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: "optimal user scheduling and power allocation for millimeter wave noma systems"
  Abstract: This paper investigates the application of non-orthogonal multiple access (NOMA) in millimeter wave (mmWave) communications by exploiting beamforming, user scheduling and power allocation. Random beamforming is invoked for reducing the feedback overhead of considered systems. A nonconvex optimization problem for maximizing the sum rate is formulated, which is proved to be NP-hard. The branch and bound (BB) approach is invoked to obtain the optimal power allocation policy, which is proved to converge to a global optimal solution. To elaborate further, low complexity suboptimal approach is developed for striking a good computational complexity-optimality tradeoff, where matching theory and successive convex approximation (SCA) techniques are invoked for tackling the user scheduling and power allocation problems, respectively. Simulation results reveal that: i) the proposed low complexity solution achieves a near-optimal performance; and ii) the proposed mmWave NOMA systems is capable of outperforming conventional mmWave orthogonal multiple access (OMA) systems in terms of sum rate and the number of served users.

Connected through hyperedge HE-1 (induced by source paper "resource allocation in intelligent reflecting surface assisted noma systems"):
  with members:
    - "joint active and passive beamforming optimization for intelligent reflecting surface assisted swipt under qos constraints"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "power efficient irs assisted noma"
    - "intelligent reflecting surface meets ofdm protocol design and rate maximization"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "intelligent reflecting surface design for mimo system by maximizing sum path gains"
    - "a simple design of irs noma transmission"
    - "towards smart radio environment for wireless communications via intelligent reflecting surfaces a comprehensive survey"

Connected through hyperedge HE-2 (induced by source paper "a survey of rate optimal power domain noma schemes for enabling technologies of future wireless networks"):
  with members:
    - "generalized coordinated multipoint gcomp enabled noma outage capacity and power allocation"
    - "what role can noma play in massive mimo"
    - "uav data collection over noma backscatter networks uav altitude and trajectory optimization"
    - "uav communications for 5g and beyond recent advances and future trends"
    - "when full duplex wireless meets non orthogonal multiple access opportunities and challenges"
    - "on optimizing vlc networks for downlink multi user transmission a survey"
    - "beam design and user scheduling for nonorthogonal multiple access with multiple antennas based on pareto optimality"
    - "spatial modulation assisted multi antenna non orthogonal multiple access"

Connected through hyperedge HE-3 (induced by source paper "clustered millimeter wave networks with non orthogonal multiple access"):
  with members:
    - "cache enabled hetnets with millimeter wave small cells"
    - "user association and resource allocation in unified noma enabled heterogeneous ultra dense networks"
    - "exploiting multiple access in clustered millimeter wave networks noma or oma"
    - "modeling and analysis of d2d millimeter wave networks with poisson cluster processes"
    - "modeling and analyzing millimeter wave cellular systems"
    - "coverage analysis for millimeter wave networks the impact of directional antenna arrays"
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"

Connected through hyperedge HE-4 (induced by source paper "beamwidth control for noma in hybrid mmwave communication systems"):
  with members:
    - "multi beam noma for hybrid mmwave systems"
    - "on low resolution adcs in practical 5g millimeter wave massive mimo systems"
    - "a multi beam noma framework for hybrid mmwave systems"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "spectrum and energy efficient beamspace mimo noma for millimeter wave communications using lens antenna array"
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "noma meets finite resolution analog beamforming in massive mimo and millimeter wave networks"

Connected through hyperedge HE-5 (induced by source paper "lens based millimeter wave reconfigurable antenna noma"):
  with members:
    - "a new reconfigurable antenna mimo architecture for mmwave communication"
    - "a machine learning approach for power allocation in hetnets considering qos"
    - "reconfigurable antenna multiple access for 5g mmwave systems"
    - "impact of beam misalignment on hybrid beamforming noma for mmwave communications"
    - "noma principles and recent results"
    - "fronthauling for 5g lte u ultra dense cloud small cell networks"
    - "5g ultra dense cellular networks"
    - "spatially sparse precoding in millimeter wave mimo systems"

Connected through hyperedge HE-6 (induced by source paper "design of non orthogonal beamspace multiple access for cellular internet of things"):
  with members:
    - "beam design and user scheduling for nonorthogonal multiple access with multiple antennas based on pareto optimality"
    - "non orthogonal multiple access common myths and critical questions"
    - "performance analysis of noma in training based multiuser mimo systems"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "design of massive mimo noma with limited feedback"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "why does the kronecker model result in misleading capacity estimates"

Connected through hyperedge HE-7 (induced by source paper "uplink non orthogonal multiple access over mixed rf fso systems"):
  with members:
    - "multi beam noma for hybrid mmwave systems"
    - "exploiting full half duplex user relaying in noma systems"
    - "a low complexity recursive approach toward code domain noma for massive communications"
    - "performance analysis of noma for ultra reliable and low latency communications"
    - "modeling and analyzing millimeter wave cellular systems"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "5g wireless backhaul networks challenges and research advances"

Connected through hyperedge HE-8 (induced by source paper "blind signal classification analysis and impact on user scheduling and power allocation in nonorthogonal multiple access"):
  with members:
    - "bi directional cooperative noma without full csit"
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "quadrature amplitude modulation division for multiuser miso broadcast channels"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "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)