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: "code expanded random access for machine type communications"
  Abstract: The random access methods used for support of machine-type communications (MTC) in current cellular standards are derivatives of traditional framed slotted ALOHA and therefore do not support high user loads efficiently. Motivated by the random access method employed in LTE, we propose a novel approach that is able to sustain a wide random access load range, while preserving the physical layer unchanged and incurring minor changes in the medium access control layer. The proposed scheme increases the amount of available contention resources, without resorting to the increase of system resources, such as contention sub-frames and preambles. This increase is accomplished by expanding the contention space to the code domain, through the creation of random access codewords. Specifically, in the proposed scheme, users perform random access by transmitting one or none of the available LTE orthogonal preambles in multiple random access sub-frames, thus creating access codewords that are used for contention. In this way, for the same number of random access sub-frames and orthogonal preambles, the amount of available contention resources is drastically increased, enabling the support of an increased number of MTC users. We present the framework and analysis of the proposed code-expanded random access method and show that our approach supports load regions that are beyond the reach of current systems.

Connected through hyperedge HE-1 (induced by source paper "joint active user detection and channel estimation in massive access systems exploiting reed muller sequences"):
  with members:
    - "reed muller sequences for 5g grant free massive access"
    - "massive connectivity with massive mimo part i device activity detection and channel estimation"
    - "compressive random access using a common overloaded control channel"
    - "random access for machine type communication based on bloom filtering"
    - "reed muller sensing matrices and the lasso"

Connected through hyperedge HE-2 (induced by source paper "a probabilistic approach to model sic based rach mechanism for massive machine type communications in cellular networks"):
  with members:
    - "lte lte a random access for massive machine type communications in smart cities"
    - "intra slot interference cancellation for collision resolution in irregular repetition slotted aloha"

Connected through hyperedge HE-3 (induced by source paper "multiple preambles for high success rate of grant free random access with massive mimo"):
  with members:
    - "grant free massive mtc enabled massive mimo a compressive sensing approach"
    - "success probability of grant free random access with massive mimo"
    - "sparse signal processing for grant free massive connectivity a future paradigm for random access protocols in the internet of things"
    - "a random access protocol for pilot allocation in crowded massive mimo systems"
    - "frameless aloha with reliability latency guarantees"
    - "random pilot and data access in massive mimo for machine type communications"
    - "random access protocols for massive mimo"
    - "a high throughput pilot allocation for m2m communication in crowded massive mimo systems"

Connected through hyperedge HE-4 (induced by source paper "a random access protocol for pilot allocation in crowded massive mimo systems"):
  with members:
    - "random access in uplink massive mimo systems how to exploit asynchronicity and excess antennas"
    - "massive mimo ten myths and one critical question"
    - "random access for massive mimo systems with intra cell pilot contamination"
    - "random access protocol for massive mimo strongest user collision resolution sucr"
    - "massive mimo for crowd scenarios a solution based on random access"
    - "three practical aspects of massive mimo intermittent user activity pilot synchronism and asymmetric deployment"
    - "coded random access applying codes on graphs to design random access protocols"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"

Connected through hyperedge HE-5 (induced by source paper "lte lte a random access for massive machine type communications in smart cities"):
  with members:
    - "massive m2m access with reliability guarantees in lte systems"
    - "probabilistic rateless multiple access for machine to machine communication"

Connected through hyperedge HE-6 (induced by source paper "random access protocol for massive mimo strongest user collision resolution sucr"):
  with members:
    - "massive mimo for crowd scenarios a solution based on random access"
    - "three practical aspects of massive mimo intermittent user activity pilot synchronism and asymmetric deployment"
    - "massive mimo for maximal spectral efficiency how many users and pilots should be allocated"
    - "five disruptive technology directions for 5g"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "pilot contamination and precoding in multi cell tdd systems"

Connected through hyperedge HE-7 (induced by source paper "low rate machine type communication via wireless device to device d2d links"):
  with members:
    - "frameless aloha protocol for wireless networks"
    - "coordinated transmissions to direct and relayed users in wireless cellular systems"
    - "spectrum sharing between cellular and mobile ad hoc networks transmission capacity trade off"

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)