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 power and antenna selection optimization in large cloud radio access networks"
  Abstract: Large multiple-input multiple-output (MIMO) networks promise high energy efficiency, i.e., much less power is required to achieve the same capacity compared to the conventional MIMO networks if perfect channel state information (CSI) is available at the transmitter. However, in such networks, huge overhead is required to obtain full CSI especially for Frequency-Division Duplex (FDD) systems. To reduce overhead, we propose a downlink antenna selection scheme, which selects S antennas from M > S transmit antennas based on the large scale fading to serve K ≤ S users in large distributed MIMO networks employing regularized zero-forcing (RZF) precoding. In particular, we study the joint optimization of antenna selection, regularization factor, and power allocation to maximize the average weighted sum-rate. This is a mixed combinatorial and non-convex problem whose objective and constraints have no closed-form expressions. We apply random matrix theory to derive asymptotically accurate expressions for the objective and constraints. As such, the joint optimization problem is decomposed into subproblems, each of which is solved by an efficient algorithm. In addition, we derive structural solutions for some special cases and show that the capacity of very large distributed MIMO networks scales as O(KlogM) when M→∞ with K, S fixed. Simulations show that the proposed scheme achieves significant performance gain over various baselines.

Connected through hyperedge HE-1 (induced by source paper "stochastic successive convex optimization for two timescale hybrid precoding in massive mimo"):
  with members:
    - "joint power allocation and user association optimization for massive mimo systems"
    - "a parallel decomposition method for nonconvex stochastic multi agent optimization problems"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "hybrid beamforming for massive mimo a survey"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "hierarchical interference mitigation for massive mimo cellular networks"
    - "low complexity hybrid precoding in massive multiuser mimo systems"

Connected through hyperedge HE-2 (induced by source paper "energy efficient downlink transmission for multicell massive das with pilot contamination"):
  with members:
    - "joint power allocation and user association optimization for massive mimo systems"
    - "asymptotic orthogonality analysis of time domain sparse massive mimo channels"
    - "interference management in 5g reverse tdd hetnets with wireless backhaul a large system analysis"
    - "large scale mimo relaying techniques for physical layer security af or df"
    - "large system analysis of cognitive radio network via partially projected regularized zero forcing precoding"
    - "impact of transceiver power consumption on the energy efficiency of zero forcing detector in massive mimo systems"
    - "massive mimo for next generation wireless systems"
    - "what will 5g be"

Connected through hyperedge HE-3 (induced by source paper "recent advances in cloud radio access networks system architectures key techniques and open issues"):
  with members:
    - "fronthaul compression and precoding design for c rans over ergodic fading channels"
    - "optimal fronthaul quantization for cloud radio positioning"
    - "inter tier interference suppression in heterogeneous cloud radio access networks"
    - "contract based interference coordination in heterogeneous cloud radio access networks"
    - "are heterogeneous cloud based radio access networks cost effective"
    - "energy efficient resource assignment and power allocation in heterogeneous cloud radio access networks"
    - "cooperative interference mitigation and handover management for heterogeneous cloud small cell networks"
    - "fronthaul constrained cloud radio access networks insights and challenges"

Connected through hyperedge HE-4 (induced by source paper "energy efficient resource allocation optimization for multimedia heterogeneous cloud radio access networks"):
  with members:
    - "inter tier interference suppression in heterogeneous cloud radio access networks"
    - "fronthaul constrained cloud radio access networks insights and challenges"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "heterogeneous cloud radio access networks a new perspective for enhancing spectral and energy efficiencies"
    - "cache enabled opportunistic cooperative mimo for video streaming in wireless systems"
    - "energy efficiency and spectral efficiency tradeoff in device to device d2d communications"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"
    - "group sparse beamforming for green cloud ran"

Connected through hyperedge HE-5 (induced by source paper "locally orthogonal training design for cloud rans based on graph coloring"):
  with members:
    - "rrh based massive mimo with on the fly pilot contamination control"
    - "cell free massive mimo versus small cells"
    - "selective uplink training for massive mimo systems"
    - "superimposed pilots are superior for mitigating pilot contamination in massive mimo part i theory and channel estimation"
    - "fundamental limits of training based multiuser mimo systems"
    - "training design and channel estimation in uplink cloud radio access networks"
    - "dynamic nested clustering for parallel phy layer processing in cloud rans"
    - "blind pilot decontamination"

Connected through hyperedge HE-6 (induced by source paper "free deterministic equivalents for the analysis of mimo multiple access channel"):
  with members:
    - "channel acquisition for massive mimo ofdm with adjustable phase shift pilots"
    - "an overview of transmission theory and techniques of large scale antenna systems for 5g wireless communications"
    - "secure massive mimo transmission with an active eavesdropper"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "pilot beam pattern design for channel estimation in massive mimo systems"
    - "massive mimo for next generation wireless systems"
    - "on capacity of large scale mimo multiple access channels with distributed sets of correlated antennas"
    - "random beamforming over quasi static and fading channels a deterministic equivalent approach"

Connected through hyperedge HE-7 (induced by source paper "inter tier interference suppression in heterogeneous cloud radio access networks"):
  with members:
    - "fronthaul constrained cloud radio access networks insights and challenges"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "comp meets smart grid a new communication and energy cooperation paradigm"
    - "heterogeneous cloud radio access networks a new perspective for enhancing spectral and energy efficiencies"
    - "ergodic capacity analysis of remote radio head associations in cloud radio access networks"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"
    - "multi user linear precoding for multi polarized massive mimo system under imperfect csit"
    - "group sparse beamforming for green cloud ran"

Connected through hyperedge HE-8 (induced by source paper "downlink rate analysis for virtual cell based large scale distributed antenna systems"):
  with members:
    - "spectral efficiency of dynamic coordinated beamforming a stochastic geometry approach"
    - "a comparative study of downlink mimo cellular networks with co located and distributed base station antennas"
    - "what will 5g be"
    - "energy efficient large scale distributed antenna system l das for multiple users"
    - "interference coordination random clustering and adaptive limited feedback"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "asymptotic rate analysis of downlink multi user systems with co located and distributed antennas"
    - "networked mimo with clustered linear precoding"

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)