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: "diversity of mimo multihop relay channels"
  Abstract: We consider slow fading relay channels with a single multi-antenna source-destination terminal pair. The source signal arrives at the destination via N hops through N − 1 layers of relays. We analyze the diversity of such channels with fixed network size at high SNR. In the clustered case where the relays within the same layer can have full cooperation, the cooperative decode-and-forward (DF) scheme is shown to be optimal in terms of the diversity-multiplexing tradeoff (DMT). The upper bound on the DMT, the cut-set bound, is attained. In the non-clustered case, we show that the naive amplify-andforward (AF) scheme has the maximum multiplexing gain of the channel but is suboptimal in diversity, as compared to the cut-set bound. To improve the diversity, space-time relay processing is introduced through the parallel partition of the multihop channel. The idea is to let the source signal go through K different “AF paths” in the multihop channel. This parallel AF scheme creates a parallel channel in the time domain and has the maximum diversity if the partition is properly designed. Since this scheme does not achieve the maximum multiplexing gain in general, we propose a flip-and-forward (FF) scheme that is built from the parallel AF scheme. It is shown that the FF scheme achieves both the maximum diversity and multiplexing gains in a distributed multihop channel of arbitrary size. In order to realize the DMT promised by the relaying strategies, approximately universal coding schemes are also proposed.

Connected through hyperedge HE-1 (induced by source paper "cooperation and underlay mode selection in cognitive radio network"):
  with members:
    - "on the stable throughput of cooperative cognitive radio networks with finite relaying buffer"
    - "maximum throughput of a cooperative energy harvesting cognitive radio user"
    - "protocol design and stability analysis of cooperative cognitive radio users"

Connected through hyperedge HE-2 (induced by source paper "capacity and power scaling laws for finite antenna mimo amplify and forward relay networks"):
  with members:
    - "asymptotic performance analysis of a k hop amplify and forward relay mimo channel"
    - "capacity approximations for gaussian relay networks"
    - "asymptotic capacity and optimal precoding in mimo multi hop relay networks"
    - "ergodic capacity analysis of amplify and forward mimo dual hop systems"
    - "on information rates of the fading wyner cellular model via the thouless formula for the strip"
    - "crystallization in large wireless networks"
    - "hierarchical cooperation achieves optimal capacity scaling in ad hoc networks"

Connected through hyperedge HE-3 (induced by source paper "a tutorial on the optimization of amplify and forward mimo relay systems"):
  with members:
    - "power allocation in two hop amplify and forward mimo relay systems with qos requirements"
    - "asymptotic capacity and optimal precoding in mimo multi hop relay networks"
    - "transceiver design for dual hop nonregenerative mimo ofdm relay systems under channel uncertainties"
    - "achievable rate regions for bi directional relaying"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"

Connected through hyperedge HE-4 (induced by source paper "performance analysis of optimal single stream beamforming in mimo dual hop af systems"):
  with members:
    - "ergodic capacity analysis of amplify and forward mimo dual hop systems"
    - "crystallization in large wireless networks"
    - "large n analysis of amplify and forward mimo relay channels with correlated rayleigh fading"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"

Connected through hyperedge HE-5 (induced by source paper "asymptotic capacity and optimal precoding in mimo multi hop relay networks"):
  with members:
    - "asymptotic capacity of large fading relay networks with random node failures"
    - "on the non coherent wideband multipath fading relay channel"
    - "asymptotic capacity and optimal precoding strategy of multi level precode forward in correlated channels"
    - "crystallization in large wireless networks"
    - "capacity scaling for mimo two way relaying"
    - "hierarchical cooperation achieves optimal capacity scaling in ad hoc networks"

Connected through hyperedge HE-6 (induced by source paper "ergodic capacity analysis of amplify and forward mimo dual hop systems"):
  with members:
    - "crystallization in large wireless networks"
    - "on the capacity of doubly correlated mimo channels"
    - "large n analysis of amplify and forward mimo relay channels with correlated rayleigh fading"

Connected through hyperedge HE-7 (induced by source paper "end to end joint antenna selection strategy and distributed compress and forward strategy for relay channels"):
  with members:
    - "to code or not to code in multi hop relay channels"
    - "dmt of multi hop cooperative networks part ii half duplex networks with full duplex performance"
    - "nonregenerative mimo relaying with optimal transmit antenna selection"
    - "relay subset selection in wireless networks using partial decode and forward transmission"
    - "a simple cooperative diversity method based on network path selection"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"

Connected through hyperedge HE-8 (induced by source paper "multi hop cooperative wireless networks diversity multiplexing tradeoff and optimal code design"):
  with members:
    - "diversity and degrees of freedom of cooperative wireless networks"
    - "a deterministic approach to wireless relay networks"
    - "optimum diversity multiplexing tradeoff in the multiple relays network"
    - "diversity multiplexing tradeoff of asynchronous cooperative diversity in wireless networks"
    - "towards the optimal amplify and forward cooperative diversity scheme"
    - "d mg tradeoff and optimal codes for a class of af and df cooperative communication protocols"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"
    - "approximately universal codes over slow fading 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)