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: "performance bounds for bi directional coded cooperation protocols"
  Abstract: In coded bi-directional cooperation, two nodes wish to exchange messages over a shared half-duplex channel with the help of a relay. In this paper, we derive performance bounds for this problem for each of three protocols. #R##N#The first protocol is a two phase protocol were both users simultaneously transmit during the first phase and the relay alone transmits during the second. In this protocol, our bounds are tight and a multiple-access channel transmission from the two users to the relay followed by a coded broadcast-type transmission from the relay to the users achieves all points in the two-phase capacity region. #R##N#The second protocol considers sequential transmissions from the two users followed by a transmission from the relay while the third protocol is a hybrid of the first two protocols and has four phases. In the latter two protocols the inner and outer bounds are not identical, and differ in a manner similar to the inner and outer bounds of Cover's relay channel. Numerical evaluation shows that at least in some cases of interest our bounds do not differ significantly. #R##N#Finally, in the Gaussian case with path loss, we derive achievable rates and compare the relative merits of each protocol in various regimes. This case is of interest in cellular systems. Surprisingly, we find that in some cases, the achievable rate region of the four phase protocol sometimes contains points that are outside the outer bounds of the other protocols.

Connected through hyperedge HE-1 (induced by source paper "integer forcing and forward transceiver design for mimo multipair two way relaying"):
  with members:
    - "compute and forward two way relaying"
    - "successive integer forcing and its sum rate optimality"
    - "reliable physical layer network coding"
    - "integer forcing linear receivers"
    - "compute and forward harnessing interference through structured codes"
    - "physical network coding in two way wireless relay channels"

Connected through hyperedge HE-2 (induced by source paper "compute and forward two way relaying"):
  with members:
    - "compute and forward on a multiaccess relay channel coding and symmetric rate optimization"
    - "compute and forward strategies for cooperative distributed antenna systems"
    - "reliable physical layer network coding"
    - "integer forcing linear receivers"
    - "compute and forward harnessing interference through structured codes"
    - "physical network coding in two way wireless relay channels"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-3 (induced by source paper "achievable rate regions for two way relay channel using nested lattice coding"):
  with members:
    - "lattice coding for the two way two relay channel"
    - "a lattice compress and forward scheme"
    - "lattice codes for the gaussian relay channel decode and forward and compress and forward"
    - "wyner ziv coding over broadcast channels digital schemes"
    - "compute and forward harnessing interference through structured codes"
    - "physical layer network coding"

Connected through hyperedge HE-4 (induced by source paper "compute and forward on a multi user multi relay channel"):
  with members:
    - "throughput optimized multi source cooperative networks with compute and forward"
    - "compute and forward on a multiaccess relay channel coding and symmetric rate optimization"
    - "compute and forward harnessing interference through structured codes"

Connected through hyperedge HE-5 (induced by source paper "pairwise check decoding for ldpc coded two way relay block fading channels"):
  with members:
    - "joint source and relay precoding designs for mimo two way relaying based on mse criterion"
    - "channel coding and decoding in a relay system operated with physical layer network coding"
    - "broadcast capacity region of two phase bidirectional relaying"
    - "joint physical layer coding and network coding for bi directional relaying"
    - "achievable rate regions for bi directional relaying"
    - "physical network coding in two way wireless relay channels"
    - "physical layer network coding"

Connected through hyperedge HE-6 (induced by source paper "compute and forward on a multiaccess relay channel coding and symmetric rate optimization"):
  with members:
    - "an algebraic approach to physical layer network coding"
    - "wireless network information flow a deterministic approach"
    - "lattice codes for the gaussian relay channel decode and forward and compress and forward"
    - "integer forcing linear receivers"
    - "compute and forward harnessing interference through structured codes"
    - "opportunistic communications in an orthogonal multiaccess relay channel"

Connected through hyperedge HE-7 (induced by source paper "alternative awaiting and broadcast for two way relay fading channels"):
  with members:
    - "on achievable rate regions of the asymmetric awgn two way relay channel"
    - "broadcast capacity region of two phase bidirectional relaying"
    - "achievable rate regions for bi directional relaying"
    - "physical network coding in two way wireless relay channels"

Connected through hyperedge HE-8 (induced by source paper "on design of collaborative beamforming for two way relay networks"):
  with members:
    - "grassmannian beamforming for mimo amplify and forward relaying"
    - "network beamforming using relays with perfect channel information"
    - "optimal beamforming for two way multi antenna relay channel with analogue network coding"

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)