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: "effects of channel aging in massive mimo systems"
  Abstract: MIMO communication may provide high spectral efficiency through the deployment of a very large number of antenna elements at the base stations. The gains from massive MIMO communication come from the use of multi-user MIMO on the uplink and downlink, but with a large excess of antennas at the base station compared to the number of served users. Initial work on massive MIMO did not fully address several practical issues associated with its deployment. This paper considers the impact of channel aging on the performance of massive MIMO systems. The effects of channel variation are characterized as a function of different system parameters assuming a simple model for the channel time variations at the transmitter. Channel prediction is proposed to overcome channel aging effects. The analytical results on aging show how capacity is lost due to time variation in the channel. Numerical results in a multicell network show that massive MIMO works even with some channel variation and that channel prediction could partially overcome channel aging effects.

Connected through hyperedge HE-1 (induced by source paper "nuts and bolts of a realistic stochastic geometric analysis of mmwave hetnets hardware impairments and channel aging"):
  with members:
    - "toward a realistic assessment of multiple antenna hcns residual additive transceiver hardware impairments and channel aging"
    - "stochastic geometric coverage analysis in mmwave cellular networks with a realistic channel model"
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "rate splitting to mitigate residual transceiver hardware impairments in massive mimo systems"
    - "downlink mimo hcns with residual transceiver hardware impairments"
    - "hybrid architectures with few bit adc receivers achievable rates and energy rate tradeoffs"
    - "achievable rate and energy efficiency of hybrid and digital beamforming receivers with low resolution adc"
    - "coverage in heterogeneous downlink millimeter wave cellular networks"

Connected through hyperedge HE-2 (induced by source paper "addressing the curse of mobility in massive mimo with prony based angular delay domain channel predictions"):
  with members:
    - "massive mimo has unlimited capacity"
    - "robust pilot decontamination based on joint angle and power domain discrimination"
    - "massive mimo with multi cell mmse processing exploiting all pilots for interference suppression"
    - "sum rate and power scaling of massive mimo systems with channel aging"
    - "blind pilot decontamination"
    - "the degrees of freedom region of temporally correlated mimo networks with delayed csit"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-3 (induced by source paper "sampling for data freshness optimization non linear age functions"):
  with members:
    - "sampling for remote estimation through queues age of information and beyond"
    - "performance characterization using aoi in a single loop networked control system"
    - "age optimal updates of multiple information flows"
    - "the age of information in networks moments distributions and sampling"
    - "information aging through queues a mutual information perspective"
    - "a dynamic jamming game for real time status updates"
    - "joint status sampling and updating for minimizing age of information in the internet of things"
    - "optimizing information freshness in wireless networks under general interference constraints"

Connected through hyperedge HE-4 (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"
    - "multi user diversity vs accurate channel state information in mimo downlink channels"
    - "multi mode transmission for the mimo broadcast channel with imperfect channel state information"

Connected through hyperedge HE-5 (induced by source paper "achievable rates and training overheads for a measured los massive mimo channel"):
  with members:
    - "performance characterization of a real time massive mimo system with los mobile channels"
    - "the world s first real time testbed for massive mimo design implementation and validation"

Connected through hyperedge HE-6 (induced by source paper "heterogeneous doppler spread based csi estimation planning for tdd massive mimo"):
  with members:
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-7 (induced by source paper "otfs a new generation of modulation addressing the challenges of 5g"):
  with members:
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"

Connected through hyperedge HE-8 (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"
    - "performance of massive mimo uplink with zero forcing receivers under delayed channels"
    - "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"

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)