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: "user load analysis and pilot sequence design for multi cell massive mimo networks"
  Abstract: We propose a novel algorithm to design user load-achieving pilot sequences that mitigate pilot contamination in multi-cell massive multiple-input multiple-output (MIMO) networks. To this end, we first derive expressions for the user load and the load region of the network considering both small-scale and large-scale propagation effects. We then develop the pilot sequence algorithm for multi-cell massive MIMO networks as per the rules of generalized Welch bound equality design. Notably, we find that our algorithm and the corresponding downlink power allocation ensure that the user load is achieved when the signal-to-interference-plus-noise ratio (SINR) requirements for the users lie within the load region. Furthermore, we demonstrate the performance advantage of our proposed design relative to the existing designs, in terms of a larger load region and a higher maximum permitted SINR. Finally, we show that our proposed design can satisfy the pre-defined SINR requirements for users with a finite number of antennas at the base station (BS), while the existing designs cannot satisfy the same requirements even with an infinite number of antennas at the BS.

Connected through hyperedge HE-1 (induced by source paper "on the pilot contamination attack in multi cell multiuser massive mimo networks"):
  with members:
    - "pilot spoofing attack by multiple eavesdroppers"
    - "multiple antennas secure transmission under pilot spoofing and jamming attack"
    - "active attack on user load achieving pilot design in massive mimo networks"
    - "the world s first real time testbed for massive mimo design implementation and validation"
    - "multi cell multiuser massive mimo networks user capacity analysis and pilot design"
    - "massive mimo pilot retransmission strategies for robustification against jamming"
    - "subverting massive mimo by smart jamming"
    - "power allocation schemes for multicell massive mimo systems"

Connected through hyperedge HE-2 (induced by source paper "active attack on user load achieving pilot design in massive mimo networks"):
  with members:
    - "multi cell multiuser massive mimo networks user capacity analysis and pilot design"
    - "mitigating pilot contamination through location aware pilot assignment in massive mimo networks"
    - "massive mimo for next generation wireless systems"
    - "blind pilot decontamination"
    - "five disruptive technology directions for 5g"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "pilot contamination and precoding in multi cell tdd systems"

Connected through hyperedge HE-3 (induced by source paper "multi cell multiuser massive mimo networks user capacity analysis and pilot design"):
  with members:
    - "performance analysis and location optimization for massive mimo systems with circularly distributed antennas"
    - "graph coloring based pilot allocation to mitigate pilot contamination for multi cell massive mimo systems"
    - "power allocation schemes for multicell massive mimo systems"
    - "fundamental limits of training based multiuser mimo systems"
    - "pilot signal design for massive mimo systems a received signal to noise ratio based approach"
    - "massive mimo performance evaluation based on measured propagation data"
    - "smart pilot assignment for massive mimo"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-4 (induced by source paper "mitigating pilot contamination through location aware pilot assignment in massive mimo networks"):
  with members:
    - "location based beamforming for enhancing secrecy in rician wiretap channels"
    - "multi cell multiuser massive mimo networks user capacity analysis and pilot design"
    - "user capacity analysis and pilot design for multi cell multiuser massive mimo networks"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"
    - "blind pilot decontamination"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "pilot contamination and precoding in multi cell tdd systems"

Connected through hyperedge HE-5 (induced by source paper "user capacity analysis and pilot design for multi cell multiuser massive mimo networks"):
  with members:
    - "performance analysis and location optimization for massive mimo systems with circularly distributed antennas"
    - "graph coloring based pilot allocation to mitigate pilot contamination for multi cell massive mimo systems"
    - "power allocation schemes for multicell massive mimo systems"
    - "pilot signal design for massive mimo systems a received signal to noise ratio based approach"
    - "massive mimo performance evaluation based on measured propagation data"
    - "smart pilot assignment for massive mimo"
    - "massive mimo for next generation wireless systems"
    - "blind pilot decontamination"

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)