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 "opportunistic spatial orthogonalization and its application in fading cognitive radio networks"):
  Abstract: Opportunistic Spatial Orthogonalization (OSO) is a cognitive radio scheme that allows the existence of secondary users and hence increases the system throughput, even if the primary user occupies all the frequency bands all the time. Notably, this throughput advantage is obtained without sacrificing the performance of the primary user, if the interference margin is carefully chosen. The key idea is to exploit the spatial dimensions to orthogonalize users and hence minimize interference. However, unlike the time and frequency dimensions, there is no universal basis for the set of all multi-dimensional spatial channels, which motivated the development of OSO. On one hand, OSO can be viewed as a multi-user diversity scheme that exploits the channel randomness and independence. On the other hand, OSO can be interpreted as an opportunistic interference alignment scheme, where the interference from multiple secondary users is opportunistically aligned at the direction that is orthogonal to the primary user's signal space. In the case of multiple-input multiple-output (MIMO) channels, the OSO scheme can be interpreted as "riding the peaks" over the eigen-channels, and ill-conditioned MIMO channel, which is traditionally viewed as detrimental, is shown to be beneficial with respect to the sum throughput. Throughput advantages are thoroughly studied, both analytically and numerically.

Includes members:
  Member "opportunistic interference alignment in mimo interference channels":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "cache enabled wireless networks with opportunistic interference alignment")
  Member "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "optimal precoder designs for sum utility maximization in swipt enabled multi user mimo cognitive radio networks")
  Member "approaching the capacity of wireless networks through distributed interference alignment":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "fundamental limits of dynamic interference management with flexible message assignments")
  Member "exploiting new forms of multiuser diversity for spectrum sharing in cognitive radio networks":
    also connected through other hyperedges:
      (none)
  Member "gaussian interference channel capacity to within one bit":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "fundamental limits of wireless caching under mixed cacheable and uncacheable traffic")
  Member "interference alignment and the degrees of freedom for the k user interference channel":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "on off switched interference alignment for diversity multiplexing tradeoff improvement in the 2 user x network with two antennas")

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)