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: "performance of massive mimo uplink with zero forcing receivers under delayed channels"
  Abstract: In this paper, we analyze the performance of the uplink communication of massive multicell multiple-input multiple-output (MIMO) systems under the effects of pilot contamination and delayed channels because of terminal mobility. The base stations (BSs) estimate the channels through the uplink training and then use zero-forcing (ZF) processing to decode the transmit signals from the users. The probability density function (pdf) of the signal-to-interference-plus-noise ratio (SINR) is derived for any finite number of antennas. From this pdf, we derive an achievable ergodic rate with a finite number of BS antennas in closed form. Insights into the impact of the Doppler shift (due to terminal mobility) at the low signal-to-noise ratio (SNR) regimes are exposed. In addition, the effects on the outage probability are investigated. Furthermore, the power scaling law and the asymptotic performance result by infinitely increasing the numbers of antennas and terminals (while their ratio is fixed) are provided. The numerical results demonstrate the performance loss for various Doppler shifts. Among the interesting observations revealed is that massive MIMO is favorable even under channel aging conditions.

Connected through hyperedge HE-1 (induced by source paper "closed form performance analysis of linear mimo receivers in general fading scenarios"):
  with members:
    - "on the outage capacity of orthogonal space time block codes over multi cluster scattering mimo channels"
    - "schur complement based analysis of mimo zero forcing for rician fading"
    - "exact mimo zero forcing detection analysis for transmit correlated rician fading"
    - "asymptotic performance of linear receivers in mimo fading channels"

Connected through hyperedge HE-2 (induced by source paper "toward a realistic assessment of multiple antenna hcns residual additive transceiver hardware impairments and channel aging"):
  with members:
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "mitigation of phase noise in massive mimo systems a rate splitting approach"
    - "rate splitting to mitigate residual transceiver hardware impairments in massive mimo systems"
    - "analysis and design of secure massive mimo systems in the presence of hardware impairments"
    - "downlink mimo hcns with residual transceiver hardware impairments"
    - "sum rate and power scaling of massive mimo systems with channel aging"
    - "downlink performance of massive mimo under general channel aging conditions"

Connected through hyperedge HE-3 (induced by source paper "performance characterization of a real time massive mimo system with los mobile channels"):
  with members:
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "the world s first real time testbed for massive mimo design implementation and validation"
    - "massive mimo ten myths and one critical question"
    - "reciprocity calibration for massive mimo proposal modeling and validation"
    - "massive mimo 10 myths and one grand question"
    - "massive mimo performance evaluation based on measured propagation data"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-4 (induced by source paper "temporal analysis of measured los massive mimo channels with mobility"):
  with members:
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "the world s first real time testbed for massive mimo design implementation and validation"
    - "reciprocity calibration for massive mimo proposal modeling and validation"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"
    - "massive mimo for next generation wireless systems"

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)