human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "a tight lower bound to the outage probability of discrete input block fading channels"
  Abstract: In this correspondence, a tight lower bound to the outage probability of discrete-input Nakagami-m block-fading channels is proposed. The approach permits an efficient method for numerical evaluation of the bound, providing an additional tool for system design. The optimal rate-diversity tradeoff for the Nakagami-m block-fading channel is also derived and a tight upper bound is obtained for the optimal coding gain constant.

Connected through hyperedge HE-1 (induced by source paper "time varying space only codes for coded mimo"):
  with members:
    - "sphere decoding complexity exponent for decoding full rate codes over the quasi static mimo channel"
    - "precoding for outage probability minimization on block fading channels"
    - "space time coding techniques with bit interleaved coded modulations for mimo block fading channels"
    - "approximately universal codes over slow fading channels"

Connected through hyperedge HE-2 (induced by source paper "macro and micro diversity behaviors of practical dynamic decode and forward relaying schemes"):
  with members:
    - "cooperative hybrid arq protocols unified frameworks for protocol analysis"
    - "approximately universal space time codes for the parallel multi block and cooperative dynamic decode and forward channels"
    - "coding for the non orthogonal amplify and forward cooperative channel"

Connected through hyperedge HE-3 (induced by source paper "multi user mimo scheduling in the fourth generation cellular uplink"):
  with members:
    - "multi user scheduling in the 3gpp lte cellular uplink"
    - "sub modularity and antenna selection in mimo systems"
    - "efficient submodular function maximization under linear packing constraints"
    - "on k column sparse packing programs"
    - "limited feedback based block diagonalization for the mimo broadcast channel"
    - "message passing resource allocation for the uplink of multicarrier systems"
    - "joint beamforming for multiaccess mimo systems with finite rate feedback"
    - "multiuser mimo achievable rates with downlink training and channel state feedback"

Connected through hyperedge HE-4 (induced by source paper "coded modulation with mismatched csit over block fading channels"):
  with members:
    - "two models for noisy feedback in mimo channels"

Question: Please tell me which class the center node 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)