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: "alternating minimization for hybrid precoding in multiuser ofdm mmwave systems"
  Abstract: Hybrid precoding is a cost-effective approach to support directional transmissions for millimeter wave (mmWave) communications. While existing works on hybrid precoding mainly focus on single-user single-carrier transmission, in practice multicarrier transmission is needed to combat the much increased bandwidth, and multiuser MIMO can provide additional spatial multiplexing gains. In this paper, we propose a new hybrid precoding structure for multiuser OFDM mmWave systems, which greatly simplifies the hybrid precoder design and is able to approach the performance of the fully digital precoder. In particular, two groups of phase shifters are combined to map the signals from radio frequency (RF) chains to antennas. Then an effective hybrid precoding algorithm based on alternating minimization (AltMin) is proposed, which will alternately optimize the digital and analog precoders. A major algorithmic innovation is a LASSO formulation for the analog precoder, which yields computationally efficient algorithms. Simulation results will show the performance gain of the proposed algorithm. Moreover, it will reveal that canceling the interuser interference is critical in multiuser OFDM hybrid precoding systems.

Connected through hyperedge HE-1 (induced by source paper "robust hybrid precoding for beam misalignment in millimeter wave communications"):
  with members:
    - "secure hybrid analog and digital receive beamforming schemes for efficient interference reduction"
    - "impact of beam misalignment on hybrid beamforming noma for mmwave communications"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "analysis on 60 ghz wireless communications with beamwidth dependent misalignment"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "massive mimo combining with switches"
    - "stochastic geometry modeling and analysis of multi tier millimeter wave cellular networks"

Connected through hyperedge HE-2 (induced by source paper "a hardware efficient analog network structure for hybrid precoding in millimeter wave systems"):
  with members:
    - "hybrid precoding in millimeter wave systems how many phase shifters are needed"
    - "hybrid analog and digital beamforming for mmwave ofdm large scale antenna arrays"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "multi layer precoding a potential solution for full dimensional massive mimo systems"
    - "channel estimation for hybrid architecture based wideband millimeter wave systems"
    - "on the number of rf chains and phase shifters and scheduling design with hybrid analog digital beamforming"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "dynamic subarrays for hybrid precoding in wideband mmwave mimo systems"

Connected through hyperedge HE-3 (induced by source paper "hybrid lisa for wideband multiuser millimeter wave communication systems under beam squint"):
  with members:
    - "multi beam noma for hybrid mmwave systems"
    - "beamforming codebook compensation for beam squint with channel capacity constraint"
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "hybrid analog and digital beamforming for mmwave ofdm large scale antenna arrays"
    - "multiuser millimeter wave beamforming strategies with quantized and statistical csit"
    - "a novel millimeter wave channel simulator and applications for 5g wireless communications"
    - "hybrid lisa precoding for multiuser millimeter wave communications"
    - "effect of wideband beam squint on codebook design in phased array wireless systems"

Connected through hyperedge HE-4 (induced by source paper "hybrid precoding in millimeter wave systems how many phase shifters are needed"):
  with members:
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "on the number of rf chains and phase shifters and scheduling design with hybrid analog digital beamforming"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "hybrid mimo architectures for millimeter wave communications phase shifters or switches"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "low complexity hybrid precoding in massive multiuser mimo systems"

Connected through hyperedge HE-5 (induced by source paper "partially connected hybrid precoding in mm wave systems with dynamic phase shifter networks"):
  with members:
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "what will 5g be"
    - "spatially sparse precoding in millimeter wave mimo systems"

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)