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: "precoder design for physical layer multicasting"
  Abstract: This paper studies the instantaneous rate maximization and the weighted sum delay minimization problems over a K-user multicast channel, where multiple antennas are available at the transmitter as well as at all the receivers. Motivated by the degree of freedom optimality and the simplicity offered by linear precoding schemes, we consider the design of linear precoders using the aforementioned two criteria. We first consider the scenario wherein the linear precoder can be any complex-valued matrix subject to rank and power constraints. We propose cyclic alternating ascent based precoder design algorithms and establish their convergence to respective stationary points. Simulation results reveal that our proposed algorithms considerably outperform known competing solutions. We then consider a scenario in which the linear precoder can be formed by selecting and concatenating precoders from a given finite codebook of precoding matrices, subject to rank and power constraints. We show that under this scenario, the instantaneous rate maximization problem is equivalent to a robust submodular maximization problem which is strongly NP hard. We propose a deterministic approximation algorithm and show that it yields a bicriteria approximation. For the weighted sum delay minimization problem we propose a simple deterministic greedy algorithm, which at each step entails approximately maximizing a submodular set function subject to multiple knapsack constraints, and establish its performance guarantee.

Connected through hyperedge HE-1 (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"
    - "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"
    - "wireless physical layer security with imperfect channel state information a survey"
    - "new results on multiple input multiple output broadcast channels with confidential messages"

Connected through hyperedge HE-2 (induced by source paper "robust artificial noise aided transmit design for multi user miso systems with integrated services"):
  with members:
    - "safeguarding decentralized wireless networks using full duplex jamming receivers"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"
    - "wireless physical layer security with imperfect channel state information a survey"
    - "outage constrained robust secure transmission for miso wiretap channels"
    - "new results on multiple input multiple output broadcast channels with confidential messages"
    - "robust secure transmission in miso channels based on worst case optimization"
    - "optimal and robust transmit designs for miso channel secrecy by semidefinite programming"

Connected through hyperedge HE-3 (induced by source paper "coordinated multicasting with opportunistic user selection in multicell wireless systems"):
  with members:
    - "sum rate maximizing multigroup multicast beamforming under per antenna power constraints"
    - "weighted fair multicast multigroup beamforming under per antenna power constraints"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"
    - "coordinated multicast beamforming in multicell networks"

Connected through hyperedge HE-4 (induced by source paper "massive mimo multicasting in noncooperative cellular networks"):
  with members:
    - "massive mimo for next generation wireless systems"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "coordinated multicast beamforming in multicell networks"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "cooperative interference management with miso beamforming"

Connected through hyperedge HE-5 (induced by source paper "exploiting hybrid channel information for downlink multi user mimo scheduling"):
  with members:
    - "on the degrees of freedom of time correlated miso broadcast channel with delayed csit"
    - "joint scheduling and arq for mu mimo downlink in the presence of inter cell interference"
    - "multi user mimo with outdated csi training feedback and scheduling"
    - "completely stale transmitter channel state information is still very useful"
    - "mimo downlink scheduling with non perfect channel state knowledge"
    - "multiuser mimo achievable rates with downlink training and channel state feedback"

Connected through hyperedge HE-6 (induced by source paper "physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"):
  with members:
    - "achievable rate derivations and further simulation results for physical layer multicasting by stochastic transmit beamforming and alamouti space time coding"
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"

Connected through hyperedge HE-7 (induced by source paper "decomposition by successive convex approximation a unifying approach for linear transceiver design in heterogeneous networks"):
  with members:
    - "signal processing and optimal resource allocation for the interference channel"
    - "parallel selective algorithms for big data optimization"
    - "decomposition by partial linearization parallel optimization of multi agent systems"
    - "base station activation and linear transceiver design for optimal resource management in heterogeneous networks"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"
    - "linear transceiver design for a mimo interfering broadcast channel achieving max min fairness"
    - "linear precoding in cooperative mimo cellular networks with limited coordination clusters"
    - "balancing egoism and altruism on the interference channel the mimo case"

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)