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: "optimal coordinated beamforming in the multicell downlink with transceiver impairments"
  Abstract: Physical wireless transceivers suffer from a variety of impairments that distort the transmitted and received signals. Their degrading impact is particularly evident in modern systems with multiuser transmission, high transmit power, and low-cost devices, but their existence is routinely ignored in the optimization literature for multicell transmission. This paper provides a detailed analysis of coordinated beamforming in the multicell downlink. We solve two optimization problems under a transceiver impairment model and derive the structure of the optimal solutions. We show numerically that these solutions greatly reduce the impact of impairments, compared with beamforming developed for ideal transceivers. Although the so-called multiplexing gain is zero under transceiver impairments, we show that the gain of multiplexing can be large at practical SNRs.

Connected through hyperedge HE-1 (induced by source paper "ergodic capacity evaluation of wireless thz fiber extenders"):
  with members:
    - "wireless terahertz system architectures for networks beyond 5g"
    - "low cost cognitive radios against spectrum scarcity"
    - "terahertz technologies to deliver optical network quality of experience in wireless systems beyond 5g"
    - "i q imbalance self interference coordination"
    - "millimeter wave cellular networks a mac layer perspective"
    - "massive mimo systems with hardware constrained base stations"
    - "a new look at dual hop relaying performance limits with hardware impairments"
    - "mimo transmission with residual transmit rf impairments"

Connected through hyperedge HE-2 (induced by source paper "on the energy efficiency of mimo hybrid beamforming for millimeter wave systems with nonlinear power amplifiers"):
  with members:
    - "spatial characteristics of distortion radiated from antenna arrays with transceiver nonlinearities"
    - "codebook based hybrid precoding for millimeter wave multiuser systems"
    - "common codebook millimeter wave beam design designing beams for both sounding and communication with uniform planar arrays"
    - "spectrum sharing in mmwave cellular networks via cell association coordination and beamforming"
    - "waveforms for the massive mimo downlink amplifier efficiency distortion and performance"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"

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"
    - "sum rate and power scaling of massive mimo systems with channel aging"

Connected through hyperedge HE-4 (induced by source paper "power efficient and secure wpcns with hardware impairments and non linear eh circuit"):
  with members:
    - "spectral efficiency of multipair massive mimo two way relaying with hardware impairments"
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "max min fair beamforming for swipt systems with non linear eh model"
    - "power allocation for secure swipt systems with wireless powered cooperative jamming"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "analysis and design of secure massive mimo systems in the presence of hardware impairments"
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "wireless powered communication networks an overview"

Connected through hyperedge HE-5 (induced by source paper "rate splitting to mitigate residual transceiver hardware impairments in massive mimo systems"):
  with members:
    - "impact of general channel aging conditions on the downlink performance of massive mimo"
    - "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"

Connected through hyperedge HE-6 (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"
    - "sum rate and power scaling of massive mimo systems with channel aging"
    - "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"

Connected through hyperedge HE-7 (induced by source paper "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"):
  with members:
    - "uplink performance of time reversal mrc in massive mimo systems subject to phase noise"
    - "robust estimates of covariance matrices in the large dimensional regime"
    - "low complexity polynomial channel estimation in large scale mimo with arbitrary statistics"
    - "blind pilot decontamination"
    - "massive mimo and small cells improving energy efficiency by optimal soft cell coordination"
    - "capacity limits and multiplexing gains of mimo channels with transceiver impairments"
    - "hardware impairments in large scale miso systems energy efficiency estimation and capacity limits"
    - "linear precoding based on polynomial expansion reducing complexity in massive mimo"

Connected through hyperedge HE-8 (induced by source paper "interference alignment ia and coordinated multi point comp overheads and rf impairments testbed results"):
  with members:
    - "interference alignment ia and coordinated multi point comp with ieee802 11ac feedback compression testbed results"
    - "an experimental investigation of simo mimo interference alignment ia and coordinated multi point comp"
    - "on feasibility of interference alignment in mimo interference networks"
    - "on feasibility of interference alignment in mimo interference networks"
    - "approaching the capacity of wireless networks through distributed interference alignment"

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)