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: "low complexity modem structure for ofdm based orthogonal time frequency space modulation"
  Abstract: Orthogonal time frequency space (OTFS) modulation is a two-dimensional signaling technique that has recently emerged in the literature to tackle the time-varying (TV) wireless channels. OTFS deploys the Doppler-delay plane to multiplex the transmit data where the time variations of the TV channel are integrated over time and hence the equivalent channel relating the input and output of the system boils down to a time-invariant one. This signaling technique can be implemented on the top of a given multicarrier waveform with the addition of precoding and post-processing units to the modulator and demodulator. In this paper, we present discrete-time formulation of an OFDM-based OTFS system. We argue against deployment of window functions at the OTFS transmitter in realistic scenarios and thus limit any sort of windowing to the receiver side. We study the channel impact in discrete-time providing deeper insights into OTFS systems. Moreover, our derivations lead to simplified modulator and demodulator structures that are far simpler than those in the literature.

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"
    - "a simple two stage equalizer with simplified orthogonal time frequency space modulation over rapidly time varying channels"
    - "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"
    - "a simple two stage equalizer with simplified orthogonal time frequency space modulation over rapidly time varying channels"

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"
    - "a simple two stage equalizer with simplified orthogonal time frequency space modulation over rapidly time varying channels"
    - "analysis of discrete time mimo 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"
    - "a simple two stage equalizer with simplified orthogonal time frequency space modulation over rapidly time varying channels"
    - "otfs orthogonal time frequency space"

Connected through hyperedge HE-5 (induced by source paper "orthogonal time frequency space otfs modulation based radar system"):
  with members:
    - "orthogonal time frequency space modulation"
    - "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"

Connected through hyperedge HE-6 (induced by source paper "circularly pulse shaped orthogonal time frequency space modulation"):
  with members:
    - "on the diversity of uncoded otfs modulation in doubly dispersive channels"
    - "interference cancellation and iterative detection for orthogonal time frequency space modulation"
    - "matrix characterization for gfdm low complexity mmse receivers and optimal filters"

Connected through hyperedge HE-7 (induced by source paper "low complexity lmmse receiver for otfs"):
  with members:
    - "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"

Connected through hyperedge HE-8 (induced by source paper "orthogonal time frequency space modulation"):
  with members:
    - "on otfs modulation for high doppler fading channels"
    - "a simple two stage equalizer with simplified orthogonal time frequency space modulation over rapidly time varying 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"
    - "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"

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)