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: "fundamental limits of low density spreading noma with fading"
  Abstract: Spectral efficiency of low-density spreading non-orthogonal multiple access channels in the presence of fading is derived for linear detection with independent decoding as well as optimum decoding. The large system limit, where both the number of users and number of signal dimensions grow with fixed ratio, called load, is considered. In the case of optimum decoding, it is found that low-density spreading underperforms dense spreading for all loads. Conversely, linear detection is characterized by different behaviors in the underloaded vs. overloaded regimes. In particular, it is shown that spectral efficiency changes smoothly as load increases. However, in the overloaded regime, the spectral efficiency of low- density spreading is higher than that of dense spreading.

Connected through hyperedge HE-1 (induced by source paper "non orthogonal multiple access with orthogonal time frequency space signal transmission"):
  with members:
    - "otfs noma an efficient approach for exploiting heterogenous user mobility profiles"
    - "low complexity lmmse receiver for otfs"
    - "robust beamforming design for otfs noma"
    - "on the diversity of uncoded otfs modulation in doubly dispersive channels"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "dynamic user clustering and power allocation for uplink and downlink non orthogonal multiple access noma systems"
    - "otfs orthogonal time frequency space"

Connected through hyperedge HE-2 (induced by source paper "code domain noma in massive mimo when is it needed"):
  with members:
    - "what is the benefit of code domain noma in massive mimo"
    - "what role can noma play in massive mimo"
    - "gaussian message passing for overloaded massive mimo noma"
    - "massive mimo has unlimited capacity"
    - "massive mimo performance tdd versus fdd what do measurements say"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "massive mimo performance evaluation based on measured propagation data"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"

Connected through hyperedge HE-3 (induced by source paper "on the fundamental limits of mimo massive access communication"):
  with members:
    - "fundamental limits of many user mac with finite payloads and fading"
    - "massive mimo unsourced random access"
    - "improved scaling law for activity detection in massive mimo systems"
    - "sparse activity detection for massive connectivity"
    - "massive connectivity with massive mimo part ii achievable rate characterization"
    - "a new scaling law for activity detection in massive mimo systems"
    - "massive connectivity with massive mimo part i device activity detection and channel estimation"
    - "capacity of gaussian many access channels"

Connected through hyperedge HE-4 (induced by source paper "what is the benefit of code domain noma in massive mimo"):
  with members:
    - "what role can noma play in massive mimo"
    - "gaussian message passing for overloaded massive mimo noma"
    - "massive mimo has unlimited capacity"

Connected through hyperedge HE-5 (induced by source paper "fairness and sum rate maximization via joint channel and power allocation in uplink scma networks"):
  with members:
    - "single or multiple frames content delivery for next generation networks"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "modeling and analysis of scma enhanced d2d and cellular hybrid network"
    - "joint downlink base station association and power control for max min fairness computation and complexity"
    - "distributed pricing based user association for downlink heterogeneous cellular networks"
    - "scma for downlink multiple access of 5g wireless networks"
    - "uplink contention based scma for 5g radio access"
    - "scma codebook design"

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)