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 "carrier phase estimation in dispersion unmanaged optical transmission systems"):
  Abstract: The study on carrier phase estimation (CPE) approaches, involving a one-tap normalized least-mean-square (NLMS) algorithm, a block-wise average algorithm, and a Viterbi-Viterbi algorithm has been carried out in the long-haul high-capacity dispersion-unmanaged coherent optical systems. The close-form expressions and analytical predictions for bit-error-rate behaviors in these CPE methods have been analyzed by considering both the laser phase noise and the equalization enhanced phase noise. It is found that the Viterbi-Viterbi algorithm outperforms the one-tap NLMS and the block-wise average algorithms for a small phase noise variance (or effective phase noise variance), while the three CPE methods converge to a similar performance for a large phase noise variance (or effective phase noise variance). In addition, the differences between the three CPE approaches become smaller for higher-level modulation formats.

Includes members:
  Member "achievable information rates estimates in optically amplified transmission systems using nonlinearity compensation and probabilistic shaping":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "digital signal processing for optical communications and networks i linear compensation")
  Member "analytical investigations on carrier phase recovery in dispersion unmanaged n psk coherent optical communication systems":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "digital signal processing for optical communications and networks i linear compensation")
  Member "phase noise influence in long range coherent optical ofdm systems with delay detection ifft multiplexing and fft demodulation":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "digital signal processing for optical communications and networks i linear compensation")
  Member "phase noise influence in coherent optical ofdm systems with rf pilot tone digital ifft multiplexing and fft demodulation":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "digital signal processing for optical communications and networks i linear compensation")
  Member "analytical estimation in differential optical transmission systems influenced by equalization enhanced phase noise":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "digital signal processing for optical communications and networks i linear compensation")
  Member "digital adaptive carrier phase estimation in multi level phase shift keying coherent optical communication systems":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "digital signal processing for optical communications and networks i linear compensation")

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)