human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "secrecy sum rates with regularized channel inversion precoding under imperfect csi at the transmitter"
  Abstract: In this paper, we study the performance of regularized channel inversion precoding in MISO broadcast channels with confidential messages under imperfect channel state information at the transmitter (CSIT). We obtain an approximation for the achievable secrecy sum-rate which is almost surely exact as the number of transmit antennas and the number of users grow to infinity in a fixed ratio. Simulations prove this anaylsis accurate even for finite-size systems. For FDD systems, we determine how the CSIT error must scale with the SNR, and we derive the number of feedback bits required to ensure a constant high-SNR rate gap to the case with perfect CSIT. For TDD systems, we study the optimum amount of channel training that maximizes the high-SNR secrecy sum-rate.

Connected through hyperedge HE-1 (induced by source paper "large system analysis of linear precoding in miso broadcast channels with confidential messages"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "linear precoding for broadcast channels with confidential messages under transmit side channel correlation"
    - "secrecy sum rates for multi user mimo regularized channel inversion precoding"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"
    - "rethinking the secrecy outage formulation a secure transmission design perspective"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "secure transmission with artificial noise over fading channels achievable rate and optimal power allocation"
    - "eigen based transceivers for the mimo broadcast channel with semi orthogonal user selection"

Connected through hyperedge HE-2 (induced by source paper "wireless physical layer security with imperfect channel state information a survey"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "on the design of artificial noise aided secure multi antenna transmission in slow fading channels"
    - "robust secure transmission in miso channels based on worst case optimization"
    - "optimal and robust transmit designs for miso channel secrecy by semidefinite programming"
    - "rethinking the secrecy outage formulation a secure transmission design perspective"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "on the throughput cost of physical layer security in decentralized wireless networks"
    - "secure transmission with artificial noise over fading channels achievable rate and optimal power allocation"

Question: Please tell me which class the center node 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)