at the base station. Under
the channel uncertainty, the optimal phase-shift, power allocation, and
transmission rate design for secure transmission is currently unknown due to
the difficulty of handling the probabilistic constraint with coupled variables.
To fill this gap, this paper formulates a problem of energy-efficient secure
transmission design while incorporating the probabilistic constraint. By
transforming the probabilistic constraint and decoupling the variables, the
secure energy efficiency maximization problem can be solved via alternatively
executing concave-convex procedure and semidefinite relaxation technique. To
scale the solution to massive antennas and reflecting elements scenario, an
accelerated first-order algorithm with low complexity is further
proposed.Simulation results show that the proposed accelerated first-order
algorithm achieves identical performance to the conventional method but saves
at least two orders of magnitude in computation time. Moreover, the resultant
RIS aided secure transmission significantly improves the energy efficiency
compared to baseline schemes of random phase-shift, fixed phase-shift, and RIS
ignoring CSI uncertainty.

22
The categories of this paper are: chao-dyn
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex