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: "multi antenna wireless energy transfer for backscatter communication systems"
  Abstract: We study RF-enabled wireless energy transfer (WET) via energy beamforming, from a multi-antenna energy transmitter (ET) to multiple energy receivers (ERs) in a backscatter communication system, such as RFID, where each ER (or RFID tag) reflects back a portion of the incident signal to the ET (or RFID reader). For such a system, the acquisition of the forward-channel (i.e., ET-to-ER) state information (F-CSI) at the ET is challenging, since the ERs are typically too energy-and-hardware-constrained to estimate or feed back the F-CSI. The ET leverages its observed backscatter signals to estimate the backscatter-channel (i.e., ET-to-ER-to-ET) state information (BS-CSI) directly. We first analyze the harvested energy obtained by using the estimated BS-CSI. Furthermore, we optimize the channel-training energy and the energy allocation weights for different energy beams, for weighted-sum-energy (WSE) maximization and proportional-fair-energy (PFE) maximization. For WET to single ER, we obtain the optimal channel-training energy in a semi-closed form. For WET to multiple ERs, the optimal WET scheme for WSE maximization is shown to use only one energy beam. For PFE maximization, we show it is a biconvex problem, and propose a block-coordinate-descent based algorithm to find the close-to-optimal solution. Numerical results show that with the optimized solutions, the harvested energy suffers slight reduction of less than 10%, compared to that obtained by using the perfect F-CSI. Hence, energy beamforming by using the estimated BS-CSI is promising, as the complexity and energy requirement is shifted from the ERs to the ET.

Connected through hyperedge HE-1 (induced by source paper "energy efficient uav backscatter communication with joint trajectory design and resource optimization"):
  with members:
    - "sum throughput maximization in multi tag backscattering to multiantenna reader"
    - "large intelligent surface antennas lisa making reflective radios smart"
    - "uav data collection over noma backscatter networks uav altitude and trajectory optimization"
    - "cooperative ambient backscatter communications for green internet of things"
    - "symbiotic radio a new communication paradigm for passive internet of things"
    - "energy minimization for wireless communication with rotary wing uav"
    - "spectrum sharing for internet of things a survey"
    - "throughput maximization for uav enabled wireless powered communication networks"

Connected through hyperedge HE-2 (induced by source paper "design of ambient backscatter training for retrodirective wireless power transfer"):
  with members:
    - "retrodirective large antenna energy beamforming in backscatter multi user networks"
    - "retrodirective multi user wireless power transfer with massive mimo"
    - "next generation backscatter communication systems techniques and applications"
    - "ambient backscatter communications a contemporary survey"
    - "modulation in the air backscatter communication over ambient ofdm carrier"
    - "inter technology backscatter towards internet connectivity for implanted devices"
    - "communications and signals design for wireless power transmission"
    - "wireless powered communication opportunities and challenges"

Connected through hyperedge HE-3 (induced by source paper "reusing wireless power transfer for backscatter assisted relaying in wpcns"):
  with members:
    - "backscatter assisted relaying in wireless powered communications network"
    - "deep reinforcement learning for online computation offloading in wireless powered mobile edge computing networks"
    - "joint tx power allocation and rx power splitting for swipt system with multiple nonlinear energy harvesting circuits"
    - "multi antenna enabled cluster based cooperation in wireless powered communication networks"
    - "distributed scheduling in wireless powered communication network protocol design and performance analysis"
    - "ambient backscatter communications a contemporary survey"
    - "user cooperation for enhanced throughput fairness in wireless powered communication networks"
    - "distributed charging control in broadband wireless power transfer networks"

Connected through hyperedge HE-4 (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"
    - "waveform optimization for swipt with nonlinear energy harvester modeling"
    - "wireless powered communication opportunities and challenges"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "simultaneous wireless information and power transfer in a two user ofdm interference channel"

Connected through hyperedge HE-5 (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"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"

Connected through hyperedge HE-6 (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"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"

Connected through hyperedge HE-7 (induced by source paper "energy beamforming for wireless information and power transfer in backscatter multiuser networks"):
  with members:
    - "optimization of power transfer efficiency and energy efficiency for wireless powered systems with massive mimo"
    - "beamforming design for max min fair swipt in green cloud ran with wireless fronthaul"
    - "modulation in the air backscatter communication over ambient ofdm carrier"
    - "wirelessly powered backscatter communication networks modeling coverage and capacity"
    - "throughput optimization for massive mimo systems powered by wireless energy transfer"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-8 (induced by source paper "optimal channel estimation for reciprocity based backscattering with a full duplex mimo reader"):
  with members:
    - "lora backscatter enabling the vision of ubiquitous connectivity"
    - "modulation in the air backscatter communication over ambient ofdm carrier"
    - "communications and signals design for wireless power transmission"
    - "semi coherent detection and performance analysis for ambient backscatter system"

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)