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: "uplink performance of large optimum combining antenna arrays in poisson cell networks"
  Abstract: The uplink of a wireless network with base stations distributed according to a Poisson Point Process (PPP) is analyzed. The base stations are assumed to have a large number of antennas and use linear minimum-mean-square-error (MMSE) spatial processing for multiple access. The number of active mobiles per cell is limited to permit channel estimation using pilot sequences that are orthogonal in each cell. The cumulative distribution function (CDF) of a randomly located link in a typical cell of such a system is derived when accurate channel estimation is available. A simple bound is provided for the spectral efficiency when channel estimates suffer from pilot contamination. The results provide insight into the performance of so-called massive Multiple-Input-Multiple-Output (MIMO) systems in spatially distributed cellular networks.

Connected through hyperedge HE-1 (induced by source paper "stochastic geometry based uplink analysis of massive mimo systems with fractional pilot reuse"):
  with members:
    - "johnson mehl cell based analysis of ul cellular network with coupled user and bs locations"
    - "fog massive mimo a user centric seamless hot spot architecture"
    - "massive mimo has unlimited capacity"
    - "modeling and analysis of cellular networks using stochastic geometry a tutorial"
    - "a primer on cellular network analysis using stochastic geometry"
    - "user point processes in cellular networks"
    - "poisson hole process theory and applications to wireless networks"
    - "massive mimo enabled full duplex cellular networks"

Connected through hyperedge HE-2 (induced by source paper "uplink performance of large optimum combining antenna arrays in power controlled cellular networks"):
  with members:
    - "massive mimo for next generation wireless systems"
    - "asymptotic spectral efficiency of the uplink in spatially distributed wireless networks with multi antenna base stations"
    - "asymptotic data rates of receive diversity systems with mmse estimation and spatially correlated interferers"
    - "analytical modeling of uplink cellular networks"
    - "cellular systems with many antennas large system analysis under pilot contamination"

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)