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: "preliminary results on 3d channel modeling from theory to standardization"
  Abstract: Three dimensional beamforming (3D) (also elevation beamforming) is now gaining a growing interest among researchers in wireless communication. The reason can be attributed to its potential to enable a variety of strategies like sector or user specific elevation beamforming and cell-splitting. Since these techniques cannot be directly supported by current LTE releases, the 3GPP is now working on defining the required technical specifications. In particular, a large effort is currently made to get accurate 3D channel models that support the elevation dimension. This step is necessary as it will evaluate the potential of 3D and FD(Full Dimensional) beamforming techniques to benefit from the richness of real channels. This work aims at presenting the on-going 3GPP study item "Study on 3D-channel model for Elevation Beamforming and FD-MIMO studies for LTE", and positioning it with respect to previous standardization works.

Connected through hyperedge HE-1 (induced by source paper "understanding uav cellular communications from existing networks to massive mimo"):
  with members:
    - "cellular connected uav potentials challenges and promising technologies"
    - "supporting uav cellular communications through massive mimo"
    - "the essential guide to realizing 5g connected uavs with massive mimo"
    - "the sky is not the limit lte for unmanned aerial vehicles"
    - "a tutorial on uavs for wireless networks applications challenges and open problems"
    - "interference mitigation methods for unmanned aerial vehicles served by cellular networks"
    - "reshaping cellular networks for the sky the major factors and feasibility"
    - "massive mimo for communications with drone swarms"

Connected through hyperedge HE-2 (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"
    - "a generalized spatial correlation model for 3d mimo channels based on the fourier coefficients of power spectrums"

Connected through hyperedge HE-3 (induced by source paper "limited feedback channel estimation in massive mimo with non uniform directional dictionaries"):
  with members:
    - "overview of full dimension mimo in lte advanced pro"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "sparse channel estimation for massive mimo with 1 bit feedback per dimension"
    - "compressed sensing for wireless communications useful tips and tricks"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"
    - "achievable rates of fdd massive mimo systems with spatial channel correlation"
    - "noncoherent trellis coded quantization a practical limited feedback technique for massive mimo systems"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-4 (induced by source paper "interference coordination for aerial and terrestrial nodes in three tier lte advanced hetnet"):
  with members:
    - "exploiting lte advanced hetnets and feicic for uav assisted public safety communications"
    - "a survey on legacy and emerging technologies for public safety communications"
    - "coexistence of terrestrial and aerial users in cellular networks"
    - "designing and implementing future aerial communication networks"

Connected through hyperedge HE-5 (induced by source paper "optimization of massive full dimensional mimo for positioning and communication"):
  with members:
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "a pessimistic approximation for the fisher information measure"
    - "sectoring in multi cell massive mimo systems"
    - "layered downlink precoding for c ran systems with full dimensional mimo"
    - "positioning for the internet of things a 3gpp perspective"
    - "downlink achievable rate analysis in massive mimo systems with one bit dacs"
    - "optimal fronthaul quantization for cloud radio positioning"
    - "parallel and distributed methods for nonconvex optimization part ii applications"

Connected through hyperedge HE-6 (induced by source paper "multi layer precoding a potential solution for full dimensional massive mimo systems"):
  with members:
    - "low complexity massive mimo subspace estimation and tracking from low dimensional projections"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "subspace estimation and decomposition for large millimeter wave mimo systems"
    - "massive mimo ten myths and one critical question"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "massive mimo with multi cell mmse processing exploiting all pilots for interference suppression"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-7 (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"
    - "a generalized spatial correlation model for 3d mimo channels based on the fourier coefficients of power spectrums"
    - "massive mimo for next generation wireless systems"
    - "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-8 (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"
    - "a generalized spatial correlation model for 3d mimo channels based on the fourier coefficients of power spectrums"
    - "scaling up mimo opportunities and challenges with very large arrays"

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)