human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "indoor location estimation with optical based ofdm communications"):
  Abstract: Visible Light Communication (VLC) using light emitting diodes (LEDs) has been gaining increasing attention in recent years as it is appealing for a wide range of applications such as indoor positioning. Orthogonal frequency division multiplexing (OFDM) has been applied to indoor wireless optical communications in order to mitigate the effect of multipath distortion of the optical channel as well as increasing data rate. In this paper, a novel OFDM VLC system is proposed which can be utilized for both communications and indoor positioning. A positioning algorithm based on power attenuation is used to estimate the receiver coordinates. We further calculate the positioning errors in all the locations of a room and compare them with those using single carrier modulation scheme, i.e., on-off keying (OOK) modulation. We demonstrate that OFDM positioning system outperforms its conventional counterpart. Finally, we investigate the impact of different system parameters on the positioning accuracy of the proposed OFDM VLC system.

Includes members:
  Member "impact of multipath reflections on the performance of indoor visible light positioning systems":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "localisation communication and networking with vlc challenges and opportunities")
  Member "indoor positioning in high speed ofdm visible light communications":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "impact of multipath reflections on the performance of indoor visible light positioning systems")
  Member "robust timing synchronization for ac ofdm based optical wireless communications":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "impact of multipath reflections on the performance of indoor visible light positioning systems")
  Member "on the performance of single and multi carrie modulation schemes for indoor visible light communication systems":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "impact of multipath reflections on the performance of indoor visible light positioning systems")
  Member "flip ofdm for unipolar communication systems":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "a comparative study of unipolar ofdm schemes in gaussian optical intensity channel")

Question: Please tell me which class the source paper 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)