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: "a simple two stage equalizer with simplified orthogonal time frequency space modulation over rapidly time varying channels"
  Abstract: In this work, we derive a equivalent delay-Doppler channel matrix of the Orthogonal Time Frequency Space (OTFS) modulation that has not been studied in previous literature. It has the similar structure as the banded channel matrix of OFDM systems over rapidly time-varying channels. However, the band in the equivalent channel matrix will no longer spread with the increase of the Doppler spread once the length of maximum channel delay spread and the OTFS frame duration are deter- mined. Furthermore, the equivalent channel matrix can simplify the OTFS modulation in the transmitter side. Incorporating the equivalent channel matrix, we propose a simple two-stage equal- izer in 1 dimensional operations for OTFS modulation. First, the receive signal is equalized using the conventional OFDM single- tap equalizer in the frequency domain. The multipath effects can be removed. In the second stage, another low complexity delay- Doppler domain equalizer is employed to eliminate the effects of the residual interference caused by the Doppler spread with the equivalent channel matrix. The simulation results demonstrate that the proposed method is superior to the conventional single- tap equalizer and full minimum mean squared error (MMSE) equalizer of OFDM systems in terms of BER in high Doppler spread scenarios.

Connected through hyperedge HE-1 (induced by source paper "channel estimation for orthogonal time frequency space otfs massive mimo"):
  with members:
    - "mimo otfs in high doppler fading channels signal detection and channel estimation"
    - "orthogonal time frequency space modulation"
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "embedded pilot aided channel estimation for otfs in delay doppler channels"
    - "on otfs modulation for high doppler fading channels"
    - "interference cancellation and iterative detection for orthogonal time frequency space modulation"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
    - "millimeter wave vehicular communication to support massive automotive sensing"

Connected through hyperedge HE-2 (induced by source paper "multiple access in the delay doppler domain using otfs modulation"):
  with members:
    - "on the diversity of otfs modulation in doubly dispersive channels"
    - "mimo otfs in high doppler fading channels signal detection and channel estimation"
    - "orthogonal time frequency space modulation"
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "embedded pilot aided channel estimation for otfs in delay doppler channels"
    - "interference cancellation and iterative detection for orthogonal time frequency space modulation"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"

Connected through hyperedge HE-3 (induced by source paper "low complexity linear equalization for otfs systems with rectangular waveforms"):
  with members:
    - "otfs noma an efficient approach for exploiting heterogenous user mobility profiles"
    - "channel estimation for orthogonal time frequency space otfs massive mimo"
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "interference cancellation and iterative detection for orthogonal time frequency space modulation"
    - "analysis of discrete time mimo ofdm based orthogonal time frequency space modulation"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"

Connected through hyperedge HE-4 (induced by source paper "on the diversity of uncoded otfs modulation in doubly dispersive channels"):
  with members:
    - "mimo otfs in high doppler fading channels signal detection and channel estimation"
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "on otfs modulation for high doppler fading channels"
    - "interference cancellation and iterative detection for orthogonal time frequency space modulation"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
    - "otfs orthogonal time frequency space"

Connected through hyperedge HE-5 (induced by source paper "orthogonal time frequency space modulation"):
  with members:
    - "on otfs modulation for high doppler fading channels"
    - "low complexity equalization for orthogonal time and frequency signaling otfs"
    - "analysis of discrete time mimo ofdm based orthogonal time frequency space modulation"
    - "orthogonal precoding for ultra reliable wireless communication links"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
    - "otfs orthogonal time frequency space"
    - "comparison of the achievable rates in ofdm and single carrier modulation with i i d inputs"
    - "what will 5g be"

Connected through hyperedge HE-6 (induced by source paper "mimo otfs in high doppler fading channels signal detection and channel estimation"):
  with members:
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "on otfs modulation for high doppler fading channels"
    - "analysis of discrete time mimo ofdm based orthogonal time frequency space modulation"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
    - "otfs orthogonal time frequency space"

Connected through hyperedge HE-7 (induced by source paper "interference cancellation and iterative detection for orthogonal time frequency space modulation"):
  with members:
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "analysis of discrete time mimo ofdm based orthogonal time frequency space modulation"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
    - "low complexity detection in large dimension mimo isi channels using graphical models"
    - "noncoherent capacity of underspread fading channels"

Connected through hyperedge HE-8 (induced by source paper "on the diversity of otfs modulation in doubly dispersive channels"):
  with members:
    - "mimo otfs in high doppler fading channels signal detection and channel estimation"
    - "otfs a new generation of modulation addressing the challenges of 5g"
    - "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
    - "otfs orthogonal time frequency space"

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)