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: "spatial characterization of holographic mimo channels"
  Abstract: Imagine beings surrounded by continuous apertures that can emit and receive electromagnetic waves. A system of this sort, having an uncountably infinite number of antennas in a compact space, is called Holographic MIMO. Given the solid results for Massive MIMO, one might expect a holographic system to realize extreme spatial resolution, incredible energy efficiency, and unprecedented spectral efficiency. At present, however, the fundamental advantages of continuous apertures over conventional discrete spaced antenna arrays have not been conclusively established. A major challenge for the analysis and understanding of such a paradigm shift is the lack of mathematically tractable and numerically reproducible spatially-continuous channel models that retain some semblance of the physical reality. Physical models are too complex for tractable analysis. This paper aims to take a closer look at this challenge through the conventional tools of linear systems theory and Fourier transform. Notably, this leads to a rather simple Fourier plane-wave spectral representation of a three-dimensional spatially-continuous channel from which a computationally efficient way to generate samples over compact continuous apertures can be developed.

Connected through hyperedge HE-1 (induced by source paper "holographic mimo surfaces for 6g wireless networks opportunities challenges and trends"):
  with members:
    - "enabling large intelligent surfaces with compressive sensing and deep learning"
    - "dynamic metasurface antennas for uplink massive mimo systems"
    - "towards smart and reconfigurable environment intelligent reflecting surface aided wireless network"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"
    - "beyond massive mimo the potential of positioning with large intelligent surfaces"
    - "reconfigurable intelligent surfaces for energy efficiency in wireless communication"
    - "large intelligent surface assisted wireless communication exploiting statistical csi"

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)