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: "physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"
  Abstract: Consider transceiver designs in a multiuser multi-input single-output (MISO) downlink channel, where the users are to receive the same data stream simultaneously. This problem, known as physical-layer multicasting, has drawn much interest. Presently, a popularized approach is transmit beamforming, in which the beamforming optimization is handled by a rank-one approximation method called semidefinite relaxation (SDR). SDR-based beamforming has been shown to be promising for a small or moderate number of users. This paper describes two new transceiver strategies for physical-layer multicasting. The first strategy, called stochastic beamforming (SBF), randomizes the beamformer in a per-symbol time-varying manner, so that the rank-one approximation in SDR can be bypassed. We propose several efficiently realizable SBF schemes, and prove that their multicast achievable rate gaps with respect to the MISO multicast capacity must be no worse than 0.8314 bits/s/Hz, irrespective of any other factors such as the number of users. The use of channel coding and the assumption of sufficiently long code lengths play a crucial role in achieving the above result. The second strategy combines transmit beamforming and the Alamouti space-time code. The result is a rank-two generalization of SDR-based beamforming. We show by analysis that this SDR-based beamformed Alamouti scheme has a better worst-case effective signal-to-noise ratio (SNR) scaling, and hence a better multicast rate scaling, than SDR-based beamforming. We further the work by combining SBF and the beamformed Alamouti scheme, wherein an improved constant rate gap of 0.39 bits/s/Hz is proven. Simulation results show that under a channel-coded, many-user setting, the proposed multicast transceiver schemes yield significant SNR gains over SDR-based beamforming at the same bit error rate level.

Connected through hyperedge HE-1 (induced by source paper "robust transmissions in wireless powered multi relay networks with chance interference constraints"):
  with members:
    - "optimization of a power splitting protocol for two way multiple energy harvesting relay system"
    - "from d2d to ds2d prolonging the battery life of mobile devices via ds2d communications"
    - "an overview of sustainable green 5g networks"
    - "separation framework an enabler for cooperative and d2d communication for future 5g networks"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "multiuser mimo wireless energy transfer with coexisting opportunistic communication"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "distributed resource allocation for relay aided device to device communication a message passing approach"

Connected through hyperedge HE-2 (induced by source paper "symbol level and multicast precoding for multiuser multiantenna downlink a survey classification and challenges"):
  with members:
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "an overview on resource allocation techniques for multi user mimo systems"
    - "spatio temporal waveform design for multiuser massive mimo downlink with 1 bit receivers"
    - "joint beamforming and broadcasting in massive mimo"
    - "coordinate update algorithms for robust power loading for the mu miso downlink with outage constraints"
    - "energy efficient symbol level precoding in multiuser miso based on relaxed detection region"
    - "robust transmission in downlink multiuser miso systems a rate splitting approach"
    - "adaptive pilot clustering in heterogeneous massive mimo networks"

Connected through hyperedge HE-3 (induced by source paper "physical layer service integration in 5g potentials and challenges"):
  with members:
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "an overview of sustainable green 5g networks"
    - "gsvd based precoding in mimo systems with integrated services"
    - "robust artificial noise aided transmit design for multi user miso systems with integrated services"
    - "wireless powered communication opportunities and challenges"
    - "multi antenna relay aided wireless physical layer security"
    - "enhancing wireless information and power transfer by exploiting multi antenna techniques"
    - "simultaneous wireless information and power transfer in modern communication systems"

Connected through hyperedge HE-4 (induced by source paper "artificial noise aided biobjective transmitter optimization for service integration in multi user mimo broadcast channel"):
  with members:
    - "gsvd based precoding in mimo systems with integrated services"
    - "robust artificial noise aided transmit design for multi user miso systems with integrated services"
    - "what will 5g be"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "spatially selective artificial noise aided transmit optimization for miso multi eves secrecy rate maximization"
    - "wireless physical layer security with imperfect channel state information a survey"
    - "new results on multiple input multiple output broadcast channels with confidential messages"
    - "precoder design for physical layer multicasting"

Connected through hyperedge HE-5 (induced by source paper "reel bf design achieving the sdp bound for downlink beamforming with arbitrary shaping constraints"):
  with members:
    - "rank two beamforming and power allocation in multicasting relay networks"
    - "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"
    - "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-6 (induced by source paper "reducing the computational complexity of multicasting in large scale antenna systems"):
  with members:
    - "energy efficient downlink transmission for multicell massive das with pilot contamination"
    - "a robust design for miso physical layer multicasting over line of sight channels"
    - "multicast multigroup beamforming for per antenna power constrained large scale arrays"
    - "massive mimo multicasting in noncooperative cellular networks"
    - "what will 5g be"
    - "weighted fair multicast multigroup beamforming under per antenna power constraints"
    - "waveform design for secure siso transmissions and multicasting"
    - "coordinated multicast beamforming in multicell networks"

Connected through hyperedge HE-7 (induced by source paper "unraveling the rank one solution mystery of robust miso downlink transmit optimization a verifiable sufficient condition via a new duality result"):
  with members:
    - "coordinate update algorithms for robust power loading for the mu miso downlink with outage constraints"
    - "a parallel decomposition method for nonconvex stochastic multi agent optimization problems"
    - "a stochastic beamformed amplify and forward scheme in a multigroup multicast mimo relay network with per antenna power constraints"
    - "optimal multiuser transmit beamforming a difficult problem with a simple solution structure"
    - "distributed robust multicell coordinated beamforming with imperfect csi an admm approach"
    - "worst case robust multiuser transmit beamforming using semidefinite relaxation duality and implications"
    - "robust linear precoder design for multi cell downlink transmission"
    - "outage constrained robust transmit optimization for multiuser miso downlinks tractable approximations by conic optimization"

Connected through hyperedge HE-8 (induced by source paper "capacity of uav enabled multicast channel joint trajectory design and power allocation"):
  with members:
    - "placement optimization of uav mounted mobile base stations"
    - "uav enabled wireless power transfer trajectory design and energy region characterization"
    - "trajectory optimization for completion time minimization in uav enabled multicasting"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "efficient deployment of multiple unmanned aerial vehicles for optimal wireless coverage"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "coordinated multicast beamforming in multicell networks"

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)