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: "joint wireless information and power transfer for an autonomous multiple antenna relay system"
  Abstract: Considering a three-node multiple antenna relay system, this paper proposes a two-phase amplify-and-forward (AF) relaying protocol, which enables the autonomous relay to simultaneously harvest wireless power from the source information signal and from an energy signal conveyed by the destination. We first study this energy-flow-assisted (EFA) relaying in a single-input single-output (SISO) relay system and aim at maximizing the rate. By transforming the optimization problem into an equivalent convex form, a global optimum can be found. We then extend the protocol to a multiple antenna relay system. The relay processing matrix is optimized to maximize the rate. The optimization problem can be efficiently solved by eigenvalue decomposition, after linear algebra manipulation. It is observed that the benefits of the energy flow are interestingly shown only in the multiple antenna case, and it is revealed that the received information signal and the energy leakage at the relay can be nearly separated by making use of the signal space, such that the desired signal can be amplified with a larger coefficient.

Connected through hyperedge HE-1 (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"
    - "training based swipt optimal power splitting at the receiver"
    - "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-2 (induced by source paper "joint resource allocation in swipt based multi antenna decode and forward relay networks"):
  with members:
    - "power allocation for secure swipt systems with wireless powered cooperative jamming"
    - "relaying strategies for wireless powered mimo relay networks"
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "information and energy cooperation in ofdm relaying protocols and optimization"
    - "joint power splitting and antenna selection in energy harvesting relay channels"
    - "energy harvesting for physical layer security in ofdma networks"
    - "enhancing wireless information and power transfer by exploiting multi antenna techniques"
    - "wireless information and energy transfer for two hop non regenerative mimo ofdm relay networks"

Connected through hyperedge HE-3 (induced by source paper "wireless charging technologies fundamentals standards and network applications"):
  with members:
    - "secrecy wireless information and power transfer in fading wiretap channel"
    - "resource allocation in wireless networks with rf energy harvesting and transfer"
    - "wireless powered communication opportunities and challenges"
    - "performance analysis of ambient rf energy harvesting with repulsive point process modeling"
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "green wireless power transfer networks"
    - "energy harvesting wireless communications a review of recent advances"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"

Connected through hyperedge HE-4 (induced by source paper "wireless information and power transfer nonlinearity waveform design and rate energy tradeoff"):
  with members:
    - "waveform design for wireless power transfer with limited feedback"
    - "wirelessly powered backscatter communications waveform design and snr energy tradeoff"
    - "large scale multiantenna multisine wireless power transfer"
    - "wireless information and power transfer over an awgn channel nonlinearity and asymmetric gaussian signaling"
    - "prototyping and experimentation of a closed loop wireless power transmission with channel acquisition and waveform optimization"
    - "low complexity adaptive multisine waveform design for wireless power transfer"
    - "waveform optimization for radio frequency wireless power transfer"
    - "waveform design for wireless power transfer"

Connected through hyperedge HE-5 (induced by source paper "relaying strategies for wireless powered mimo relay networks"):
  with members:
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "joint power splitting and antenna selection in energy harvesting relay channels"
    - "joint wireless information and power transfer in a three node autonomous mimo relay network"
    - "joint resource optimization for multicell networks with wireless energy harvesting relays"
    - "user cooperation in wireless powered communication networks"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "cooperative algorithms for mimo amplify and forward relay networks"

Connected through hyperedge HE-6 (induced by source paper "waveform and transceiver design for simultaneous wireless information and power transfer"):
  with members:
    - "waveform optimization for swipt with nonlinear energy harvester modeling"
    - "waveform optimization for large scale multi antenna multi sine wireless power transfer"
    - "waveform optimization for wireless power transfer with nonlinear energy harvester modeling"
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "simultaneous information and power transfer for broadband wireless systems"
    - "wireless information and power transfer in multiuser ofdm systems"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "wireless information and power transfer architecture design and rate energy tradeoff"

Connected through hyperedge HE-7 (induced by source paper "destination aided wireless power transfer in energy limited cognitive relay systems"):
  with members:
    - "transceiver design to maximize the weighted sum secrecy rate in full duplex swipt systems"
    - "multi objective optimization for robust power efficient and secure full duplex wireless communication systems"
    - "joint power splitting and secure beamforming design in the wireless powered untrusted relay networks"
    - "joint beamforming optimization and power control for full duplex mimo two way relay channel"
    - "information and energy cooperation in cognitive radio networks"
    - "secrecy wireless information and power transfer with miso beamforming"
    - "throughput maximization in wireless powered communication networks"
    - "cooperative cognitive networks optimal distributed and low complexity algorithms"

Connected through hyperedge HE-8 (induced by source paper "waveform optimization for swipt with nonlinear energy harvester modeling"):
  with members:
    - "waveform optimization for wireless power transfer with nonlinear energy harvester modeling"
    - "simultaneous information and power transfer for broadband wireless systems"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "wireless information and power transfer architecture design and rate energy tradeoff"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

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)