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: "cooperative energy harvesting networks with spatially random users"
  Abstract: This letter considers a cooperative network with multiple source-destination pairs and one energy harvesting relay. The outage probability experienced by users in this network is characterized by taking the spatial randomness of user locations into consideration. In addition, the cooperation among users is modeled as a canonical coalitional game and the grand coalition is shown to be stable in the addressed scenario. Simulation results are provided to demonstrate the accuracy of the developed analytical results.

Connected through hyperedge HE-1 (induced by source paper "a unified framework for non orthogonal multiple access"):
  with members:
    - "exploiting full half duplex user relaying in noma systems"
    - "user association and resource allocation in unified noma enabled heterogeneous ultra dense networks"
    - "performance analysis of noma with fixed gain relaying over nakagami m fading channels"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "modulation and multiple access for 5g networks"
    - "fundamentals of modeling finite wireless networks using binomial point process"
    - "on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming"
    - "enhancing the physical layer security of non orthogonal multiple access in large scale networks"

Connected through hyperedge HE-2 (induced by source paper "wireless networks with energy harvesting and power transfer joint power and time allocation"):
  with members:
    - "harvest then cooperate wireless powered cooperative communications"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "performance analysis of wireless powered communication with finite infinite energy storage"
    - "throughput maximization in wireless powered communication networks"
    - "throughput maximization for an energy harvesting communication system with processing cost"
    - "optimal energy allocation for wireless communications with energy harvesting constraints"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-3 (induced by source paper "swipt in 3 d bipolar ad hoc networks with sectorized antennas"):
  with members:
    - "layered downlink precoding for c ran systems with full dimensional mimo"
    - "millimeter wave energy harvesting"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "mimo broadcasting for simultaneous wireless information and power transfer"
    - "transmission capacity of ad hoc networks with spatial diversity"

Connected through hyperedge HE-4 (induced by source paper "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"):
  with members:
    - "wireless energy harvesting in a cognitive relay network"
    - "nonorthogonal multiple access in large scale underlay cognitive radio networks"
    - "uplink non orthogonal multiple access for 5g wireless networks"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-5 (induced by source paper "wireless powered communications performance analysis and optimization"):
  with members:
    - "wireless information and power transfer in relay systems with multiple antennas and interference"
    - "harvest then cooperate wireless powered cooperative communications"
    - "optimized training for net energy maximization in multi antenna wireless energy transfer over frequency selective channel"
    - "cutting last wires for mobile communication by microwave power transfer"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "optimized training design for wireless energy transfer"
    - "simultaneous information and energy transfer in large scale networks with without relaying"
    - "dynamic resource allocation for multiple antenna wireless power transfer"

Connected through hyperedge HE-6 (induced by source paper "wireless information and power transfer in relay systems with multiple antennas and interference"):
  with members:
    - "information and energy cooperation in cognitive radio networks"
    - "outage probability of dual hop multiple antenna af systems with linear processing in the presence of co channel interference"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "ergodic capacity comparison of different relay precoding schemes in dual hop af systems with co channel interference"
    - "secrecy wireless information and power transfer with miso beamforming"
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "simultaneous information and energy transfer in large scale networks with without relaying"
    - "wireless information and energy transfer in multi antenna interference channel"

Connected through hyperedge HE-7 (induced by source paper "noncoherent relaying in energy harvesting communication systems"):
  with members:
    - "resource allocation in wireless networks with rf energy harvesting and transfer"
    - "wireless powered communication opportunities and challenges"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "energy harvesting noncoherent cooperative communications"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "simultaneous information and energy transfer in large scale networks with without relaying"
    - "simultaneous information and power transfer for broadband wireless systems"

Connected through hyperedge HE-8 (induced by source paper "harvest then cooperate wireless powered cooperative communications"):
  with members:
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "full duplex wireless powered communication network with energy causality"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "simultaneous information and energy transfer in large scale networks with without relaying"
    - "time switching uplink network coded cooperative communication with downlink energy transfer"
    - "throughput maximization in wireless powered communication 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)