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 "amplify and forward two way relaying system over free space optics channels"):
  Abstract: In this paper, we analyze the performance of a two- way subcarrier intensity-modulated (SIM) amplify-and-forward (AF) relaying system over free-space optics (FSO) communication channels. The analysis takes into consideration attenuations due to atmospheric turbulence, geometric spread and pointing errors at the same time. We derive, in generalized infinite power series expressions, the tight upper and lower bounds of the overall outage probability and average probability of errors of the system. The study finds that this two-way subcarrier intensity- modulated AF relaying system using a binary phase shift keying (BPSK) modulation could be used for practical applications in case of a weak turbulence regime in which the required SNR is about 30 dB to obtain the average bit error probability of 10-6. It is also noted that the pointing errors clearly degrade the performance of the two-way subcarrier intensity-modulated AF relaying system.

Includes members:
  Member "performance analysis of massive mimo for cell boundary users":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "a retrodirective wireless power transfer scheme for ambient backscatter systems")
  Member "prototyping real time full duplex radios":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "ultrareliable and low latency communication techniques for tactile internet services")
  Member "compressed channel feedback for correlated massive mimo systems":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "high dimensional stochastic gradient quantization for communication efficient edge learning")
  Member "impact of pointing errors on the performance of mixed rf fso dual hop transmission systems":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "fundamental limits of spectrum sharing for noma based cooperative relaying under a peak interference constraint")

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)