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: "small cell in band wireless backhaul in massive mimo systems a cooperation of next generation techniques"
  Abstract: Massive multiple-input multiple-output (MIMO) systems, dense small-cells (SCs), and full duplex are three candidate techniques for next-generation communication systems. The cooperation of next-generation techniques could offer more benefits, e.g., SC in-band wireless backhaul in massive MIMO systems. In this paper, three strategies of SC in-band wireless backhaul in massive MIMO systems are introduced and compared, i.e., complete time-division duplex (CTDD), zero-division duplex (ZDD), and ZDD with interference rejection (ZDD-IR). Simulation results demonstrate that SC in-band wireless backhaul has the potential to improve the throughput for massive MIMO systems. Specifically, among the three strategies, CTDD is the simplest one and could achieve decent throughput improvement. Depending on conditions, with the self-interference cancellation capability at SCs, ZDD could achieve better throughput than CTDD, even with residual self-interference. Moreover, ZDD-IR requires the additional interference rejection process at the BS compared to ZDD, but it could generally achieve better throughput than CTDD and ZDD.

Connected through hyperedge HE-1 (induced by source paper "integrated access and backhaul optimization for millimeter wave heterogeneous networks"):
  with members:
    - "scheduling and power allocation in self backhauled full duplex small cells"
    - "optimal joint routing and scheduling in millimeter wave cellular networks"
    - "joint backhaul access analysis of full duplex self backhauling heterogeneous networks"
    - "joint downlink cell association and bandwidth allocation for wireless backhauling in two tier hetnets with large scale antenna arrays"
    - "exploiting device to device communications in joint scheduling of access and backhaul for mmwave small cells"
    - "5g wireless backhaul networks challenges and research advances"
    - "enhanced intercell interference coordination challenges in heterogeneous networks"

Connected through hyperedge HE-2 (induced by source paper "5g massive mimo architectures self backhauled small cells versus direct access"):
  with members:
    - "performance analysis for practical unmanned aerial vehicle networks with los nlos transmissions"
    - "performance of massive mimo self backhauling for ultra dense small cell deployments"
    - "performance of dynamic and static tdd in self backhauled millimeter wave cellular networks"
    - "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
    - "joint backhaul access analysis of full duplex self backhauling heterogeneous networks"
    - "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"
    - "the new frontier in ran heterogeneity multi tier drone cells"
    - "performance impact of los and nlos transmissions in dense cellular networks"

Connected through hyperedge HE-3 (induced by source paper "environment aware minimum cost wireless backhaul network planning with full duplex links"):
  with members:
    - "hardware impairments aware transceiver design for full duplex amplify and forward mimo relaying"
    - "hardware impairments aware transceiver design for bidirectional full duplex mimo ofdm systems"
    - "sum rate analysis and optimization of self backhauling based full duplex radio access system"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "hardware impairments aware transceiver for full duplex massive mimo relaying"
    - "full duplex mimo small cell networks performance analysis"
    - "5g wireless backhaul networks challenges and research advances"

Connected through hyperedge HE-4 (induced by source paper "performance of massive mimo self backhauling for ultra dense small cell deployments"):
  with members:
    - "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
    - "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "energy efficient design of mimo heterogeneous networks with wireless backhaul"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-5 (induced by source paper "joint backhaul access analysis of full duplex self backhauling heterogeneous networks"):
  with members:
    - "a linearization technique for self interference cancellation in full duplex radios"
    - "full duplex mimo small cell networks performance analysis"
    - "energy efficient design of mimo heterogeneous networks with wireless backhaul"
    - "tractable model for rate in self backhauled millimeter wave cellular networks"
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "experiment driven characterization of full duplex wireless systems"
    - "a tractable approach to coverage and rate in cellular networks"

Connected through hyperedge HE-6 (induced by source paper "scheduling and power allocation in self backhauled full duplex small cells"):
  with members:
    - "joint backhaul access analysis of full duplex self backhauling heterogeneous networks"
    - "sum rate analysis and optimization of self backhauling based full duplex radio access system"
    - "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"
    - "in band full duplex wireless challenges and opportunities"

Connected through hyperedge HE-7 (induced by source paper "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"):
  with members:
    - "joint downlink cell association and bandwidth allocation for wireless backhauling in two tier hetnets with large scale antenna arrays"
    - "heterogeneous cellular networks using wireless backhaul fast admission control and large system analysis"
    - "5g wireless backhaul networks challenges and research advances"
    - "full duplex cloud radio access networks an information theoretic viewpoint"
    - "optimal user cell association for massive mimo wireless networks"
    - "hybrid full half duplex system analysis in heterogeneous wireless networks"
    - "cognitive and energy harvesting based d2d communication in cellular networks stochastic geometry modeling and analysis"
    - "evolution toward 5g multi tier cellular wireless networks an interference management perspective"

Connected through hyperedge HE-8 (induced by source paper "interference management in 5g reverse tdd hetnets with wireless backhaul a large system analysis"):
  with members:
    - "large system analysis of the energy consumption distribution in multi user mimo systems with mobility"
    - "wireless backhaul networks capacity bound scalability analysis and design guidelines"
    - "linear precoding based on polynomial expansion large scale multi cell mimo systems"
    - "massive mimo for next generation wireless systems"
    - "optimal linear precoding in multi user mimo systems a large system analysis"
    - "what will 5g be"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"
    - "large system analysis of cooperative multi cell downlink transmission via regularized channel inversion with imperfect csit"

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)