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: "performance analysis for physical layer security in multi antenna downlink networks with limited csi feedback"
  Abstract: Channel state information (CSI) at the transmitter is of importance to the performance of physical layer security based on multi-antenna networks. Specifically, CSI is not only beneficial to improve the capacity of the legitimate channel, but also can be used to degrade the performance of the eavesdropper channel. Thus, the secrecy rate increases accordingly. This letter focuses on the quantitative analysis of the ergodic secrecy sum-rate in terms of feedback amount of the CSI from the legitimate users in multiuser multi-antenna downlink networks. Furthermore, the asymptotic characteristics of the ergodic secrecy sum-rate in two extreme cases is investigated in some detail. Finally, our theoretical claims are confirmed by the numerical results.

Connected through hyperedge HE-1 (induced by source paper "secrecy analysis of random mimo wireless networks over alpha mu fading channels"):
  with members:
    - "on secrecy performance of antenna selection aided mimo systems against eavesdropping"
    - "physical layer security in millimeter wave cellular networks"
    - "the secrecy graph and some of its properties"
    - "a geometric interpretation of fading in wireless networks theory and applications"

Connected through hyperedge HE-2 (induced by source paper "on interference alignment with imperfect csi characterizations of outage probability ergodic rate and ser"):
  with members:
    - "performance analysis and optimization for interference alignment over mimo interference channels with limited feedback"
    - "the feasibility conditions for interference alignment in mimo networks"
    - "on the achievable dof and user scaling law of opportunistic interference alignment in 3 transmitter mimo interference channels"
    - "interference aware resource control in multi antenna cognitive ad hoc networks with heterogeneous delay constraints"
    - "limited feedback design for interference alignment on mimo interference networks with heterogeneous path loss and spatial correlations"
    - "opportunistic interference alignment for mimo interfering multiple access channels"
    - "on the degrees of freedom achievable through interference alignment in a mimo interference channel"
    - "distributed robust multicell coordinated beamforming with imperfect csi an admm approach"

Connected through hyperedge HE-3 (induced by source paper "secrecy wireless information and power transfer challenges and opportunities"):
  with members:
    - "physical layer security in three tier wireless sensor networks a stochastic geometry approach"
    - "secure massive mimo transmission with an active eavesdropper"
    - "large scale mimo relaying techniques for physical layer security af or df"
    - "multi antenna relay aided wireless physical layer security"
    - "enhancing wireless information and power transfer by exploiting multi antenna techniques"
    - "optimal power allocation for a massive mimo relay aided secure communication"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "secure and green swipt in distributed antenna networks with limited backhaul capacity"

Connected through hyperedge HE-4 (induced by source paper "large scale mimo relaying techniques for physical layer security af or df"):
  with members:
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "multi antenna relay aided wireless physical layer security"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "on the secrecy outage capacity of physical layer security in large scale mimo relaying systems with imperfect csi"
    - "exploiting large scale mimo techniques for physical layer security with imperfect channel state information"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "large system analysis of linear precoding in miso broadcast channels with confidential messages"

Connected through hyperedge HE-5 (induced by source paper "mode selection in mu mimo downlink networks a physical layer security perspective"):
  with members:
    - "energy efficient power allocation for secure communications in large scale mimo relaying systems"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "energy efficient optimization for physical layer security in multi antenna downlink networks with qos guarantee"
    - "multi mode transmission for the mimo broadcast channel with imperfect channel state information"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "the secrecy capacity region of the gaussian mimo multi receiver wiretap channel"
    - "achieving near capacity at low snr on a multiple antenna multiple user channel"

Connected through hyperedge HE-6 (induced by source paper "optimal power allocation for secure communications in large scale mimo relaying systems"):
  with members:
    - "on the secrecy outage capacity of physical layer security in large scale mimo relaying systems with imperfect csi"
    - "cooperative jamming for secure communications in mimo relay networks"

Connected through hyperedge HE-7 (induced by source paper "energy efficient power allocation for secure communications in large scale mimo relaying systems"):
  with members:
    - "on the secrecy outage capacity of physical layer security in large scale mimo relaying systems with imperfect csi"
    - "energy efficient joint source and channel sensing in cognitive radio sensor networks"
    - "secure beamforming for mimo two way communications with an untrusted relay"
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "large system analysis of linear precoding in miso broadcast channels with confidential messages"
    - "energy efficient optimization for physical layer security in multi antenna downlink networks with qos guarantee"
    - "cooperative jamming for secure communications in mimo relay networks"

Connected through hyperedge HE-8 (induced by source paper "on the secrecy outage capacity of physical layer security in large scale mimo relaying systems with imperfect csi"):
  with members:
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "energy efficient optimization for physical layer security in multi antenna downlink networks with qos guarantee"
    - "relay placement for physical layer security a secure connection perspective"
    - "on cooperative relaying schemes for wireless physical layer security"
    - "cooperative jamming for secure communications in mimo relay networks"

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)