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: "spectral efficiency of mimo millimeter wave links with single carrier modulation for 5g networks"
  Abstract: Future wireless networks will extensively rely upon bandwidths centered on carrier frequencies larger than 10GHz. Indeed, recent research has shown that, despite the large path-loss, millimeter wave (mmWave) frequencies can be successfully exploited to transmit very large data-rates over short distances to slowly moving users. Due to hardware complexity and cost constraints, single-carrier modulation schemes, as opposed to the popular multi-carrier schemes, are being considered for use at mmWave frequencies. This paper presents preliminary studies on the achievable spectral efficiency on a wireless MIMO link operating at mmWave in a typical 5G scenario. Two different single-carrier modem schemes are considered, i.e. a traditional modulation scheme with linear equalization at the receiver, and a single-carrier modulation with cyclic prefix, frequency-domain equalization and FFT-based processing at the receiver. Our results show that the former achieves a larger spectral efficiency than the latter. Results also confirm that the spectral efficiency increases with the dimension of the antenna array, as well as that performance gets severely degraded when the link length exceeds 100 meters and the transmit power falls below 0dBW. Nonetheless, mmWave appear to be very suited for providing very large data-rates over short distances.

Connected through hyperedge HE-1 (induced by source paper "massive mimo 5g cellular networks mm wave versus mu wave frequencies"):
  with members:
    - "doubly massive mmwave mimo systems using very large antenna arrays at both transmitter and receiver"
    - "are mmwave low complexity beamforming structures energy efficient analysis of the downlink mu mimo"
    - "subspace estimation and decomposition for large millimeter wave mimo systems"
    - "cell free massive mimo versus small cells"
    - "on clustered statistical mimo millimeter wave channel simulation"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-2 (induced by source paper "doubly massive mmwave mimo systems using very large antenna arrays at both transmitter and receiver"):
  with members:
    - "enhancing the estimation of mm wave large array channels by exploiting spatio temporal correlation and sparse scattering"
    - "on clustered statistical mimo millimeter wave channel simulation"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"
    - "subspace estimation and decomposition for hybrid analog digital millimetre wave mimo systems"
    - "massive antenna arrays with low front end hardware complexity an enabling technology for the emerging small cell and distributed network architectures"
    - "massive mimo for next generation wireless systems"
    - "what will 5g be"

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)