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: "throughput optimization for massive mimo systems powered by wireless energy transfer"
  Abstract: This paper studies a wireless-energy-transfer (WET) enabled massive multiple-input-multiple-output (MIMO) system (MM) consisting of a hybrid data-and-energy access point (H-AP) and multiple single-antenna users. In the WET-MM system, the H-AP is equipped with a large number    $M$   of antennas and functions like a conventional AP in receiving data from users, but additionally supplies wireless power to the users. We consider frame-based transmissions. Each frame is divided into three phases: the uplink channel estimation (CE) phase, the downlink WET phase, as well as the uplink wireless information transmission (WIT) phase. Firstly, users use a fraction of the previously harvested energy to send pilots, while the H-AP estimates the uplink channels and obtains the downlink channels by exploiting channel reciprocity. Next, the H-AP utilizes the channel estimates just obtained to transfer wireless energy to all users in the downlink via energy beamforming. Finally, the users use a portion of the harvested energy to send data to the H-AP simultaneously in the uplink (reserving some harvested energy for sending pilots in the next frame) . To optimize the throughput and ensure rate fairness, we consider the problem of maximizing the minimum rate among all users. In the large-    $M$   regime, we obtain the asymptotically optimal solutions and some interesting insights for the optimal design of WET-MM system.

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 "learning and fairness in energy harvesting a maximin multi armed bandits approach"):
  with members:
    - "distributed user association in energy harvesting dense small cell networks a mean field multi armed bandit approach"
    - "online learning schemes for power allocation in energy harvesting communications"
    - "energy harvesting wireless communications a review of recent advances"
    - "user cooperation in wireless powered communication networks"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-3 (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-4 (induced by source paper "joint active and passive beamforming optimization for intelligent reflecting surface assisted swipt under qos constraints"):
  with members:
    - "secure wireless communication via intelligent reflecting surface"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "intelligent reflecting surface meets ofdm protocol design and rate maximization"
    - "passive beamforming and information transfer via large intelligent surface"
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "weighted sum power maximization for intelligent reflecting surface aided swipt"
    - "intelligent reflecting surface assisted secrecy communication via joint beamforming and jamming"

Connected through hyperedge HE-5 (induced by source paper "an energy efficient controller for wirelessly powered communication networks"):
  with members:
    - "swipt using hybrid arq over time varying channels"
    - "optimal and near optimal policies for wireless power transfer in energy limited and power limited scenarios"
    - "joint sum rate and error probability optimization finite blocklength analysis"
    - "joint transfer of energy and information in a two hop relay channel"
    - "optimal energy and data routing in networks with energy cooperation"
    - "battery powered devices in wpcns"
    - "wireless powered relaying with finite block length codes"
    - "on wireless energy and information transfer in relay networks"

Connected through hyperedge HE-6 (induced by source paper "sum throughput maximization in multi tag backscattering to multiantenna reader"):
  with members:
    - "optimal channel estimation for reciprocity based backscattering with a full duplex mimo reader"
    - "cooperative ambient backscatter communications for green internet of things"
    - "fractional programming for communication systems part i power control and beamforming"
    - "retrodirective large antenna energy beamforming in backscatter multi user networks"
    - "transmit precoding and receive power splitting for harvested power maximization in mimo swipt systems"
    - "max min sinr in large scale single cell mu mimo asymptotic analysis and low complexity transceivers"
    - "inference from randomized transmissions by many backscatter sensors"
    - "multi antenna wireless energy transfer for backscatter communication systems"

Connected through hyperedge HE-7 (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"
    - "spatial throughput maximization of wireless powered communication networks"
    - "joint beamforming design and time allocation for 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-8 (induced by source paper "multi tag backscattering to mimo reader channel estimation and throughput fairness"):
  with members:
    - "sum throughput maximization in multi tag backscattering to multiantenna reader"
    - "optimal channel estimation for reciprocity based backscattering with a full duplex mimo reader"
    - "multiuser wirelessly powered backscatter communications nonlinearity waveform design and sinr energy tradeoff"
    - "retrodirective large antenna energy beamforming in backscatter multi user networks"
    - "inference from randomized transmissions by many backscatter sensors"
    - "backscatter multiplicative multiple access systems fundamental limits and practical design"
    - "ambient backscatter communications a contemporary survey"
    - "multi antenna wireless energy transfer for backscatter communication systems"

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)