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: "spatial degrees of freedom of the multicell mimo multiple access channel"
  Abstract: We consider a homogeneous multiple cellular scenario with multiple users per cell, i.e., $K\geq 1$ where $K$ denotes the number of users in a cell. In this scenario, a degrees of freedom outer bound as well as an achievable scheme that attains the degrees of freedom outer bound of the multicell multiple access channel (MAC) with constant channel coefficients are investigated. The users have $M$ antennas, and the base stations are equipped with $N$ antennas. The found outer bound is general in that it characterizes a degrees of freedom upper bound for $K\geq 1$ and $L>1$ where $L$ denotes the number of cells. The achievability of the degrees of freedom outer bound is studied for two cell case (i.e., L=2). The achievable schemes that attains the degrees of freedom outer bound for L=2 are based on two approaches. The first scheme is a simple zero forcing with $M=K\beta+\beta$ and $N=K\beta$, and the second approach is null space interference alignment with $M=K\beta$ and $N=K\beta+\beta$ where $\beta>0$ is a positive integer.

Connected through hyperedge HE-1 (induced by source paper "degrees of freedom and achievable rate of wide band multi cell multiple access channels with no csit"):
  with members:
    - "interference free ofdm rethinking ofdm for interference networks with inter symbol interference"
    - "spectral efficiency of dynamic coordinated beamforming a stochastic geometry approach"
    - "topological interference management through index coding"
    - "a practical cooperative multicell mimo ofdma network based on rank coordination"
    - "opportunistic interference alignment for mimo interfering multiple access channels"
    - "optimal use of current and outdated channel state information degrees of freedom of the miso bc with mixed csit"
    - "not too delayed csit achieves the optimal degrees of freedom"
    - "a new outer bound via interference localization and the degrees of freedom regions of mimo interference networks with no csit"

Connected through hyperedge HE-2 (induced by source paper "sum rate maximization in sub 28 ghz millimeter wave mimo interfering networks"):
  with members:
    - "subspace estimation and decomposition for large millimeter wave mimo systems"
    - "a survey of millimeter wave mmwave communications for 5g opportunities and challenges"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "decomposition by partial linearization parallel optimization of multi agent systems"
    - "what will 5g be"
    - "millimeter wave cellular wireless networks potentials and challenges"
    - "millimeter wave beamforming for wireless backhaul and access in small cell networks"
    - "interference alignment a one sided approach"

Connected through hyperedge HE-3 (induced by source paper "separability and sum rate maximization in mimo interfering networks"):
  with members:
    - "a survey of millimeter wave mmwave communications for 5g opportunities and challenges"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "decomposition by partial linearization parallel optimization of multi agent systems"
    - "millimeter wave cellular wireless networks potentials and challenges"
    - "millimeter wave beamforming for wireless backhaul and access in small cell networks"
    - "cooperative algorithms for mimo interference channels"
    - "on feasibility of interference alignment in mimo interference networks"
    - "on feasibility of interference alignment in mimo interference networks"

Connected through hyperedge HE-4 (induced by source paper "retrospective interference alignment for two cell uplink mimo cellular networks with delayed csit"):
  with members:
    - "on the degrees of freedom of k user siso interference and x channels with delayed csit"
    - "linear degrees of freedom of the mimo x channel with delayed csit"
    - "completely stale transmitter channel state information is still very useful"
    - "downlink interference alignment"

Connected through hyperedge HE-5 (induced by source paper "interference alignment for multicell multiuser mimo uplink channels"):
  with members:
    - "degrees of freedom of full duplex multiantenna cellular networks"
    - "cellular interference alignment omni directional antennas and asymmetric configurations"
    - "real interference alignment exploiting the potential of single antenna systems"
    - "degrees of freedom of uplink downlink multiantenna cellular networks"
    - "cellular interference alignment"
    - "on the feasibility of linear interference alignment for mimo interference broadcast channels with constant coefficients"
    - "genie chain and degrees of freedom of symmetric mimo interference broadcast channels"
    - "degrees of freedom of mimo cellular networks decomposition and linear beamforming design"

Connected through hyperedge HE-6 (induced by source paper "grouping based interference alignment with ia cell assignment in multi cell mimo mac under limited feedback"):
  with members:
    - "user selection in mimo interfering broadcast channels"
    - "what will 5g be"
    - "limited feedback design for interference alignment on mimo interference networks with heterogeneous path loss and spatial correlations"
    - "interference alignment with quantized grassmannian feedback in the k user constant mimo interference channel"
    - "low complexity sum rate maximization for single and multiple stream mimo af relay networks"
    - "on feasibility of interference alignment in mimo interference networks"
    - "downlink interference alignment"
    - "interference alignment under limited feedback for mimo interference channels"

Connected through hyperedge HE-7 (induced by source paper "on non integer linear degrees of freedom of constant two cell mimo cellular networks"):
  with members:
    - "genie tree and degrees of freedom of the symmetric mimo interfering broadcast channel"
    - "on the feasibility of linear interference alignment for mimo interference broadcast channels with constant coefficients"
    - "genie chain and degrees of freedom of symmetric mimo interference broadcast channels"
    - "maximum rate transmission with improved diversity gain for interference networks"
    - "subspace alignment chains and the degrees of freedom of the three user mimo interference channel"
    - "downlink interference alignment"
    - "interference alignment with asymmetric complex signaling settling the host madsen nosratinia conjecture"

Connected through hyperedge HE-8 (induced by source paper "genie tree and degrees of freedom of the symmetric mimo interfering broadcast channel"):
  with members:
    - "genie chains exploring outer bounds on the degrees of freedom of mimo interference networks"
    - "feasibility of interference alignment for the mimo interference channel"
    - "the feasibility conditions for interference alignment in mimo networks"
    - "alternating rate profile optimization in single stream mimo interference channels"
    - "on the feasibility of linear interference alignment for mimo interference broadcast channels with constant coefficients"
    - "degrees of freedom of mimo cellular networks decomposition and linear beamforming design"
    - "on the degrees of freedom achievable through interference alignment in a mimo interference channel"
    - "a feasibility test for linear interference alignment in mimo channels with constant coefficients"

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)