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: "an uplink interference analysis for massive mimo systems with mrc and zf receivers"
  Abstract: This paper considers an uplink cellular system, in which each base station (BS) is equipped with a large number of antennas to serve multiple single-antenna user equipments (UEs) simultaneously. Uplink training with pilot reusing is adopted to acquire the channel state information (CSI) and maximum ratio combining (MRC) or zero forcing (ZF) reception is used for handling multiuser interference. Leveraging stochastic geometry to model the spatial distribution of UEs, we analyze the statistical distributions of the interferences experienced by a typical uplink: intra-cell interference, inter-cell interference and interference due to pilot contamination. For a practical but still large number of BS antennas, a key observation for MRC reception is that it is the intra-cell interference that accounts for the dominant portion of the total interference. In addition, the interference due to pilot contamination tends to have a much wider distribution range than the inter-cell interference when shadowing is strong, although their mean powers are roughly equal. For ZF reception, on the other hand, we observe a significant reduction of the intra-cell interference compared to MRC reception, while the inter-cell interference and the interference due to pilot contamination remains almost the same, thus demonstrating a substantial superiority over MRC reception.

Connected through hyperedge HE-1 (induced by source paper "stochastic geometry based uplink analysis of massive mimo systems with fractional pilot reuse"):
  with members:
    - "johnson mehl cell based analysis of ul cellular network with coupled user and bs locations"
    - "fog massive mimo a user centric seamless hot spot architecture"
    - "massive mimo has unlimited capacity"
    - "modeling and analysis of cellular networks using stochastic geometry a tutorial"
    - "a primer on cellular network analysis using stochastic geometry"
    - "user point processes in cellular networks"
    - "poisson hole process theory and applications to wireless networks"
    - "massive mimo enabled full duplex cellular networks"

Connected through hyperedge HE-2 (induced by source paper "modeling and performance of uplink cache enabled massive mimo heterogeneous networks"):
  with members:
    - "toward a realistic assessment of multiple antenna hcns residual additive transceiver hardware impairments and channel aging"
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "downlink mimo hcns with residual transceiver hardware impairments"
    - "cluster content caching an energy efficient approach to improve quality of service in cloud radio access networks"
    - "impact of user mobility on optimal linear receivers in cellular networks"
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design"
    - "analyzing uplink sinr and rate in massive mimo systems using stochastic geometry"

Connected through hyperedge HE-3 (induced by source paper "pilot reuse among d2d users in d2d underlaid massive mimo systems"):
  with members:
    - "energy efficient joint resource allocation and power control for d2d communications"
    - "graph coloring based pilot allocation to mitigate pilot contamination for multi cell massive mimo systems"
    - "energy efficient resource allocation for device to device underlay communication"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "the interplay between massive mimo and underlaid d2d networking"
    - "a survey on device to device communication in cellular networks"
    - "asymptotic coverage probability and rate in massive mimo networks"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"

Connected through hyperedge HE-4 (induced by source paper "analyzing uplink sinr and rate in massive mimo systems using stochastic geometry"):
  with members:
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "fractional pilot reuse in massive mimo systems"
    - "on stochastic geometry modeling of cellular uplink transmission with truncated channel inversion power control"
    - "aspects of favorable propagation in massive mimo"
    - "joint rate and sinr coverage analysis for decoupled uplink downlink biased cell associations in hetnets"
    - "analysis and optimization of inter tier interference coordination in downlink multi antenna hetnets with offloading"
    - "massive mimo for next generation wireless systems"
    - "coverage and rate analysis for millimeter wave cellular networks"

Connected through hyperedge HE-5 (induced by source paper "the interplay between massive mimo and underlaid d2d networking"):
  with members:
    - "spectrum sharing for device to device communication in cellular networks"
    - "massive mimo for next generation wireless systems"
    - "modeling analysis and optimization of multicast device to device transmissions"
    - "spectrum sharing scheme between cellular users and ad hoc device to device users"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "asymptotic coverage probability and rate in massive mimo networks"
    - "fundamental limits of distributed caching in d2d wireless networks"
    - "multi antenna communication in ad hoc networks achieving mimo gains with simo transmission"

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)