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 beamforming design and time allocation for wireless powered communication networks"
  Abstract: This paper investigates a multi-input single-output (MISO) wireless powered communication network (WPCN) under the protocol of harvest-then-transmit. The power station (PS) with reliable power supply can replenish the passive user nodes by wireless power transfer (WPT) in the downlink (DL), then each user node transmits independent information to the sink by a time division multiple access (TDMA) scheme in the uplink (UL). We consider the joint time allocation and beamforming design to maximize the system sum-throughput. The semidefinite relaxation (SDR) technique is applied to solve the nonconvex design problem. The tightness of SDR approximation, thus the global optimality, is proved. This implies that only one single energy beamformer is required at the PS. Then a fast semiclosed form solution is proposed by exploiting the inherent structure. Simulation results demonstrate the efficiency of the proposed algorithms from the perspectives of time complexity and information throughput.

Connected through hyperedge HE-1 (induced by source paper "wirelessly powered sensor networks power allocation for channel estimation and energy beamforming"):
  with members:
    - "cluster based wireless energy transfer for low complex energy receivers"
    - "wireless energy beamforming using received signal strength indicator feedback"
    - "on the beneficial roles of fading and transmit diversity in wireless power transfer with nonlinear energy harvesting"
    - "waveform design for wireless power transfer with limited feedback"
    - "distributed wireless power transfer with energy feedback"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "on the feasibility of wireless energy transfer using massive antenna arrays"
    - "waveform design for wireless power transfer"

Connected through hyperedge HE-2 (induced by source paper "transmission delay minimization in wireless powered communication systems"):
  with members:
    - "power allocation and effective capacity of af successive relays"
    - "optimization and analysis of wireless powered multi antenna cooperative systems"
    - "cross layer optimization for ultra reliable and low latency radio access networks"
    - "wireless powered dual hop multi antenna relaying systems impact of csi and antenna correlation"
    - "effective capacity of receive antenna selection mimo ostbc systems in co channel interference"
    - "wireless charging technologies fundamentals standards and network applications"
    - "wireless powered communication networks an overview"
    - "some new research trends in wirelessly powered communications"

Connected through hyperedge HE-3 (induced by source paper "optimal beamforming and time allocation for partially wireless powered sensor networks with downlink swipt"):
  with members:
    - "wireless charging technologies fundamentals standards and network applications"
    - "wireless powered communication networks an overview"
    - "cognitive wireless powered network spectrum sharing models and throughput maximization"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "spatial throughput maximization of wireless powered communication networks"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "multi antenna wireless powered communication with energy beamforming"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"

Connected through hyperedge HE-4 (induced by source paper "maximizing ergodic throughput in wireless powered communication networks"):
  with members:
    - "beamforming optimization for full duplex wireless powered mimo systems"
    - "wireless power meets energy harvesting a joint energy allocation approach in ofdm based system"
    - "wireless powered communication networks an overview"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "optimized training design for wireless energy transfer"
    - "throughput maximization in wireless powered communication networks"
    - "energy efficient optimization for wireless information and power transfer in large scale mimo systems employing energy beamforming"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-5 (induced by source paper "on maximizing sampling time of rf harvesting sensor nodes over random channel gains"):
  with members:
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "powering the next billion devices with wi fi"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "throughput maximization in wireless powered communication networks"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "multi antenna wireless powered communication with energy beamforming"

Connected through hyperedge HE-6 (induced by source paper "joint beamforming and power splitting control in downlink cooperative swipt noma systems"):
  with members:
    - "a minorization maximization method for optimizing sum rate in the downlink of non orthogonal multiple access systems"
    - "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"
    - "the application of mimo to non orthogonal multiple access"
    - "wireless information and energy transfer in multi antenna interference channel"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "delay optimal data forwarding in vehicular sensor networks"

Connected through hyperedge HE-7 (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"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"

Connected through hyperedge HE-8 (induced by source paper "wireless power meets energy harvesting a joint energy allocation approach in ofdm based system"):
  with members:
    - "wireless powered communication opportunities and challenges"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "spatial throughput maximization of wireless powered communication networks"
    - "optimized training for net energy maximization in multi antenna wireless energy transfer over frequency selective channel"
    - "user cooperation in wireless powered communication networks"
    - "optimal resource allocation in full duplex wireless powered communication network"
    - "energy beamforming with one bit feedback"
    - "full duplex wireless powered relay with self energy recycling"

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)