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: "waveform optimization for swipt with nonlinear energy harvester modeling"
  Abstract: Simultaneous Wireless Information and Power Transfer (SWIPT) has attracted significant attention in the communication community. The problem of waveform design for SWIPT has however never been addressed so far. In this paper, a novel SWIPT transceiver architecture is introduced relying on the superposition of multisine and OFDM waveforms at the transmitter and a power-splitter receiver equipped with an energy harvester and an information decoder capable of cancelling the multisine waveforms. The SWIPT multisine/OFDM waveforms are optimized so as to maximize the rate-energy region of the whole system. They are adaptive to the channel state information and result from a posynomial maximization problem that originates from the non-linearity of the energy harvester. Numerical results illustrate the performance of the derived waveforms and SWIPT architecture.

Connected through hyperedge HE-1 (induced by source paper "multi tone signal optimization for wireless power transfer in the presence of wireless communication links"):
  with members:
    - "retrodirective multi user wireless power transfer with massive mimo"
    - "low complexity adaptive multisine waveform design for wireless power transfer"
    - "waveform optimization for radio frequency wireless power transfer"
    - "waveform design for wireless power transfer"
    - "wireless powered communication opportunities and challenges"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "multi antenna wireless energy transfer for backscatter communication systems"
    - "simultaneous wireless information and power transfer in a two user ofdm interference channel"

Connected through hyperedge HE-2 (induced by source paper "on capacity achieving distributions over complex awgn channels under nonlinear power constraints and their applications to swipt"):
  with members:
    - "gaussian multiple access channels with one bit quantizer at the receiver"
    - "modulation design for wireless information and power transfer with nonlinear energy harvester modeling"
    - "on the capacity of swipt systems with a nonlinear energy harvesting circuit"
    - "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 design for wireless power transfer"
    - "wireless information and power transfer nonlinearity waveform design and rate energy tradeoff"

Connected through hyperedge HE-3 (induced by source paper "towards the 1g of mobile power network rf signal and system designs to make smart objects autonomous"):
  with members:
    - "waveform design for wireless power transfer with limited feedback"
    - "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 design for wireless power transfer"
    - "wireless information and power transfer nonlinearity waveform design and rate energy tradeoff"
    - "waveform optimization for large scale multi antenna multi sine wireless power transfer"

Connected through hyperedge HE-4 (induced by source paper "wirelessly powered backscatter communications waveform design and snr energy tradeoff"):
  with members:
    - "waveform design for wireless power transfer"
    - "waveform optimization for large scale multi antenna multi sine wireless power transfer"
    - "wirelessly powered backscatter communication networks modeling coverage and capacity"
    - "communications and signals design for wireless power transmission"
    - "multi antenna wireless energy transfer for backscatter communication systems"
    - "waveform optimization for wireless power transfer with nonlinear energy harvester modeling"

Connected through hyperedge HE-5 (induced by source paper "wireless information and power transfer over an awgn channel nonlinearity and asymmetric gaussian signaling"):
  with members:
    - "waveform design for wireless power transfer"
    - "waveform and transceiver design for simultaneous wireless information and power transfer"
    - "relaying strategies for wireless powered mimo relay networks"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-6 (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-7 (induced by source paper "waveform and transceiver design for simultaneous wireless information and power transfer"):
  with members:
    - "waveform optimization for large scale multi antenna multi sine wireless power transfer"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"
    - "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-8 (induced by source paper "waveform design for wireless power transfer"):
  with members:
    - "waveform optimization for large scale multi antenna multi sine wireless power transfer"
    - "simultaneous wireless information and power transfer in a two user ofdm interference channel"
    - "waveform optimization for wireless power transfer with nonlinear energy harvester modeling"
    - "energy beamforming with one bit feedback"
    - "simultaneous information and power transfer for broadband wireless systems"
    - "wireless information and power transfer architecture design and rate energy tradeoff"

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)