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: "spatial domain simultaneous information and power transfer for mimo channels"
  Abstract: In this paper, we theoretically investigate a new technique for simultaneous information and power transfer (SWIPT) in multiple-input multiple-output (MIMO) point-to-point with radio frequency energy harvesting capabilities. The proposed technique exploits the spatial decomposition of the MIMO channel and uses the eigenchannels either to convey information or to transfer energy. In order to generalize our study, we consider channel estimation error in the decomposition process and the interference between the eigenchannels. An optimization problem that minimizes the total transmitted power subject to maximum power per eigenchannel, information and energy constraints is formulated as a mixed-integer nonlinear program and solved to optimality using mixed-integer second-order cone programming. A near-optimal mixed-integer linear programming solution is also developed with robust computational performance. A polynomial complexity algorithm is further proposed for the optimal solution of the problem when no maximum power per eigenchannel constraints are imposed. In addition, a low polynomial complexity algorithm is developed for the power allocation problem with a given eigenchannel assignment, as well as a low-complexity heuristic for solving the eigenchannel assignment problem.

Connected through hyperedge HE-1 (induced by source paper "transmit precoding and receive power splitting for harvested power maximization in mimo swipt systems"):
  with members:
    - "jointly optimal spatial channel assignment and power allocation for mimo swipt systems"
    - "harvested power maximization in qos constrained mimo swipt with generic rf harvesting model"
    - "power allocation and scheduling for swipt systems with non linear energy harvesting model"
    - "weighted sum transmit power minimization for full duplex system with swipt and self energy recycling"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "joint transmit beamforming and receive power splitting for miso swipt systems"
    - "relaying protocols for wireless energy harvesting and information processing"

Connected through hyperedge HE-2 (induced by source paper "jointly optimal spatial channel assignment and power allocation for mimo swipt systems"):
  with members:
    - "harvested power maximization in qos constrained mimo swipt with generic rf harvesting model"
    - "joint optimization of power and data transfer in multiuser mimo systems"
    - "joint antenna selection and spatial switching for energy efficient mimo swipt system"
    - "hybrid beamforming for massive mimo a survey"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

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"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"

Connected through hyperedge HE-4 (induced by source paper "joint antenna selection and spatial switching for energy efficient mimo swipt system"):
  with members:
    - "stochastic geometric analysis of energy efficient dense cellular networks"
    - "energy efficient heterogeneous cellular networks with spectrum underlay and overlay access"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "evolution toward 5g multi tier cellular wireless networks an interference management perspective"
    - "wireless information and power transfer in multiuser ofdm systems"
    - "relaying protocols for wireless energy harvesting and information processing"

Connected through hyperedge HE-5 (induced by source paper "multipair two way relay network with harvest then transmit users resolving pairwise uplink downlink coupling"):
  with members:
    - "rank two beamforming and power allocation in multicasting relay networks"
    - "on the efficiency of far field wireless power transfer"
    - "joint beamforming optimization and power control for full duplex mimo two way relay channel"
    - "joint transceiver and power splitter design over two way relaying channel with lattice codes and energy harvesting"
    - "secure and green swipt in distributed antenna networks with limited backhaul capacity"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "beamforming for miso interference channels with qos and rf energy transfer"
    - "physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"

Connected through hyperedge HE-6 (induced by source paper "path following algorithms for beamforming and signal splitting in rf energy harvesting networks"):
  with members:
    - "resource allocation in wireless networks with rf energy harvesting and transfer"
    - "enhancing wireless information and power transfer by exploiting multi antenna techniques"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "relaying protocols for wireless energy harvesting and information processing"

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)