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: "fast channel estimation for millimetre wave wireless systems using overlapped beam patterns"
  Abstract: This paper is concerned with the channel estimation problem in millimetre wave (MMW) wireless systems with large antenna arrays. By exploiting the sparse nature of the MMW channel, we present an efficient estimation algorithm based on a novel overlapped beam pattern design. The performance of the algorithm is analyzed and an upper bound on the probability of channel estimation failure is derived. Results show that the algorithm can significantly reduce the number of required measurements in channel estimation (e.g., by 225% when a single overlap is used) when compared to the existing channel estimation algorithm based on non-overlapped beam patterns.

Connected through hyperedge HE-1 (induced by source paper "compressed sensing channel estimation for ofdm with non gaussian multipath gains"):
  with members:
    - "average performance of orthogonal matching pursuit omp for sparse approximation"
    - "compressive channel estimation and tracking for large arrays in mm wave picocells"
    - "channel estimation for millimeter wave massive mimo with hybrid precoding over frequency selective fading channels"
    - "channel estimation for hybrid architecture based wideband millimeter wave systems"
    - "compressed sensing algorithms for ofdm channel estimation"
    - "channel estimation in broadband millimeter wave mimo systems with few bit adcs"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "distributed compressive csit estimation and feedback for fdd multi user massive mimo systems"

Connected through hyperedge HE-2 (induced by source paper "optimal precoders for tracking the aod and aoa of a mmwave path"):
  with members:
    - "robust location aided beam alignment in millimeter wave massive mimo"
    - "modeling and analyzing millimeter wave cellular systems"
    - "error bounds for uplink and downlink 3d localization in 5g mmwave systems"
    - "transmitter beam selection in millimeter wave mimo with in band position aiding"
    - "hierarchical codebook design for beamforming training in millimeter wave communication"
    - "millimeter wave vehicular communication to support massive automotive sensing"
    - "channel estimation for hybrid architecture based wideband millimeter wave systems"
    - "hybrid rf and digital beamformer for cellular networks algorithms microwave architectures and measurements"

Connected through hyperedge HE-3 (induced by source paper "ray of arrival passing for indirect beam training in cooperative millimeter wave mimo networks"):
  with members:
    - "improved handover through dual connectivity in 5g mmwave mobile networks"
    - "millimeter wave mimo channel estimation using overlapped beam patterns and rate adaptation"
    - "race a rate adaptive channel estimation approach for millimeter wave mimo systems"
    - "hierarchical codebook design for beamforming training in millimeter wave communication"
    - "initial access in 5g mmwave cellular networks"
    - "multi connectivity in 5g mmwave cellular networks"
    - "compressed sensing based multi user millimeter wave systems how many measurements are needed"
    - "5g ultra dense cellular networks"

Connected through hyperedge HE-4 (induced by source paper "beam on graph simultaneous channel estimation for mmwave mimo systems with multiple users"):
  with members:
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "millimeter wave mimo channel estimation using overlapped beam patterns and rate adaptation"
    - "race a rate adaptive channel estimation approach for millimeter wave mimo systems"
    - "fountain code inspired channel estimation for multi user millimeter wave mimo systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "sparse signal recovery using generalized approximate message passing with built in parameter estimation"
    - "massive mimo ten myths and one critical question"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"

Connected through hyperedge HE-5 (induced by source paper "beam on graph simultaneous channel estimation in multi user millimeter wave mimo systems"):
  with members:
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "millimeter wave mimo channel estimation using overlapped beam patterns and rate adaptation"
    - "race a rate adaptive channel estimation approach for millimeter wave mimo systems"
    - "fountain code inspired channel estimation for multi user millimeter wave mimo systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "sparse signal recovery using generalized approximate message passing with built in parameter estimation"
    - "massive mimo ten myths and one critical question"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"

Connected through hyperedge HE-6 (induced by source paper "millimeter wave mimo channel estimation using overlapped beam patterns and rate adaptation"):
  with members:
    - "race a rate adaptive channel estimation approach for millimeter wave mimo systems"
    - "hierarchical codebook design for beamforming training in millimeter wave communication"
    - "pilot beam sequence design for channel estimation in millimeter wave mimo systems a pomdp framework"
    - "iterative eigenvalue decomposition and multipath grouping tx rx joint beamformings for millimeter wave communications"
    - "iterative joint beamforming training with constant amplitude phased arrays in millimeter wave communications"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "millimeter wave cellular wireless networks potentials and challenges"
    - "millimeter wave channel modeling and cellular capacity evaluation"

Connected through hyperedge HE-7 (induced by source paper "channel estimation for hybrid architecture based wideband millimeter wave systems"):
  with members:
    - "channel estimation for millimeter wave massive mimo with hybrid precoding over frequency selective fading channels"
    - "structured compressive sensing based spatio temporal joint channel estimation for fdd massive mimo"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "auxiliary beam pair enabled aod and aoa estimation in closed loop large scale mmwave mimo systems"
    - "subspace estimation and decomposition for large millimeter wave mimo systems"
    - "frequency selective hybrid precoding for limited feedback millimeter wave systems"
    - "compressed sensing based multi user millimeter wave systems how many measurements are needed"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"

Connected through hyperedge HE-8 (induced by source paper "codebook design for millimeter wave channel estimation with hybrid precoding structure"):
  with members:
    - "hierarchical codebook design for beamforming training in millimeter wave communication"
    - "low complexity hybrid precoding and channel estimation based on hierarchical multi beam search for millimeter wave mimo systems"
    - "iterative eigenvalue decomposition and multipath grouping tx rx joint beamformings for millimeter wave communications"
    - "spatially common sparsity based adaptive channel estimation and feedback for fdd massive mimo"
    - "compressed sensing based multi user millimeter wave systems how many measurements are needed"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "massive mimo for next generation wireless systems"

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)