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: "joint unitary triangularization for gaussian multi user mimo networks"
  Abstract: The problem of transmitting a common message to multiple users over the Gaussian multiple-input multiple-output broadcast channel is considered, where each user is equipped with an arbitrary number of antennas. A closed-loop scenario is assumed, for which a practical capacity-approaching scheme is developed. By applying judiciously chosen unitary operations at the transmit and receive nodes, the channel matrices are triangularized so that the resulting matrices have equal diagonals, up to a possible multiplicative scalar factor. This, along with the utilization of successive interference cancellation, reduces the coding and decoding tasks to those of coding and decoding over the single-antenna additive white Gaussian noise channel. Over the resulting effective channel, any off-the-shelf code may be used. For the two-user case, it was recently shown that such joint unitary triangularization is always possible. In this paper, it is shown that for more than two users, it is necessary to carry out the unitary linear processing jointly over multiple channel uses, i.e., space–time processing is employed. It is further shown that exact triangularization, where all resulting diagonals are equal, is still not always possible, and appropriate conditions for the existence of such are established for certain cases. When exact triangularization is not possible, an asymptotic construction is proposed, that achieves the desired property of equal diagonals up to edge effects that can be made arbitrarily small, at the price of processing a sufficiently large number of channel uses together.

Connected through hyperedge HE-1 (induced by source paper "outage behavior of integer forcing with random unitary pre processing"):
  with members:
    - "successive integer forcing and its sum rate optimality"
    - "precoded integer forcing universally achieves the mimo capacity to within a constant gap"
    - "on complex lll algorithm for integer forcing linear receivers"
    - "the approximate sum capacity of the symmetric gaussian k user interference channel"
    - "integer forcing linear receivers"
    - "compute and forward harnessing interference through structured codes"

Connected through hyperedge HE-2 (induced by source paper "outage behavior of randomly precoded integer forcing over mimo channels"):
  with members:
    - "successive integer forcing and its sum rate optimality"
    - "precoded integer forcing universally achieves the mimo capacity to within a constant gap"
    - "on complex lll algorithm for integer forcing linear receivers"
    - "a simple proof for the existence of good pairs of nested lattices"
    - "integer forcing linear receivers"

Connected through hyperedge HE-3 (induced by source paper "the dirty mimo multiple access channel"):
  with members:
    - "joint unitary triangularization for mimo networks"
    - "multiple input multiple output two way relaying a space division approach"
    - "physical layer mimo relaying"
    - "lattice strategies for the dirty multiple access channel"

Connected through hyperedge HE-4 (induced by source paper "the mimo wiretap channel decomposed"):
  with members:
    - "optimal signaling for secure communications over gaussian mimo wiretap channels"
    - "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"
    - "semantically secure coding scheme achieving the capacity of a gaussian wiretap channel"
    - "joint unitary triangularization for mimo networks"
    - "achieving the secrecy capacity of wiretap channels using polar codes"
    - "strong secrecy from channel resolvability"
    - "construction of wiretap codes from ordinary channel codes"
    - "the secrecy capacity of the mimo wiretap channel"

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)