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 spectrum management in multiuser interference channels"
  Abstract: In this paper, we study the non-convex problem of continuous frequency optimal spectrum management in multiuser frequency selective interference channels. Firstly, a simple pairwise channel condition for FDMA schemes to achieve all Pareto optimal points of the rate region is derived. It enables fully distributed global optimal decision making on whether any two users should use orthogonal channels. Next, we present in detail an analytical solution to finding the global optimum of sum-rate maximization in two-user symmetric flat channels. Generalizing this solution to frequency selective channels, a convex optimization is established that solves the global optimum. Finally, we show that our method generalizes to K-user (K>=2) weighted sum-rate maximization in asymmetric frequency selective channels, and transform this classic non-convex optimization in the primal domain to an equivalent convex optimization. The complexity is shown to be separable in its dependence on the channel parameters and the power constraints.

Connected through hyperedge HE-1 (induced by source paper "spectrum optimization in multi user multi carrier systems with iterative convex and nonconvex approximation methods"):
  with members:
    - "refim a practical interference management in heterogeneous wireless access networks"
    - "power control in two tier femtocell networks"
    - "a new outer bound and the noisy interference sum rate capacity for gaussian interference channels"
    - "gaussian interference channel capacity to within one bit"
    - "the capacity region of a class of discrete degraded interference 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)