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: "optimal space time codes for the mimo amplify and forward cooperative channel"
  Abstract: In this work, we extend the non-orthogonal amplify-and-forward (NAF) cooperative diversity scheme to the MIMO channel. A family of space-time block codes for a half-duplex MIMO NAF fading cooperative channel with N relays is constructed. The code construction is based on the non-vanishing determinant criterion (NVD) and is shown to achieve the optimal diversity-multiplexing tradeoff (DMT) of the channel. We provide a general explicit algebraic construction, followed by some examples. In particular, in the single relay case, it is proved that the Golden code and the 4x4 Perfect code are optimal for the single-antenna and two-antenna case, respectively. Simulation results reveal that a significant gain (up to 10dB) can be obtained with the proposed codes, especially in the single-antenna case.

Connected through hyperedge HE-1 (induced by source paper "unmanned aerial vehicle assisted cellular communication"):
  with members:
    - "massive mimo for communications with drone swarms"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"

Connected through hyperedge HE-2 (induced by source paper "on fast decodable algebraic space time codes"):
  with members:
    - "minimizing the complexity of fast sphere decoding of stbcs"
    - "maximal orders in the design of dense space time lattice codes"

Connected through hyperedge HE-3 (induced by source paper "fast decodable space time codes for the n relay and multiple access mimo channel"):
  with members:
    - "constructions of fast decodable distributed space time codes"
    - "bounds on fast decodability of space time block codes skew hermitian matrices and azumaya algebras"
    - "algebraic codes and a new physical layer transmission protocol for wireless distributed storage systems"
    - "fast decodable asymmetric space time codes from division algebras"
    - "iterated space time code constructions from cyclic algebras"
    - "algebraic fast decodable relay codes for distributed communications"
    - "quadratic forms and space time block codes from generalized quaternion and biquaternion algebras"
    - "minimizing the complexity of fast sphere decoding of stbcs"

Connected through hyperedge HE-4 (induced by source paper "almost universal codes for fading wiretap channels"):
  with members:
    - "almost universal codes achieving ergodic mimo capacity within a constant gap"
    - "probability estimates for fading and wiretap channels from ideal class zeta functions"
    - "number field lattices achieve gaussian and rayleigh channel capacity within a constant gap"
    - "semantically secure lattice codes for the gaussian wiretap channel"
    - "on secrecy capacity of fast fading mimome wiretap channels with statistical csit"
    - "on secrecy capacity of fast fading multiple input wiretap channels with statistical csit"
    - "strong secrecy on the binary erasure wiretap channel using large girth ldpc codes"
    - "an error probability approach to mimo wiretap channels"

Connected through hyperedge HE-5 (induced by source paper "study of buffer aided distributed space time coding for cooperative wireless networks"):
  with members:
    - "a buffer aided successive opportunistic relay selection scheme with power adaptation and inter relay interference cancellation for cooperative diversity systems"
    - "adaptive reduced rank receive processing based on minimum symbol error rate criterion for large scale multiple antenna systems"
    - "direction finding algorithms based on joint iterative subspace optimization"
    - "buffer aided relaying with adaptive link selection"
    - "buffer aided relaying with adaptive link selection fixed and mixed rate transmission"
    - "adaptive distributed space time coding based on adjustable code matrices for cooperative mimo relaying systems"
    - "an efficient adaptive distributed space time coding scheme for cooperative relaying"
    - "a simple cooperative diversity method based on network path selection"

Connected through hyperedge HE-6 (induced by source paper "almost universal codes achieving ergodic mimo capacity within a constant gap"):
  with members:
    - "polar codes and polar lattices for independent fading channels"
    - "algebraic lattice codes achieve the capacity of the compound block fading channel"
    - "almost universal codes for fading wiretap channels"
    - "division algebra codes achieve mimo block fading channel capacity within a constant gap"
    - "number field lattices achieve gaussian and rayleigh channel capacity within a constant gap"
    - "precoded integer forcing universally achieves the mimo capacity to within a constant gap"
    - "inverse determinant sums and connections between fading channel information theory and algebra"
    - "dispersion analysis of infinite constellations in ergodic fading channels"

Connected through hyperedge HE-7 (induced by source paper "an error event sensitive tradeoff between rate and coding gain in mimo mac"):
  with members:
    - "sphere decoding complexity exponent for decoding full rate codes over the quasi static mimo channel"
    - "dmt optimality of lr aided linear decoders for a general class of channels lattice designs and system models"
    - "remarks on the criteria of constructing mimo mac dmt optimal codes"
    - "performance of mmse mimo receivers a large n analysis for correlated channels"
    - "on the decay of the determinants of multiuser mimo lattice codes"
    - "distributed space time block codes for the mimo multiple access channel"
    - "maximal orders in the design of dense space time lattice codes"
    - "diversity multiplexing tradeoff in selective fading multiple access mimo channels"

Connected through hyperedge HE-8 (induced by source paper "constructions of fast decodable distributed space time codes"):
  with members:
    - "fast decodable asymmetric space time codes from division algebras"
    - "iterated space time code constructions from cyclic algebras"
    - "algebraic fast decodable relay codes for distributed communications"
    - "on fast decodable space time block codes"

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)