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: "multiuser diversity for secrecy communications using opportunistic jammer selection secure dof and jammer scaling law"
  Abstract: In this paper, we propose opportunistic jammer selection in a wireless security system for increasing the secure degrees of freedom (DoF) between a transmitter and a legitimate receiver (say, Alice and Bob). There is a jammer group consisting of $S$ jammers among which Bob selects $K$ jammers. The selected jammers transmit independent and identically distributed Gaussian signals to hinder the eavesdropper (Eve). Since the channels of Bob and Eve are independent, we can select the jammers whose jamming channels are aligned at Bob, but not at Eve. As a result, Eve cannot obtain any DoF unless it has more than $KN_j$ receive antennas, where $N_j$ is the number of jammer's transmit antenna each, and hence $KN_j$ can be regarded as defensible dimensions against Eve. For the jamming signal alignment at Bob, we propose two opportunistic jammer selection schemes and find the scaling law of the required number of jammers for target secure DoF by a geometrical interpretation of the received signals.

Connected through hyperedge HE-1 (induced by source paper "effective optimization criteria and relay selection algorithms for physical layer security in multiple antenna relay networks"):
  with members:
    - "widely linear precoding for large scale mimo with iqi algorithms and performance analysis"
    - "direction finding algorithms based on joint iterative subspace optimization"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "buffer aided relaying with adaptive link selection fixed and mixed rate transmission"
    - "adaptive distributed space time coding based on adjustable code matrices for cooperative mimo relaying systems"
    - "joint relay and jammer selection for secure two way relay networks"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "collaborative relay beamforming for secrecy"

Connected through hyperedge HE-2 (induced by source paper "mimo secret communications against an active eavesdropper"):
  with members:
    - "secure degrees of freedom regions of multiple access and interference channels the polytope structure"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "improving wireless physical layer security via exploiting co channel interference"
    - "secure massive mimo transmission with an active eavesdropper"
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "secure massive mimo transmission in the presence of an active eavesdropper"
    - "secure degrees of freedom of one hop wireless networks"
    - "improving physical layer secrecy using full duplex jamming receivers"

Connected through hyperedge HE-3 (induced by source paper "improving wireless physical layer security via exploiting co channel interference"):
  with members:
    - "joint power control in wiretap interference channels"
    - "secrecy transmit beamforming for heterogeneous networks"
    - "improving physical layer secrecy using full duplex jamming receivers"
    - "mobile jammers for secrecy rate maximization in cooperative networks"
    - "secure degrees of freedom of k user gaussian interference channels a unified view"
    - "mimo interference alignment over correlated channels with imperfect csi"
    - "interference alignment for secrecy"
    - "on cooperative relaying schemes for wireless physical layer security"

Connected through hyperedge HE-4 (induced by source paper "secure communication in uplink transmissions user selection and multiuser secrecy gain"):
  with members:
    - "secure massive mimo transmission with an active eavesdropper"
    - "the ergodic capacity of the multiple access channel under distributed scheduling order optimality of linear receivers"
    - "exact joint distribution analysis of zero forcing v blast gains with greedy ordering"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "secure diversity multiplexing tradeoff of zero forcing transmit scheme at finite snr"
    - "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"
    - "on the secure degrees of freedom of the multiple access channel"

Connected through hyperedge HE-5 (induced by source paper "study of tomlinson harashima precoding strategies for physical layer security in wireless networks"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "buffer aided relaying with adaptive link selection fixed and mixed rate transmission"
    - "adaptive distributed space time coding based on adjustable code matrices for cooperative mimo relaying systems"
    - "joint relay and jammer selection for secure two way relay networks"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "collaborative relay beamforming for secrecy"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-6 (induced by source paper "study of relay selection for physical layer security in buffer aided relay networks based on the secrecy rate criterion"):
  with members:
    - "multi branch tomlinson harashima precoding design for mu mimo systems theory and algorithms"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "buffer aided relaying with adaptive link selection fixed and mixed rate transmission"

Connected through hyperedge HE-7 (induced by source paper "on secrecy rates and outage in multi user multi eavesdroppers miso systems"):
  with members:
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-8 (induced by source paper "study of opportunistic cooperation techniques using jamming and relays for physical layer security in buffer aided relay networks"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "buffer aided relaying with adaptive link selection fixed and mixed rate transmission"
    - "adaptive distributed space time coding based on adjustable code matrices for cooperative mimo relaying systems"
    - "joint relay and jammer selection for secure two way relay networks"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "collaborative relay beamforming for secrecy"
    - "the secrecy capacity of the mimo wiretap channel"

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)