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: "airsync enabling distributed multiuser mimo with full spatial multiplexing"
  Abstract: The enormous success of advanced wireless devices is pushing the demand for higher wireless data rates. Denser spectrum reuse through the deployment of more access points per square mile has the potential to successfully meet the increasing demand for more bandwidth. In theory, the best approach to density increase is via distributed multiuser MIMO, where several access points are connected to a central server and operate as a large distributed multi-antenna access point, ensuring that all transmitted signal power serves the purpose of data transmission, rather than creating "interference." In practice, while enterprise networks offer a natural setup in which distributed MIMO might be possible, there are serious implementation difficulties, the primary one being the need to eliminate phase and timing offsets between the jointly coordinated access points. #R##N#In this paper we propose AirSync, a novel scheme which provides not only time but also phase synchronization, thus enabling distributed MIMO with full spatial multiplexing gains. AirSync locks the phase of all access points using a common reference broadcasted over the air in conjunction with a Kalman filter which closely tracks the phase drift. We have implemented AirSync as a digital circuit in the FPGA of the WARP radio platform. Our experimental testbed, comprised of two access points and two clients, shows that AirSync is able to achieve phase synchronization within a few degrees, and allows the system to nearly achieve the theoretical optimal multiplexing gain. We also discuss MAC and higher layer aspects of a practical deployment. To the best of our knowledge, AirSync offers the first ever realization of the full multiuser MIMO gain, namely the ability to increase the number of wireless clients linearly with the number of jointly coordinated access points, without reducing the per client rate.

Connected through hyperedge HE-1 (induced by source paper "distributed base station a concept system for long range broadband wireless access"):
  with members:
    - "a scalable architecture for distributed receive beamforming analysis and experimental demonstration"
    - "high dimensional csi acquisition in massive mimo sparsity inspired approaches"
    - "antenna grouping based feedback compression for fdd based massive mimo systems"
    - "massive mimo for next generation wireless systems"
    - "downlink training techniques for fdd massive mimo systems open loop and closed loop training with memory"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-2 (induced by source paper "indoor massive mimo deployments for uniformly high wireless capacity"):
  with members:
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "massive mimo unlicensed for high performance indoor networks"
    - "enhancing coexistence in the unlicensed band with massive mimo"
    - "massive mimo unlicensed a new approach to dynamic spectrum access"
    - "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
    - "cell free massive mimo versus small cells"
    - "a stochastic analysis of network mimo systems"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"

Connected through hyperedge HE-3 (induced by source paper "mobile lattice coded physical layer network coding with practical channel alignment"):
  with members:
    - "reliable physical layer network coding supporting real applications"
    - "phase precoded compute and forward with partial feedback"
    - "asynchronous convolutional coded physical layer network coding"
    - "multilevel coding schemes for compute and forward with flexible decoding"
    - "scalable synchronization and reciprocity calibration for distributed multiuser mimo"
    - "network coded multiple access"
    - "the degrees of freedom of compute and forward"
    - "physical layer network coding tutorial survey and beyond"

Connected through hyperedge HE-4 (induced by source paper "over the air function computation in sensor networks"):
  with members:
    - "robust analog function computation via wireless multiple access channels"
    - "computing linear functions by linear coding over networks"
    - "communicating the sum of sources over a network"

Connected through hyperedge HE-5 (induced by source paper "consistency in the face of change an adaptive approach to physical layer cooperation"):
  with members:
    - "wireless network information flow a deterministic approach"
    - "design implementation and characterization of a cooperative communications system"
    - "relay subset selection in wireless networks using partial decode and forward transmission"

Connected through hyperedge HE-6 (induced by source paper "network coded multiple access with high order modulations"):
  with members:
    - "on the subtleties of q pam linear physical layer network coding"
    - "coded random access applying codes on graphs to design random access protocols"
    - "uplink non orthogonal multiple access for 5g wireless networks"
    - "network coded multiple access"
    - "constellation mapping for physical layer network coding with m qam modulation"
    - "asynchronous physical layer network coding"
    - "random access with physical layer network coding"
    - "reliable physical layer network coding"

Connected through hyperedge HE-7 (induced by source paper "performance modeling of next generation wireless networks"):
  with members:
    - "an overview of load balancing in hetnets old myths and open problems"
    - "scalable synchronization and reciprocity calibration for distributed multiuser mimo"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "downlink rate distribution in heterogeneous cellular networks under generalized cell selection"
    - "network mimo with linear zero forcing beamforming large system analysis impact of channel estimation and reduced complexity scheduling"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "cost efficient high capacity indoor wireless access denser wi fi or coordinated pico cellular"

Connected through hyperedge HE-8 (induced by source paper "scalable synchronization and reciprocity calibration for distributed multiuser mimo"):
  with members:
    - "network mimo with linear zero forcing beamforming large system analysis impact of channel estimation and reduced complexity scheduling"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"
    - "multiuser miso transmitter optimization for intercell interference mitigation"
    - "femtocell networks a survey"
    - "multiuser mimo achievable rates with downlink training and channel state feedback"

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.NI(Networking and Internet Architecture)