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 "a novel scheme for downlink opportunistic interference alignment"):
  Abstract: In this paper we propose a downlink codebook-based opportunistic interference alignment (OIA) in a three-cell MIMO system. A codebook composed of multiple transmit vector sets is utilized to improve the multiuser selection diversity. The sum rate increases as the size of the codebook grows. In addition, during the user selection, effective channel gain and alignment metric are combined to generate a novel criterion, which improves the system performance, especially at low SNR. Furthermore, a threshold-based feedback approach is introduced to reduce the feedback load in the proposed scheme. Both the analytical results and simulations show that the proposed scheme provides significant improvement in terms of sum rates with no feedback load growth and slight increase of complexity.

Includes members:
  Member "codebook based opportunistic interference alignment":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "opportunistic downlink interference alignment for multi cell mimo networks")
  Member "limited feedback based interference alignment for interfering multi access channels":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "iterative distributed minimum total mse approach for secure communications in mimo interference channels")
  Member "performance analysis and optimization for interference alignment over mimo interference channels with limited feedback":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "provisioning energy efficiency and qos for multi carrier comp with limited feedback")
  Member "on the achievable dof and user scaling law of opportunistic interference alignment in 3 transmitter mimo interference channels":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "opportunistic downlink interference alignment for multi cell mimo networks")
  Member "cooperative algorithms for mimo interference channels":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "the capacity and optimal signaling for gaussian mimo channels under interference constraints full version")

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)