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: "stability and delay of zero forcing sdma with limited feedback"
  Abstract: This paper addresses the stability and queueing delay of Space Division Multiple Access (SDMA) systems with bursty traffic, where zero-forcing beamforming enables simultaneous transmission to multiple mobiles. Computing beamforming vectors relies on quantized channel state information (CSI) feedback (limited feedback) from mobiles. Define the stability region for SDMA as the set of multiuser packet-arrival rates for which the steady-state queue lengths are finite. Given perfect CSI feedback and equal power allocation over scheduled queues, the stability region is proved to be a convex polytope having the derived vertices. For any set of arrival rates in the stability region, multiuser queues are shown to be stabilized by a joint queue-and-beamforming control policy that maximizes the departure-rate-weighted sum of queue lengths. The stability region for limited feedback is found to be the perfect-CSI region multiplied by one minus a small factor. The required number of feedback bits per mobile is proved to scale logarithmically with the inverse of the above factor as well as linearly with the number of transmit antennas minus one. The effects of limited feedback on queueing delay are also quantified. For Poisson arrival processes, CSI quantization errors are shown to multiply average queueing delay by a factor larger than one. This factor can be controlled by adjusting the number of feedback bits per mobile following the derived relationship. For general arrival processes, CSI errors are found to increase Kingman's bound on the tail probability of the instantaneous delay by one plus a small factor. The required number of feedback bits per mobile is shown to scale logarithmically with this factor.

Connected through hyperedge HE-1 (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-2 (induced by source paper "on the benefits of edge caching for mimo interference alignment"):
  with members:
    - "optimal geographic caching in cellular networks"
    - "hierarchical coded caching"
    - "performance analysis and optimization for interference alignment over mimo interference channels with limited feedback"
    - "device to device data storage with regenerating codes"
    - "what will 5g be"
    - "living on the edge the role of proactive caching in 5g wireless networks"
    - "cache enabled opportunistic cooperative mimo for video streaming in wireless systems"
    - "many to many matching games for proactive social caching in wireless small cell networks"

Connected through hyperedge HE-3 (induced by source paper "queueing stability and csi probing of a tdd wireless network with interference alignment"):
  with members:
    - "performance analysis and optimization for interference alignment over mimo interference channels with limited feedback"
    - "csit sharing over finite capacity backhaul for spatial interference alignment"
    - "performance evaluation of multiterminal backhaul compression for cloud radio access networks"
    - "on feasibility of interference alignment in mimo interference networks"
    - "interference alignment with analog channel state feedback"
    - "interference alignment under limited feedback for mimo interference channels"
    - "interference alignment with limited feedback"
    - "on feasibility of interference alignment in mimo interference networks"

Connected through hyperedge HE-4 (induced by source paper "transmit power minimization in small cell networks under time average qos constraints"):
  with members:
    - "open vs closed access femtocells in the uplink"
    - "dynamic resource allocation in cognitive radio networks"
    - "femto macro cellular interference control with subband scheduling and interference cancelation"
    - "training and feedback optimization for multiuser mimo downlink"
    - "delay optimal power and precoder adaptation for multi stream mimo systems"
    - "on peak versus average interference power constraints for protecting primary users in cognitive radio networks"

Connected through hyperedge HE-5 (induced by source paper "large deviation delay analysis of queue aware multi user mimo systems with two timescale mobile driven feedback"):
  with members:
    - "queue aware dynamic clustering and power allocation for network mimo systems via distributed stochastic learning"
    - "delay sensitive distributed power and transmission threshold control for s aloha network with finite state markov fading channels"
    - "on the user selection for mimo broadcast channels"

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)