human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "power allocation and time domain artificial noise design for wiretap ofdm with discrete inputs"):
  Abstract: Optimal power allocation for orthogonal frequency division multiplexing (OFDM) wiretap channels with Gaussian channel inputs has already been studied in some previous works from an information theoretical viewpoint. However, these results are not sufficient for practical system designs. One reason is that discrete channel inputs, such as quadrature amplitude modulation (QAM) signals, instead of Gaussian channel inputs, are deployed in current practical wireless systems to maintain moderate peak transmission power and receiver complexity. In this paper, we investigate the power allocation and artificial noise design for OFDM wiretap channels with discrete channel inputs. We first prove that the secrecy rate function for discrete channel inputs is nonconcave with respect to the transmission power. To resolve the corresponding nonconvex secrecy rate maximization problem, we develop a low-complexity power allocation algorithm, which yields a duality gap diminishing in the order of O(1/√N), where N is the number of subcarriers of OFDM. We then show that independent frequency-domain artificial noise cannot improve the secrecy rate of single-antenna wiretap channels. Towards this end, we propose a novel time-domain artificial noise design which exploits temporal degrees of freedom provided by the cyclic prefix of OFDM systems to jam the eavesdropper and boost the secrecy rate even with a single antenna at the transmitter. Numerical results are provided to illustrate the performance of the proposed design schemes.

Includes members:
  Member "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "rethinking secure precoding via interference exploitation a smart eavesdropper perspective")
  Member "mimo multiple access channel with an arbitrarily varying eavesdropper":
    also connected through other hyperedges:
      (none)
  Member "optimal and robust transmit designs for miso channel secrecy by semidefinite programming":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "noma an information theoretic perspective")
  Member "solutions for the mimo gaussian wiretap channel with a cooperative jammer":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "multi antenna jamming in covert communication")
  Member "estimation in gaussian noise properties of the minimum mean square error":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "compressed coding amp based decoding and analog spatial coupling")
  Member "secrecy capacity of the gaussian wire tap channel with finite complex constellation input":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "mimo df relay beamforming for secrecy with artificial noise imperfect csi and finite alphabet")
  Member "secure transmission with multiple antennas ii the mimome wiretap channel":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "multi antenna jamming in covert communication")
  Member "the wiretap channel with feedback encryption over the channel":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "a survey of physical layer security techniques for 5g wireless networks and challenges ahead")

Question: Please tell me which class the source paper belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.IT(Information Theory)