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: "outage probability and outage based robust beamforming for mimo interference channels with imperfect channel state information"
  Abstract: In this paper, the outage probability and outage-based beam design for multiple-input multiple-output (MIMO) interference channels are considered. First, closed-form expressions for the outage probability in MIMO interference channels are derived under the assumption of Gaussian-distributed channel state information (CSI) error, and the asymptotic behavior of the outage probability as a function of several system parameters is examined by using the Chernoff bound. It is shown that the outage probability decreases exponentially with respect to the quality of CSI measured by the inverse of the mean square error of CSI. Second, based on the derived outage probability expressions, an iterative beam design algorithm for maximizing the sum outage rate is proposed. Numerical results show that the proposed beam design algorithm yields significantly better sum outage rate performance than conventional algorithms such as interference alignment developed under the assumption of perfect CSI.

Connected through hyperedge HE-1 (induced by source paper "beamforming optimization for physical layer security in miso wireless networks"):
  with members:
    - "mimo beamforming for secure and energy efficient wireless communication"
    - "robust chance constrained optimization for power efficient and secure swipt systems"
    - "secrecy energy efficiency optimization for miso and siso communication networks"
    - "secrecy wireless information and power transfer with miso beamforming"
    - "toward energy efficient 5g wireless communications technologies"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"
    - "spatially selective artificial noise aided transmit optimization for miso multi eves secrecy rate maximization"

Connected through hyperedge HE-2 (induced by source paper "robust transceiver design based on interference alignment for multi user multi cell mimo networks with channel uncertainty"):
  with members:
    - "two stage beamformer design for massive mimo downlink by trace quotient formulation"
    - "exploiting known interference as green signal power for downlink beamforming optimization"
    - "optimal multiuser transmit beamforming a difficult problem with a simple solution structure"
    - "rethinking the role of interference in wireless networks"
    - "two tier precoding for fdd multi cell massive mimo time varying interference networks"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "grouping based interference alignment with ia cell assignment in multi cell mimo mac under limited feedback"
    - "multi cell random beamforming achievable rate and degrees of freedom region"

Connected through hyperedge HE-3 (induced by source paper "on the exact distribution of mutual information of two user mimo mac based on quotient distribution of wishart matrices"):
  with members:
    - "the application of mimo to non orthogonal multiple access"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "on the distribution of mimo mutual information an in depth painleve based characterization"
    - "random matrix model for nakagami hoyt fading"

Connected through hyperedge HE-4 (induced by source paper "multicell coordinated beamforming with rate outage constraint part i complexity analysis"):
  with members:
    - "signal processing and optimal resource allocation for the interference channel"
    - "multicell coordinated beamforming with rate outage constraint part ii efficient approximation algorithms"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"
    - "achievable outage rate regions for the miso interference channel"
    - "pareto characterization of the multicell mimo performance region with simple receivers"
    - "achieving global optimality for weighted sum rate maximization in the k user gaussian interference channel with multiple antennas"
    - "optimality properties distributed strategies and measurement based evaluation of coordinated multicell ofdma transmission"
    - "optimal beamforming in interference networks with perfect local channel information"

Connected through hyperedge HE-5 (induced by source paper "multicell coordinated beamforming with rate outage constraint part ii efficient approximation algorithms"):
  with members:
    - "signal processing and optimal resource allocation for the interference channel"
    - "multicell coordinated beamforming with rate outage constraint part i complexity analysis"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"
    - "achievable outage rate regions for the miso interference channel"
    - "distributed multicell beamforming design approaching pareto boundary with max min fairness"
    - "robust monotonic optimization framework for multicell miso systems"
    - "achieving global optimality for weighted sum rate maximization in the k user gaussian interference channel with multiple antennas"
    - "optimality properties distributed strategies and measurement based evaluation of coordinated multicell ofdma transmission"

Connected through hyperedge HE-6 (induced by source paper "achievable outage rate regions for the miso interference channel"):
  with members:
    - "efficient computation of pareto optimal beamforming vectors for the miso interference channel with successive interference cancellation"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"
    - "exchange economy in two user multiple input single output interference channels"
    - "mimo diversity in the presence of double scattering"

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)