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: "joint scheduling and arq for mu mimo downlink in the presence of inter cell interference"
  Abstract: User scheduling and multiuser multi-antenna (MU-MIMO) transmission are at the core of high-rate data-oriented downlink schemes of the next-generation of cellular systems (e.g., LTE-Advanced). Scheduling selects groups of users according to their channels vector directions and SINR levels. However, when scheduling is applied independently in each cell, the inter-cell interference (ICI) power at each user receiver is not known in advance since it changes at each new scheduling slot depending on the scheduling decisions of all interfering base stations. In order to cope with this uncertainty, we consider the joint operation of scheduling, MU-MIMO beamforming and Automatic Repeat reQuest (ARQ). We develop a game-theoretic framework for this problem and build on stochastic optimization techniques in order to find optimal scheduling and ARQ schemes. Particularizing our framework to the case of "outage service rates", we obtain a scheme based on adaptive variable-rate coding at the physical layer, combined with ARQ at the Logical Link Control (ARQ-LLC). Then, we present a novel scheme based on incremental redundancy Hybrid ARQ (HARQ) that is able to achieve a throughput performance arbitrarily close to the "genie-aided service rates", with no need for a genie that provides non-causally the ICI power levels. The novel HARQ scheme is both easier to implement and superior in performance with respect to the conventional combination of adaptive variable-rate coding and ARQ-LLC.

Connected through hyperedge HE-1 (induced by source paper "pilot contamination mitigation with reduced rf chains"):
  with members:
    - "hybrid analog digital beamforming for massive mimo systems"
    - "partially connected hybrid precoding in mm wave systems with dynamic phase shifter networks"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"
    - "smart pilot assignment for massive mimo"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "pilot beam pattern design for channel estimation in massive mimo systems"
    - "what will 5g be"

Connected through hyperedge HE-2 (induced by source paper "an overview on resource allocation techniques for multi user mimo systems"):
  with members:
    - "low complexity downlink user selection for massive mimo systems"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "user association in 5g networks a survey and an outlook"
    - "cell free massive mimo versus small cells"
    - "mu mimo mac protocols for wireless local area networks a survey"
    - "on the number of rf chains and phase shifters and scheduling design with hybrid analog digital beamforming"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"

Connected through hyperedge HE-3 (induced by source paper "second order statistics of mimo rayleigh interference channels theory applications and analysis"):
  with members:
    - "multiuser scheduling in a markov modeled downlink using randomly delayed arq feedback"

Connected through hyperedge HE-4 (induced by source paper "network control without csi using rateless codes for downlink cellular systems"):
  with members:
    - "de randomizing shannon the design and analysis of a capacity achieving rateless code"
    - "joint scheduling and resource allocation in ofdma downlink systems via ack nak feedback"
    - "asymptotically optimal downlink scheduling over markovian fading channels"
    - "rateless coding for gaussian channels"

Connected through hyperedge HE-5 (induced by source paper "exploiting hybrid channel information for downlink multi user mimo scheduling"):
  with members:
    - "precoder design for physical layer multicasting"
    - "on the degrees of freedom of time correlated miso broadcast channel with delayed csit"
    - "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 "diversity backpressure scheduling and routing with mutual information accumulation in wireless ad hoc networks"):
  with members:
    - "cooperative routing in wireless networks using mutual information accumulation"

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)