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: "linear precoding for broadcast channels with confidential messages under transmit side channel correlation"
  Abstract: In this paper, we analyze the performance of regularized channel inversion (RCI) precoding in multiple-input single-output (MISO) broadcast channels with confidential messages under transmit-side channel correlation. We derive a deterministic equivalent for the achievable per-user secrecy rate which is almost surely exact as the number of transmit antennas and the number of users grow to infinity in a fixed ratio, and we determine the optimal regularization parameter that maximizes the deterministic equivalent of the secrecy rate. Furthermore, we obtain deterministic equivalents for the secrecy rates achievable by: (i) zero forcing precoding and (ii) single user beamforming. The accuracy of our analysis is validated by simulations of finite-size systems.

Connected through hyperedge HE-1 (induced by source paper "secure regularized zero forcing for multiuser mimome channels"):
  with members:
    - "on robustness of massive mimo systems against passive eavesdropping under antenna selection"
    - "glse precoders for massive mimo systems analysis and applications"
    - "nonlinear precoders for massive mimo systems with general constraints"
    - "asymptotics of nonlinear lse precoders with applications to transmit antenna selection"
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "applications of large random matrices in communications engineering"
    - "large system analysis of linear precoding in miso broadcast channels with confidential messages"
    - "secrecy sum rates for multi user mimo regularized channel inversion precoding"

Connected through hyperedge HE-2 (induced by source paper "cell edge aware precoding for downlink massive mimo cellular networks"):
  with members:
    - "distributed optimization of hierarchical small cell networks a gnep framework"
    - "massive mimo ten myths and one critical question"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "energy efficient design of mimo heterogeneous networks with wireless backhaul"
    - "a stochastic geometry framework for analyzing pairwise cooperative cellular networks"
    - "three practical aspects of massive mimo intermittent user activity pilot synchronism and asymmetric deployment"
    - "fractional pilot reuse in massive mimo systems"
    - "a tractable model for noncoherent joint transmission base station cooperation"

Connected through hyperedge HE-3 (induced by source paper "energy efficient design of mimo heterogeneous networks with wireless backhaul"):
  with members:
    - "energy efficiency of distributed signal processing in wireless networks a cross layer analysis"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "interference management in 5g reverse tdd hetnets with wireless backhaul a large system analysis"
    - "5g wireless backhaul networks challenges and research advances"
    - "wireless backhaul networks capacity bound scalability analysis and design guidelines"
    - "tractable model for rate in self backhauled millimeter wave cellular networks"
    - "joint rate and sinr coverage analysis for decoupled uplink downlink biased cell associations in hetnets"
    - "physical layer security in downlink multi antenna cellular networks"

Connected through hyperedge HE-4 (induced by source paper "physical layer security in downlink multi antenna cellular networks"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "secrecy rates in the broadcast channel with confidential messages and external eavesdroppers"
    - "on the optimality of linear precoding for secrecy in the mimo broadcast channel"
    - "downlink mimo hetnets modeling ordering results and performance analysis"
    - "new results on multiple input multiple output broadcast channels with confidential messages"
    - "large system analysis of linear precoding in miso broadcast channels with confidential messages"
    - "physical layer security in cellular networks a stochastic geometry approach"
    - "secrecy sum rates for multi user mimo regularized channel inversion precoding"

Connected through hyperedge HE-5 (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"
    - "secrecy sum rates with regularized channel inversion precoding under imperfect csi at the transmitter"
    - "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-6 (induced by source paper "secrecy rates in the broadcast channel with confidential messages and external eavesdroppers"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "on the optimality of linear precoding for secrecy in the mimo broadcast channel"
    - "new results on multiple input multiple output broadcast channels with confidential messages"
    - "large system analysis of linear precoding in miso broadcast channels with confidential messages"
    - "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"
    - "secrecy degrees of freedom of mimo broadcast channels with delayed csit"
    - "the secrecy graph and some of its properties"

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)