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: "multi user diversity vs accurate channel state information in mimo downlink channels"
  Abstract: In a multiple transmit antenna, single antenna per receiver downlink channel with limited channel state feedback, we consider the following question: given a constraint on the total system-wide feedback load, is it preferable to get low-rate/coarse channel feedback from a large number of receivers or high-rate/high-quality feedback from a smaller number of receivers? Acquiring feedback from many receivers allows multi-user diversity to be exploited, while high-rate feedback allows for very precise selection of beamforming directions. We show that there is a strong preference for obtaining high-quality feedback, and that obtaining near-perfect channel information from as many receivers as possible provides a significantly larger sum rate than collecting a few feedback bits from a large number of users. In terms of system design, this corresponds to a preference for acquiring high-quality feedback from a few users on each time-frequency resource block, as opposed to coarse feedback from many users on each block.

Connected through hyperedge HE-1 (induced by source paper "delay performance of the multiuser miso downlink under imperfect csi and finite length coding"):
  with members:
    - "delay performance of multi antenna multicasting in wireless networks"
    - "delay performance of the multiuser miso downlink"
    - "delay performance of miso wireless communications"
    - "analysis of wireless communications with finite blocklength and imperfect channel knowledge"
    - "the dispersion of nearest neighbor decoding for additive non gaussian channels"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"
    - "effects of channel aging in massive mimo systems"
    - "multi mode transmission for the mimo broadcast channel with imperfect channel state information"

Connected through hyperedge HE-2 (induced by source paper "cooperative limited feedback design for massive machine type communications"):
  with members:
    - "advanced quantizer designs for fdd based fd mimo systems using uniform planar arrays"
    - "exploiting trust degree for multiple antenna user cooperation"
    - "antenna grouping based feedback compression for fdd based massive mimo systems"
    - "five disruptive technology directions for 5g"
    - "interference alignment through user cooperation for two cell mimo interfering broadcast channels"
    - "antenna combining for the mimo downlink channel"

Connected through hyperedge HE-3 (induced by source paper "delay performance of the multiuser miso downlink"):
  with members:
    - "delay performance of wireless communications with imperfect csi and finite length coding"
    - "analysis of wireless communications with finite blocklength and imperfect channel knowledge"
    - "multi mode transmission for the mimo broadcast channel with imperfect channel state information"
    - "mimo wireless communications under statistical queueing constraints"

Connected through hyperedge HE-4 (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-5 (induced by source paper "uplink downlink rate balancing in cooperating cellular networks"):
  with members:
    - "a lower bound on the data rate of dirty paper coding in general noise and interference"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "fundamental limits of cooperation"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"
    - "massive mimo how many antennas do we need"
    - "bounds on the capacity of ofdm underspread frequency selective fading channels"
    - "completely stale transmitter channel state information is still very useful"
    - "interference alignment with analog channel state feedback"

Connected through hyperedge HE-6 (induced by source paper "antenna grouping based feedback compression for fdd based massive mimo systems"):
  with members:
    - "pilot beam pattern design for channel estimation in massive mimo systems"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"
    - "statistical estimation of block sparse time varying signals from multiple measurement vectors"
    - "bounds on eigenvalues of a spatial correlation matrix"
    - "kronecker product correlation model and limited feedback codebook design in a 3d channel model"
    - "downlink training techniques for fdd massive mimo systems open loop and closed loop training with memory"
    - "noncoherent trellis coded quantization a practical limited feedback technique for massive mimo systems"
    - "effects of channel aging in massive mimo systems"

Connected through hyperedge HE-7 (induced by source paper "joint wireless information and energy transfer with reduced feedback in mimo interference channels"):
  with members:
    - "simultaneous information and power transfer for broadband wireless systems"
    - "wireless information and power transfer in multiuser ofdm systems"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "optimal scheduling and power allocation for two hop energy harvesting communication systems"
    - "wireless information transfer with opportunistic energy harvesting"
    - "enabling wireless power transfer in cellular networks architecture modeling and deployment"
    - "robust beamforming for wireless information and power transmission"
    - "tree structured random vector quantization for limited feedback wireless channels"

Connected through hyperedge HE-8 (induced by source paper "optimal feedback rate sharing strategy in zero forcing mimo broadcast channels"):
  with members:
    - "an analytical framework for heterogeneous partial feedback design in heterogeneous multicell ofdma networks"
    - "random beamforming with heterogeneous users and selective feedback individual sum rate and individual scaling laws"
    - "stochastic control of event driven feedback in multiantenna interference channels"
    - "a scalable limited feedback design for network mimo using per cell product codebook"
    - "mode switching for the multi antenna broadcast channel based on delay and channel quantization"
    - "adaptive limited feedback for sum rate maximizing beamforming in cooperative multicell systems"
    - "limited feedback based block diagonalization for the mimo broadcast channel"
    - "antenna combining for the mimo downlink channel"

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)