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: "cognitive mimo radio"
  Abstract: Radio regulatory bodies are recognizing that the rigid spectrum assignment granting exclusive use to licensed services is highly inefficient, due to the high variability of the traffic statistics across time, space, and frequency. Recent Federal Communications Commission (FCC) measurements show that, in fact, the spectrum usage is typically concentrated over certain portions of the spectrum, while a significant amount of the licensed bands (or idle slots in static time division multiple access (TDMA) systems with bursty traffic) remains unused or underutilized for 90% of time [1]. It is not surprising then that this inefficiency is motivating a flurry of research activities in the engineering, economics, and regulation communities in the effort of finding more efficient spectrum management policies.

Connected through hyperedge HE-1 (induced by source paper "sense and predict harnessing spatial interference correlation for cognitive radio networks"):
  with members:
    - "ultra reliable and low latency communications in 5g downlink physical layer aspects"
    - "millimeter wave interference avoidance via building aware associations"
    - "the connectivity of millimeter wave networks in urban environments modeled using random lattices"
    - "macro diversity in cellular networks with random blockages"
    - "sense and predict opportunistic mac based on spatial interference correlation for cognitive radio networks"
    - "downlink and uplink cell association with traditional macrocells and millimeter wave small cells"
    - "spatio temporal interference correlation and joint coverage in cellular networks"
    - "design and analysis of initial access in millimeter wave cellular networks"

Connected through hyperedge HE-2 (induced by source paper "energy efficiency in mimo underlay and overlay device to device communications and cognitive radio systems"):
  with members:
    - "energy efficient power control a look at 5g wireless technologies"
    - "energy efficiency and sum rate when massive mimo meets device to device communication"
    - "energy efficient resource allocation for device to device underlay communication"
    - "dynamic power control for delay aware device to device communications"
    - "resource allocation under channel uncertainties for relay aided device to device communication underlaying lte a cellular networks"
    - "energy efficiency and spectral efficiency tradeoff in device to device d2d communications"
    - "designing multi user mimo for energy efficiency when is massive mimo the answer"
    - "cognitive beamforming for multiple secondary data streams with individual snr constraints"

Connected through hyperedge HE-3 (induced by source paper "distributed energy efficient cross layer optimization for multihop mimo cognitive radio networks with primary user rate protection"):
  with members:
    - "database assisted distributed spectrum sharing"
    - "outage constrained robust transmit optimization for multiuser miso downlinks tractable approximations by conic optimization"
    - "dynamic resource allocation in cognitive radio networks"
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"

Connected through hyperedge HE-4 (induced by source paper "massive mimo unlicensed a new approach to dynamic spectrum access"):
  with members:
    - "massive mimo unlicensed for high performance indoor networks"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"

Connected through hyperedge HE-5 (induced by source paper "opportunistic spectrum sharing in dynamic access networks deployment challenges optimizations solutions and open issues"):
  with members:
    - "exploiting self interference suppression for improved spectrum awareness efficiency in cognitive radio systems"
    - "channel assignment with access contention resolution for cognitive radio networks"
    - "optimal multiband joint detection for spectrum sensing in cognitive radio networks"

Connected through hyperedge HE-6 (induced by source paper "fifty years of mimo detection the road to large scale mimos"):
  with members:
    - "large scale mimo detection for 3gpp lte algorithms and fpga implementations"
    - "an esprit based approach for 2 d localization of incoherently distributed sources in massive mimo systems"
    - "massive mimo for next generation wireless systems"
    - "what will 5g be"
    - "approximate bayesian probabilistic data association aided iterative detection for mimo systems using arbitrary m ary modulation"
    - "channel hardening exploiting message passing chemp receiver in large scale mimo systems"
    - "five disruptive technology directions for 5g"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-7 (induced by source paper "real and complex monotone communication games"):
  with members:
    - "game theoretic methods for the smart grid"
    - "dynamic resource allocation in cognitive radio networks"
    - "the mimo iterative waterfilling algorithm"
    - "optimal linear precoding strategies for wideband noncooperative systems based on game theory part i nash equilibria"
    - "competitive design of multiuser mimo systems based on game theory a unified view"
    - "femtocell networks a survey"
    - "distributed power allocation with rate constraints in gaussian parallel interference channels"
    - "uplink capacity and interference avoidance for two tier femtocell networks"

Connected through hyperedge HE-8 (induced by source paper "transmit antenna selection in underlay cognitive radio environment"):
  with members:
    - "difference antenna selection and power allocation for wireless cognitive systems"
    - "optimal power allocation for fading channels in cognitive radio networks ergodic capacity and outage capacity"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"

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)