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: "impact of general channel aging conditions on the downlink performance of massive mimo"
  Abstract: Recent works have identified massive multiple-input multiple-output (MIMO) as a key technology for achieving substantial gains in spectral and energy efficiency. Additionally, the turn to low-cost transceivers, being prone to hardware impairments, is the most effective and attractive way for cost-efficient applications concerning massive MIMO systems. In this context, the impact of channel aging, which severely affects performance, is investigated herein by considering a generalized model. Specifically, we show that both Doppler shift due to the users' relative movement, as well as phase noise due to noisy local oscillators, contribute to channel aging. To this end, we first propose a joint model, encompassing both effects, to investigate the performance of a massive MIMO system based on the inevitable time-varying nature of realistic mobile communications. Then, we derive the deterministic equivalents for the signal-to-noise-and-interference ratios (SINRs) with maximum ratio transmission (MRT) and regularized zero-forcing (RZF) precoding. Our analysis not only demonstrates a performance comparison between MRT and RZF under these conditions but, most importantly, also reveals interesting properties regarding the effects of user mobility and phase noise. In particular, the large antenna limit behavior profoundly depends on both effects, but the burden due to user mobility is much more detrimental than phase noise even for moderate user velocities (    $\approx$   30 km/h), whereas the negative impact of phase noise is noteworthy at lower mobility conditions. Moreover, massive MIMO systems are favorable even in general channel aging conditions. Nevertheless, we demonstrate that the transmit power of each user to maintain a certain quality of service can be scaled down, at most, by    $\text{1}\sqrt{M}$   (    $M$   is the number of base station antennas), which indicates that the joint effects of phase noise and user mobility do not degrade the power scaling law but only the achievable sum-rate.

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"
    - "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"
    - "massive mimo ten myths and one critical question"

Connected through hyperedge HE-2 (induced by source paper "optimal reference signal design for phase noise compensation in multi carrier massive mimo systems"):
  with members:
    - "periodic analog channel estimation aided beamforming for massive mimo systems"
    - "continuous analog channel estimation aided beamforming for massive mimo systems"
    - "on the phase tracking reference signal pt rs design for 5g new radio nr"
    - "hybrid beamforming with selection for multiuser massive mimo systems"
    - "phase noise compensation for ofdm systems"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "dynamic subarrays for hybrid precoding in wideband mmwave mimo systems"
    - "hybrid beamforming for massive mimo a survey"

Connected through hyperedge HE-3 (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"
    - "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"
    - "an uplink interference analysis for massive mimo systems with mrc and zf receivers"
    - "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-4 (induced by source paper "toward a realistic assessment of multiple antenna hcns residual additive transceiver hardware impairments and channel aging"):
  with members:
    - "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"
    - "downlink performance of massive mimo under general channel aging conditions"

Connected through hyperedge HE-5 (induced by source paper "rate splitting to mitigate residual transceiver hardware impairments in massive mimo systems"):
  with members:
    - "energy efficiency in mimo underlay and overlay device to device communications and cognitive radio systems"
    - "sum rate maximization for linearly precoded downlink multiuser miso systems with partial csit a rate splitting approach"
    - "miso networks with imperfect csit a topological rate splitting approach"
    - "downlink mimo hcns with residual transceiver hardware impairments"
    - "robust transmission in downlink multiuser miso systems a rate splitting approach"
    - "a rate splitting strategy for max min fair multigroup multicasting"
    - "rate splitting for mimo wireless networks a promising phy layer strategy for lte evolution"
    - "a rate splitting strategy for massive mimo with imperfect csit"

Connected through hyperedge HE-6 (induced by source paper "performance scaling law for multi cell multi user massive mimo"):
  with members:
    - "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"
    - "sum rate and power scaling of massive mimo systems with channel aging"
    - "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-7 (induced by source paper "mitigation of phase noise in massive mimo systems a rate splitting approach"):
  with members:
    - "rate splitting to mitigate residual transceiver hardware impairments in massive mimo systems"
    - "rate splitting for mimo wireless networks a promising phy layer strategy for lte evolution"
    - "a rate splitting strategy for massive mimo with imperfect csit"
    - "rate analysis of two receiver miso broadcast channel with finite rate feedback a rate splitting approach"
    - "uplink performance of time reversal mrc in massive mimo systems subject to phase noise"
    - "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design"
    - "massive mimo multicasting in noncooperative cellular networks"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-8 (induced by source paper "performance characterization of a real time massive mimo system with los mobile channels"):
  with members:
    - "performance of massive mimo uplink with zero forcing receivers under delayed channels"
    - "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"

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)