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: "rank two beamforming and power allocation in multicasting relay networks"
  Abstract: In this paper, we propose a novel single-group multicasting relay beamforming scheme. We assume a source that transmits common messages via multiple amplify-and-forward relays to multiple destinations. To increase the number of degrees of freedom in the beamforming design, the relays process two received signals jointly and transmit the Alamouti space-time block code over two different beams. Furthermore, in contrast to the existing relay multicasting scheme of the literature, we take into account the direct links from the source to the destinations. We aim to maximize the lowest received quality-of-service by choosing the proper relay weights and the ideal distribution of the power resources in the network. To solve the corresponding optimization problem, we propose an iterative algorithm which solves sequences of convex approximations of the original non-convex optimization problem. Simulation results demonstrate significant performance improvements of the proposed methods as compared with the existing relay multicasting scheme of the literature and an algorithm based on the popular semidefinite relaxation technique.

Connected through hyperedge HE-1 (induced by source paper "reel bf design achieving the sdp bound for downlink beamforming with arbitrary shaping constraints"):
  with members:
    - "general rank multiuser downlink beamforming with shaping constraints using real valued ostbc"
    - "optimal multiuser transmit beamforming a difficult problem with a simple solution structure"
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"
    - "spatially selective artificial noise aided transmit optimization for miso multi eves secrecy rate maximization"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "outage constrained robust transmit optimization for multiuser miso downlinks tractable approximations by conic optimization"
    - "secure transmission with artificial noise over fading channels achievable rate and optimal power allocation"

Connected through hyperedge HE-2 (induced by source paper "multipair two way relay network with harvest then transmit users resolving pairwise uplink downlink coupling"):
  with members:
    - "on the efficiency of far field wireless power transfer"
    - "joint beamforming optimization and power control for full duplex mimo two way relay channel"
    - "spatial domain simultaneous information and power transfer for mimo channels"
    - "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-3 (induced by source paper "content centric sparse multicast beamforming for cache enabled cloud ran"):
  with members:
    - "cellular broadcast service convergence through caching for comp cloud rans"
    - "content centric multicast beamforming in cache enabled cloud radio access networks"
    - "on content centric wireless delivery networks"
    - "backhaul limited asymmetric cooperation for mimo cellular networks via semidefinite relaxation"
    - "caching eliminates the wireless bottleneck in video aware wireless networks"
    - "weighted fair multicast multigroup beamforming under per antenna power constraints"
    - "living on the edge the role of proactive caching in 5g wireless networks"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"

Connected through hyperedge HE-4 (induced by source paper "semidefinite relaxation and approximation analysis of a beamformed alamouti scheme for relay beamforming networks"):
  with members:
    - "some proof derivations and further simulation results for semidefinite relaxation and approximation analysis of a beamformed alamouti scheme for relay beamforming networks"
    - "multicast multigroup beamforming for per antenna power constrained large scale arrays"
    - "a stochastic beamformed amplify and forward scheme in a multigroup multicast mimo relay network with per antenna power constraints"
    - "physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"
    - "group sparse beamforming for green cloud ran"
    - "mimo broadcasting for simultaneous wireless information and power transfer"
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"

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)