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: "sum rate and power scaling of massive mimo systems with channel aging"
  Abstract: This paper investigates the achievable sum-rate of massive multiple-input multiple-output (MIMO) systems in the presence of channel aging. For the uplink, by assuming that the base station (BS) deploys maximum ratio combining (MRC) or zero-forcing (ZF) receivers, we present tight closed-form lower bounds on the achievable sum-rate for both receivers with aged channel state information (CSI). In addition, the benefit of implementing channel prediction methods on the sum-rate is examined, and closed-form sum-rate lower bounds are derived. Moreover, the impact of channel aging and channel prediction on the power scaling law is characterized. Extension to the downlink scenario and multicell scenario is also considered. It is found that, for a system with/without channel prediction, the transmit power of each user can be scaled down at most by   $1/\sqrt{M}$   (where   $M$   is the number of BS antennas), which indicates that aged CSI does not degrade the power scaling law, and channel prediction does not enhance the power scaling law; instead, these phenomena affect the achievable sum-rate by degrading or enhancing the effective signal to interference and noise ratio, respectively.

Connected through hyperedge HE-1 (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"
    - "blind pilot decontamination"
    - "the degrees of freedom region of temporally correlated mimo networks with delayed csit"
    - "effects of channel aging in massive mimo systems"
    - "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-2 (induced by source paper "multipair massive mimo relaying systems with one bit adc s and dac s"):
  with members:
    - "throughput analysis of massive mimo uplink with low resolution adcs"
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "achievable uplink rates for massive mimo with coarse quantization"
    - "bayes optimal joint channel and data estimation for massive mimo with low precision adcs"
    - "downlink achievable rate analysis in massive mimo systems with one bit dacs"
    - "adc bit allocation under a power constraint for mmwave massive mimo communication receivers"
    - "mixed adc massive mimo uplink in frequency selective channels"
    - "spectral efficiency of mixed adc receivers for massive mimo systems"

Connected through hyperedge HE-3 (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"
    - "downlink performance of massive mimo under general channel aging conditions"

Connected through hyperedge HE-4 (induced by source paper "impact of general channel aging conditions on the downlink performance of massive mimo"):
  with members:
    - "massive mimo ten myths and one critical question"
    - "massive mimo 10 myths and one grand question"
    - "impact of user mobility on optimal linear receivers in cellular networks"
    - "downlink performance of massive mimo under general channel aging conditions"
    - "uplink performance of time reversal mrc in massive mimo systems subject to phase noise"
    - "uplink performance of conventional and massive mimo cellular systems with delayed csit"
    - "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design"
    - "on the impact of oscillator phase noise on the uplink performance in a massive mimo ofdm system"

Connected through hyperedge HE-5 (induced by source paper "performance scaling law for multi cell multi user massive mimo"):
  with members:
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "pilot length optimization for spatially correlated multi user mimo channel estimation"
    - "performance analysis and scaling law of mrc mrt relaying with csi error in massive mimo systems"
    - "massive mimo ten myths and one critical question"
    - "on the convergence of massive mimo systems"
    - "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"
    - "blind pilot decontamination"

Connected through hyperedge HE-6 (induced by source paper "performance of massive mimo uplink with zero forcing receivers under delayed channels"):
  with members:
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "uplink performance of conventional and massive mimo cellular systems with delayed csit"
    - "massive mimo for next generation wireless systems"
    - "effects of channel aging in massive mimo systems"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "pilot contamination and precoding in multi cell tdd systems"
    - "mimo diversity in the presence of double scattering"

Connected through hyperedge HE-7 (induced by source paper "enhancing massive mimo a new approach for uplink training based on heterogeneous coherence time"):
  with members:
    - "effects of channel aging in massive mimo 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)