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: "noma in 5g systems exciting possibilities for enhancing spectral efficiency"
  Abstract: This article provides an overview of power-domain non-orthogonal multiple access for 5G systems. The basic concepts and benefits are briefly presented, along with current solutions and standardization activities. In addition, limitations and research challenges are discussed.

Connected through hyperedge HE-1 (induced by source paper "non orthogonal multiple access noma how it meets 5g and beyond"):
  with members:
    - "securing downlink massive mimo noma networks with artificial noise"
    - "energy efficient joint user rb association and power allocation for uplink hybrid noma oma"
    - "capacity and outage analysis of a dual hop decode and forward relay aided noma scheme"
    - "energy efficient power allocation in uplink mmwave massive mimo with noma"
    - "optimal joint subcarrier and power allocation in noma is strongly np hard"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "a two phase power allocation scheme for crns employing noma"

Connected through hyperedge HE-2 (induced by source paper "securing downlink massive mimo noma networks with artificial noise"):
  with members:
    - "energy efficient joint user rb association and power allocation for uplink hybrid noma oma"
    - "energy efficient power allocation in uplink mmwave massive mimo with noma"
    - "exploiting inter user interference for secure massive non orthogonal multiple access"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "resource allocation for downlink noma systems key techniques and open issues"
    - "a fair individual rate comparison between mimo noma and mimo oma"

Connected through hyperedge HE-3 (induced by source paper "energy efficient joint user rb association and power allocation for uplink hybrid noma oma"):
  with members:
    - "energy efficient power allocation in uplink mmwave massive mimo with noma"
    - "energy efficient noma enabled heterogeneous cloud radio access networks"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "resource allocation for downlink noma systems key techniques and open issues"
    - "joint power control and beamforming for uplink non orthogonal multiple access in 5g millimeter wave communications"
    - "a fair individual rate comparison between mimo noma and mimo oma"
    - "capacity comparison between mimo noma and mimo oma with multiple users in a cluster"

Connected through hyperedge HE-4 (induced by source paper "energy efficient power allocation in uplink mmwave massive mimo with noma"):
  with members:
    - "spectrum and energy efficient beamspace mimo noma for millimeter wave communications using lens antenna array"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "resource allocation for downlink noma systems key techniques and open issues"
    - "joint power control and beamforming for uplink non orthogonal multiple access in 5g millimeter wave communications"
    - "capacity comparison between mimo noma and mimo oma with multiple users in a cluster"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "spatially sparse precoding in millimeter wave mimo systems"

Connected through hyperedge HE-5 (induced by source paper "on the performance of network noma in uplink comp systems a stochastic geometry approach"):
  with members:
    - "impact of non orthogonal multiple access on the offloading of mobile edge computing"
    - "poisson cox point processes for vehicular networks"
    - "an analytical framework for coverage in cellular networks leveraging vehicles"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "resource allocation for downlink noma systems key techniques and open issues"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "optimal power allocation scheme for non orthogonal multiple access with alpha fairness"
    - "coverage analysis of a vehicular network modeled as cox process driven by poisson line process"

Connected through hyperedge HE-6 (induced by source paper "joint beamforming and power allocation in downlink noma multiuser mimo networks"):
  with members:
    - "joint beamforming and power splitting control in downlink cooperative swipt noma systems"
    - "capacity comparison between mimo noma and mimo oma with multiple users in a cluster"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "design of massive mimo noma with limited feedback"
    - "on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming"
    - "a minorization maximization method for optimizing sum rate in the downlink of non orthogonal multiple access systems"
    - "non orthogonal multiple access noma for downlink multiuser mimo systems user clustering beamforming and power allocation"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"

Connected through hyperedge HE-7 (induced by source paper "resource allocation for downlink noma systems key techniques and open issues"):
  with members:
    - "spectrum and energy efficient beamspace mimo noma for millimeter wave communications using lens antenna array"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "a fair individual rate comparison between mimo noma and mimo oma"
    - "capacity comparison between mimo noma and mimo oma with multiple users in a cluster"
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "resource management in non orthogonal multiple access networks for 5g and beyond"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"
    - "fairness for non orthogonal multiple access in 5g systems"

Connected through hyperedge HE-8 (induced by source paper "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"):
  with members:
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "capacity comparison between mimo noma and mimo oma with multiple users in a cluster"
    - "design of massive mimo noma with limited feedback"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "energy efficient transmission design in non orthogonal multiple access"
    - "non orthogonal multiple access noma for downlink multiuser mimo systems user clustering beamforming and power allocation"
    - "spatially sparse precoding in millimeter wave mimo 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)