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: "waveforms for the massive mimo downlink amplifier efficiency distortion and performance"
  Abstract: In massive multiple-input multiple-output (MIMO), most precoders result in downlink signals that suffer from high peak-to-average ratio (PAR), independently of modulation order and whether single-carrier or orthogonal frequency-division multiplexing (OFDM) transmission is used. The high PAR lowers the power efficiency of the base-station amplifiers. To increase the power efficiency, low-PAR precoders have been proposed. In this paper, we compare different transmission methods for massive MIMO in terms of the power consumed by the amplifiers. It is found that: 1) OFDM and single-carrier transmission have the same performance over a hardened massive MIMO channel and 2) when the higher amplifier power efficiency of low-PAR precoding is taken into account, conventional and low-PAR precoders lead to approximately the same power consumption. Since downlink signals with low PAR allow for simpler and cheaper hardware, than signals with high PAR, therefore, the results suggest that low-PAR precoding with either single-carrier or OFDM transmission should be used in a massive MIMO base station.

Connected through hyperedge HE-1 (induced by source paper "the effect of spatial correlation on the performance of uplink and downlink single carrier massive mimo systems"):
  with members:
    - "average sep optimal precoding for correlated massive mimo with zf detection an asymptotic analysis"
    - "uplink massive mimo for channels with spatial correlation"
    - "mimo channel modeling and capacity analysis for 5g millimeter wave wireless systems"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "massive mimo for next generation wireless systems"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "diversity of mimo linear precoding"

Connected through hyperedge HE-2 (induced by source paper "quantized constant envelope precoding with psk and qam signaling"):
  with members:
    - "1 bit massive mu mimo precoding in vlsi"
    - "branch and bound precoding for multiuser mimo systems with 1 bit quantization"
    - "quantized precoding for multi antenna downlink channels with magiq"
    - "nonlinear precoding for phase quantized constant envelope massive mu mimo ofdm"
    - "linear precoding with low resolution dacs for massive mu mimo ofdm downlink"
    - "psk precoding in multi user miso systems"
    - "massive mimo downlink 1 bit precoding with linear programming for psk signaling"
    - "an efficient manifold algorithm for constructive interference based constant envelope precoding"

Connected through hyperedge HE-3 (induced by source paper "spectral efficiency of mixed adc massive mimo"):
  with members:
    - "a comparison of hybrid beamforming and digital beamforming with low resolution adcs for multiple users and imperfect csi"
    - "spatial characteristics of distortion radiated from antenna arrays with transceiver nonlinearities"
    - "throughput analysis of massive mimo uplink with low resolution adcs"
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "impact of spatial filtering on distortion from low noise amplifiers in massive mimo base stations"
    - "performance analysis of mixed adc massive mimo systems over rician fading channels"
    - "uplink performance of wideband massive mimo with one bit adcs"
    - "mixed adc massive mimo"

Connected through hyperedge HE-4 (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"
    - "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"
    - "training sequence design for feedback assisted hybrid beamforming in massive mimo systems"

Connected through hyperedge HE-5 (induced by source paper "uplink performance of wideband massive mimo with one bit adcs"):
  with members:
    - "throughput analysis of massive mimo uplink with low resolution adcs"
    - "massive mimo with low resolution adcs"
    - "mixed adc massive mimo"
    - "mixed adc massive mimo uplink in frequency selective channels"
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "uplink achievable rate for massive mimo systems with low resolution adc"
    - "capacity analysis of one bit quantized mimo systems with transmitter channel state information"
    - "near maximum likelihood detector and channel estimator for uplink multiuser massive mimo systems with one bit adcs"

Connected through hyperedge HE-6 (induced by source paper "on out of band emissions of quantized precoding in massive mu mimo ofdm"):
  with members:
    - "1 bit massive mu mimo precoding in vlsi"
    - "linear precoding with low resolution dacs for massive mu mimo ofdm downlink"
    - "massive mu mimo ofdm downlink with one bit dacs and linear precoding"
    - "analysis of one bit quantized precoding for the multiuser massive mimo downlink"
    - "downlink achievable rate analysis in massive mimo systems with one bit dacs"
    - "minimum ber precoding in 1 bit massive mimo systems"
    - "out of band radiation measure for mimo arrays with beamformed transmission"
    - "quantized precoding for massive mu mimo"

Connected through hyperedge HE-7 (induced by source paper "performance of the wideband massive uplink mimo with one bit adcs"):
  with members:
    - "massive mimo with low resolution adcs"
    - "mixed adc massive mimo"
    - "mixed adc massive mimo uplink in frequency selective channels"
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "uplink achievable rate for massive mimo systems with low resolution adc"
    - "capacity analysis of one bit quantized mimo systems with transmitter channel state information"
    - "near maximum likelihood detector and channel estimator for uplink multiuser massive mimo systems with one bit adcs"
    - "quantized massive mu mimo ofdm uplink"

Connected through hyperedge HE-8 (induced by source paper "out of band radiation measure for mimo arrays with beamformed transmission"):
  with members:
    - "analysis of massive mimo with hardware impairments and different channel models"
    - "optimal multiuser transmit beamforming a difficult problem with a simple solution structure"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"
    - "massive mimo for next generation wireless systems"
    - "optimal linear precoding in multi user mimo systems a large system analysis"
    - "on the impact of hardware impairments on massive mimo"

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)