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: "unified performance analysis of mixed radio frequency free space optical dual hop transmission systems"
  Abstract: The mixed radio frequency (RF)/free-space optical (FSO) relaying is a promising technology for coverage improvement, while there lacks unified expressions to describe its performance. In this paper, a unified performance analysis framework of a dual-hop relay system over asymmetric RF/FSO links is presented. More specifically, we consider the RF link follows generalized   $\kappa$  -   $\mu$   or    $\eta$  -  $\mu$    distributions, while the FSO link experiences the gamma-gamma distribution, respectively. Novel analytical expressions of the probability density function and cumulative distribution function are derived. We then capitalize on these results to provide new exact analytical expressions of the outage probability and bit error rate (BER). Furthermore, the outage probability for high signal-to-noise ratios and the BER for different modulation schemes are deduced to provide useful insights into the impact of system and channel parameters of the overall system performance. These accurate expressions are general, since they correspond to generalized fading in the RF link and account for pointing errors, atmospheric turbulence, and different modulation schemes in the FSO link. The links between derived results and previous results are presented. Finally, numerical and Monte–Carlo simulation results are provided to demonstrate the validity of the proposed unified expressions.

Connected through hyperedge HE-1 (induced by source paper "shadowed fso mmwave systems with interference"):
  with members:
    - "performance of a free space optical relay assisted hybrid rf fso system in generalized m distributed channels"
    - "mimo channel modeling and capacity analysis for 5g millimeter wave wireless systems"
    - "5g ultra dense cellular networks"
    - "on the ergodic capacity of underlay cognitive dual hop af relayed systems under non identical generalized k fading channels"
    - "coverage and rate analysis for millimeter wave cellular networks"
    - "millimeter wave channel modeling and cellular capacity evaluation"
    - "on the capacity of free space optical intensity channels"

Connected through hyperedge HE-2 (induced by source paper "performance analysis of a hybrid downlink uplink cooperative noma scheme"):
  with members:
    - "power efficient resource allocation for mc noma with statistical channel state information"
    - "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "resource management in non orthogonal multiple access networks for 5g and beyond"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "multi antenna relay aided wireless physical layer security"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"

Connected through hyperedge HE-3 (induced by source paper "on the performance of millimeter wave based rf fso multi hop and mesh networks"):
  with members:
    - "performance analysis of free space optical links over m a laga mathcal m turbulence channels with pointing errors"
    - "on the performance of rf fso links with and without hybrid arq"
    - "unified performance analysis of mixed line of sight rf fso fixed gain dual hop transmission systems"
    - "impact of pointing errors on the performance of mixed rf fso dual hop transmission systems"
    - "on the benefits of partial channel state information for repetition protocols in block fading channels"
    - "on the capacity of free space optical intensity channels"

Connected through hyperedge HE-4 (induced by source paper "performance analysis of rf fso multi hop networks"):
  with members:
    - "on the performance of millimeter wave based rf fso multi hop and mesh networks"
    - "on the performance of rf fso links with and without hybrid arq"
    - "impact of pointing errors on the performance of mixed rf fso dual hop transmission systems"

Connected through hyperedge HE-5 (induced by source paper "achievable rate analysis of relay assisted cooperative noma over rician fading channels"):
  with members:
    - "on the performance of noma based cooperative relaying systems over rician fading channels"
    - "lattice partition multiple access a new method of downlink non orthogonal multiuser transmissions"
    - "scma codebook design"

Connected through hyperedge HE-6 (induced by source paper "on the multivariate gamma gamma distribution with arbitrary correlation and applications in wireless communications"):
  with members:
    - "on the ergodic capacity of mimo free space optical systems over turbulence channels"
    - "statistical characterization of kappa mu shadowed fading"
    - "on the distribution of the sum of gamma gamma variates and applications in rf and optical wireless communications"

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)