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: "training based swipt optimal power splitting at the receiver"
  Abstract: We consider a point-to-point system with simultaneous wireless information and power transfer (SWIPT) over a block-fading channel. Each transmission block consists of a training phase and a data transmission phase. Pilot symbols are transmitted during the training phase for channel estimation at the receiver. To enable SWIPT, the receiver adopts a power-splitting design, such that a portion of the received signal is used for channel estimation or data detection, while the rest is used for energy harvesting. We optimally design the power-splitting ratios for both training and data phases to achieve the best ergodic capacity performance while maintaining a required energy harvesting rate. Our result shows how a power-splitting receiver can make the best use of the received pilot and data signals to obtain optimal SWIPT performance.

Connected through hyperedge HE-1 (induced by source paper "throughput maximization in two hop df multiple relay network with simultaneous wireless information and power transfer"):
  with members:
    - "sensitive and nonlinear far field rf energy harvesting in wireless communications"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "information and energy cooperation in ofdm relaying protocols and optimization"
    - "joint power splitting and antenna selection in energy harvesting relay channels"
    - "wireless information and energy transfer for two hop non regenerative mimo ofdm relay networks"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "wireless information and power transfer with full duplex relaying"

Connected through hyperedge HE-2 (induced by source paper "energy efficient swipt in iot distributed antenna systems"):
  with members:
    - "simultaneous wireless information and power transfer in cooperative relay networks with rateless codes"
    - "artificial noise aided secrecy information and power transfer in ofdma systems"
    - "energy efficient resource assignment and power allocation in heterogeneous cloud radio access networks"
    - "information and energy cooperation in ofdm relaying protocols and optimization"
    - "energy harvesting for physical layer security in ofdma networks"
    - "wireless information and energy transfer for two hop non regenerative mimo ofdm relay networks"
    - "secure and green swipt in distributed antenna networks with limited backhaul capacity"
    - "energy beamforming with one bit feedback"

Connected through hyperedge HE-3 (induced by source paper "wireless powered dual hop multi antenna relaying systems impact of csi and antenna correlation"):
  with members:
    - "on the performance of multi antenna wireless powered communications with energy beamforming"
    - "an overview of sustainable green 5g networks"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"
    - "wireless powered communications performance analysis and optimization"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "wireless information and power transfer in relay systems with multiple antennas and interference"
    - "harvest then cooperate wireless powered cooperative communications"
    - "wireless networks with rf energy harvesting a contemporary survey"

Connected through hyperedge HE-4 (induced by source paper "joint moo of transmit precoding and receiver design in a downlink time switching miso swipt system"):
  with members:
    - "multi objective beamforming for energy efficient swipt systems"
    - "wireless powered communication opportunities and challenges"
    - "resource allocation for coordinated multipoint networks with wireless information and power transfer"
    - "joint transmit beamforming and receive power splitting for miso swipt systems"
    - "wireless information and power transfer a dynamic power splitting approach"
    - "wireless information transfer with opportunistic energy harvesting"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-5 (induced by source paper "optimized training design for wireless energy transfer"):
  with members:
    - "wireless powered communication opportunities and challenges"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "energy beamforming with one bit feedback"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "dynamic spectrum access in cognitive radio networks with rf energy harvesting"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "dynamic resource allocation for multiple antenna wireless power 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)