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: "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"
  Abstract: Non-orthogonal multiple access (NOMA) has been recognized as a promising multiple access technique for the next generation cellular communication networks. In this paper, we first discuss a simple NOMA model with two users served by a single-carrier simultaneously to illustrate its basic principles. Then, a more general model with multicarrier serving an arbitrary number of users on each subcarrier is also discussed. An overview of existing works on performance analysis, resource allocation, and multiple-input multiple-output NOMA are summarized and discussed. Furthermore, we discuss the key features of NOMA and its potential research challenges.

Connected through hyperedge HE-1 (induced by source paper "random access for massive machine type communications"):
  with members:
    - "beamwidth control for noma in hybrid mmwave communication systems"
    - "design of non orthogonal beamspace multiple access for cellular internet of things"
    - "on the performance gain of noma over oma in uplink single cell systems"
    - "multi beam noma for hybrid mmwave systems"
    - "joint pilot and payload power control for uplink mimo noma with mrc sic receivers"
    - "reliability based windowed decoding for spatially coupled ldpc codes"
    - "short packet downlink transmission with non orthogonal multiple access"
    - "a multi beam noma framework for hybrid mmwave systems"

Connected through hyperedge HE-2 (induced by source paper "lattice coding for downlink multiuser transmission"):
  with members:
    - "downlink non orthogonal multiple access without sic for block fading channels an algebraic rotation approach"
    - "joint pilot and payload power control for uplink mimo noma with mrc sic receivers"
    - "short packet downlink transmission with non orthogonal multiple access"
    - "a multi beam noma framework for hybrid mmwave systems"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "improved decoding and error floor analysis of staircase codes"
    - "performance analysis of a hybrid downlink uplink cooperative noma scheme"
    - "on non orthogonal multiple access with finite alphabet inputs in z channels"

Connected through hyperedge HE-3 (induced by source paper "on the performance gain of noma over oma in uplink communication systems"):
  with members:
    - "a two stage beam alignment framework for hybrid mmwave distributed antenna systems"
    - "on the performance gain of noma over oma in uplink single cell systems"
    - "a distributed multi rf chain hybrid mmwave scheme for small cell systems"
    - "multi beam noma for hybrid mmwave systems"
    - "joint pilot and payload power control for uplink mimo noma with mrc sic receivers"
    - "multi cell hybrid millimeter wave systems pilot contamination and interference mitigation"
    - "noma aided narrowband iot for machine type communications with user clustering"
    - "non orthogonal multiple access common myths and critical questions"

Connected through hyperedge HE-4 (induced by source paper "power allocation in cache aided noma systems optimization and deep reinforcement learning approaches"):
  with members:
    - "resource allocation in noma based fog radio access networks"
    - "non orthogonal multiple access common myths and critical questions"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "noma assisted wireless caching strategies and performance analysis"
    - "non orthogonal multiple access in multi cell networks theory performance and practical challenges"
    - "adam a method for stochastic optimization"
    - "fundamental limits of caching in wireless d2d networks"

Connected through hyperedge HE-5 (induced by source paper "on the performance gain of noma over oma in uplink single cell systems"):
  with members:
    - "joint pilot and payload power control for uplink mimo noma with mrc sic receivers"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "performance analysis of a hybrid downlink uplink cooperative noma scheme"
    - "an optimization perspective of the superiority of noma compared to conventional oma"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"

Connected through hyperedge HE-6 (induced by source paper "multi beam noma for hybrid mmwave systems"):
  with members:
    - "on low resolution adcs in practical 5g millimeter wave massive mimo systems"
    - "a multi beam noma framework for hybrid mmwave systems"
    - "rate splitting multiple access for downlink communication systems bridging generalizing and outperforming sdma and noma"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "optimal user scheduling and power allocation for millimeter wave noma systems"
    - "millimeter wave communication with non orthogonal multiple access for 5g"
    - "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"

Connected through hyperedge HE-7 (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-8 (induced by source paper "a multi beam noma framework for hybrid mmwave systems"):
  with members:
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "optimal user scheduling and power allocation for millimeter wave noma systems"
    - "millimeter wave communication with non orthogonal multiple access for 5g"
    - "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"
    - "power efficient resource allocation for mc noma with statistical channel state information"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "a minorization maximization method for optimizing sum rate in the downlink of non orthogonal multiple access 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)