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: "a generalized spatial correlation model for 3d mimo channels based on the fourier coefficients of power spectrums"
  Abstract: Previous studies have confirmed the adverse impact of fading correlation on the mutual information (MI) of two-dimensional (2D) multiple-input multiple-output (MIMO) systems. More recently, the trend is to enhance the system performance by exploiting the channels degrees of freedom in the elevation, which necessitates the derivation and characterization of three-dimensional (3D) channels in the presence of spatial correlation. In this paper, an exact closed-form expression for the Spatial Correlation Function (SCF) is derived for 3D MIMO channels. The proposed method resorts to the spherical harmonic expansion (SHE) of plane waves and the trigonometric expansion of Legendre and associated Legendre polynomials. The resulting expression depends on the underlying arbitrary angular distributions and antenna patterns through the Fourier Series (FS) coefficients of power azimuth and elevation spectrums. The novelty of the proposed method lies in the SCF being valid for any 3D propagation environment. The developed SCF determines the covariance matrices at the transmitter and the receiver that form the Kronecker channel model. In order to quantify the effects of correlation on system performance, the information-theoretic deterministic equivalents of the MI for the Kronecker model are utilized in both mono-user and multi-user cases. Numerical results validate the proposed analytical expressions and elucidate the dependence of the system performance on azimuth and elevation angular spreads and antenna patterns. Some useful insights into the behavior of MI as a function of downtilt angles are provided. The derived model will help evaluate the performance of correlated 3D MIMO channels in the future.

Connected through hyperedge HE-1 (induced by source paper "asymptotic max min sinr analysis of reconfigurable intelligent surface assisted miso systems"):
  with members:
    - "intelligent reflecting surface versus decode and forward how large surfaces are needed to beat relaying"
    - "large intelligent surface antennas lisa making reflective radios smart"
    - "asymptotic analysis of rzf over double scattering channels with mmse estimation"
    - "rfocus practical beamforming for small devices"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "enabling secure wireless communications via intelligent reflecting surfaces"
    - "enabling large intelligent surfaces with compressive sensing and deep learning"
    - "mimo assisted networks relying on large intelligent surfaces a stochastic geometry model"

Connected through hyperedge HE-2 (induced by source paper "spatial characterization of holographic mimo channels"):
  with members:
    - "degrees of freedom of holographic mimo channels"
    - "large system analysis of massive mimo with optimal m mmse processing"
    - "beyond massive mimo the potential of data transmission with large intelligent surfaces"
    - "massive mimo has unlimited capacity"
    - "optimal pilot and payload power control in single cell massive mimo systems"
    - "space constrained massive mimo hitting the wall of favorable propagation"
    - "on landau s eigenvalue theorem and information cut sets"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"

Connected through hyperedge HE-3 (induced by source paper "spatially stationary model for holographic mimo small scale fading"):
  with members:
    - "degrees of freedom of holographic mimo channels"
    - "beyond massive mimo the potential of data transmission with large intelligent surfaces"
    - "massive mimo has unlimited capacity"
    - "ns 3 implementation of the 3gpp mimo channel model for frequency spectrum above 6 ghz"
    - "optimal pilot and payload power control in single cell massive mimo systems"
    - "on landau s eigenvalue theorem and information cut sets"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-4 (induced by source paper "elevation beamforming with full dimension mimo architectures in 5g systems a tutorial"):
  with members:
    - "asymptotic analysis of rzf over double scattering channels with mmse estimation"
    - "distributed fd mimo cellular evolution for 5g and beyond"
    - "overview of full dimension mimo in lte advanced pro"
    - "an effective limited feedback scheme for fd mimo based on noncoherent detection and kronecker product codebook"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "3d channel model in 3gpp"
    - "3d massive mimo systems modeling and performance analysis"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"

Connected through hyperedge HE-5 (induced by source paper "broadbeam for massive mimo systems"):
  with members:
    - "massive mimo 10 myths and one grand question"
    - "transmit radiation pattern invariance in mimo radar with application to doa estimation"
    - "massive mimo for next generation wireless systems"
    - "preliminary results on 3d channel modeling from theory to standardization"
    - "five disruptive technology directions for 5g"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "constant envelope multi user precoding for frequency selective massive mimo systems"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"

Connected through hyperedge HE-6 (induced by source paper "design of 5g full dimension massive mimo systems"):
  with members:
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "preliminary results on 3d channel modeling from theory to standardization"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-7 (induced by source paper "3d massive mimo systems modeling and performance analysis"):
  with members:
    - "massive mimo for next generation wireless systems"
    - "preliminary results on 3d channel modeling from theory to standardization"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "comments on proakis analysis of the characteristic function of complex gaussian quadratic forms"

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)