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: "the application of mimo to non orthogonal multiple access"
  Abstract: This paper considers the application of multiple-input multiple-output (MIMO) techniques to non-orthogonal multiple access (NOMA) systems. A new design of precoding and detection matrices for MIMO-NOMA is proposed and its performance is analyzed for the case with a fixed set of power allocation coefficients. To further improve the performance gap between MIMO-NOMA and conventional orthogonal multiple access schemes, user pairing is applied to NOMA and its impact on the system performance is characterized. More sophisticated choices of power allocation coefficients are also proposed to meet various quality of service requirements. Finally computer simulation results are provided to facilitate the performance evaluation of MIMO-NOMA and also demonstrate the accuracy of the developed analytical results.

Connected through hyperedge HE-1 (induced by source paper "mimo noma networks relying on reconfigurable intelligent surface a signal cancellation based design"):
  with members:
    - "intelligent reflecting surface assisted multiple access with user pairing noma or oma"
    - "enabling panoramic full angle reflection via aerial intelligent reflecting surface"
    - "performance analysis of intelligent reflecting surface assisted noma networks"
    - "miso wireless communication systems via intelligent reflecting surfaces"
    - "large intelligent surface antennas lisa making reflective radios smart"
    - "reflection probability in wireless networks with metasurface coated environmental objects an approach based on random spatial processes"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "channel capacity optimization using reconfigurable intelligent surfaces in indoor mmwave environments"

Connected through hyperedge HE-2 (induced by source paper "lattice coding for downlink multiuser transmission"):
  with members:
    - "downlink non orthogonal multiple access without sic for block fading channels an algebraic rotation approach"
    - "joint pilot and payload power control for uplink mimo noma with mrc sic receivers"
    - "short packet downlink transmission with non orthogonal multiple access"
    - "a multi beam noma framework for hybrid mmwave systems"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "improved decoding and error floor analysis of staircase codes"
    - "performance analysis of a hybrid downlink uplink cooperative noma scheme"
    - "on non orthogonal multiple access with finite alphabet inputs in z channels"

Connected through hyperedge HE-3 (induced by source paper "non orthogonal multiple access noma how it meets 5g and beyond"):
  with members:
    - "securing downlink massive mimo noma networks with artificial noise"
    - "energy efficient joint user rb association and power allocation for uplink hybrid noma oma"
    - "capacity and outage analysis of a dual hop decode and forward relay aided noma scheme"
    - "energy efficient power allocation in uplink mmwave massive mimo with noma"
    - "optimal joint subcarrier and power allocation in noma is strongly np hard"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "a two phase power allocation scheme for crns employing noma"

Connected through hyperedge HE-4 (induced by source paper "noma an information theoretic perspective"):
  with members:
    - "rate splitting multiple access for downlink communication systems bridging generalizing and outperforming sdma and noma"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "optimal beamforming for gaussian mimo wiretap channels with two transmit antennas"
    - "approximate capacity region of the mac ic mac"
    - "gsvd based precoding in mimo systems with integrated services"
    - "non orthogonal multiple access in multi cell networks theory performance and practical challenges"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"

Connected through hyperedge HE-5 (induced by source paper "rate analysis of cell free massive mimo noma with three linear precoders"):
  with members:
    - "what role can noma play in massive mimo"
    - "ubiquitous cell free massive mimo communications"
    - "interplay between noma and other emerging technologies a survey"
    - "downlink spectral efficiency of cell free massive mimo with full pilot zero forcing"
    - "signal processing for mimo noma present and future challenges"
    - "on the total energy efficiency of cell free massive mimo"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "channel hardening and favorable propagation in cell free massive mimo with stochastic geometry"

Connected through hyperedge HE-6 (induced by source paper "securing downlink massive mimo noma networks with artificial noise"):
  with members:
    - "energy efficient joint user rb association and power allocation for uplink hybrid noma oma"
    - "energy efficient power allocation in uplink mmwave massive mimo with noma"
    - "exploiting inter user interference for secure massive non orthogonal multiple access"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "resource allocation for downlink noma systems key techniques and open issues"
    - "noma in 5g systems exciting possibilities for enhancing spectral efficiency"

Connected through hyperedge HE-7 (induced by source paper "power efficient irs assisted noma"):
  with members:
    - "multi antenna covert communications in random wireless networks"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "smart radio environments empowered by ai reconfigurable meta surfaces an idea whose time has come"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"
    - "a simple design of irs noma transmission"
    - "a speculative study on 6g"

Connected through hyperedge HE-8 (induced by source paper "non orthogonal multiple access for visible light communications with ambient light and user mobility"):
  with members:
    - "non orthogonal multiple access common myths and critical questions"
    - "precoded chebyshev nlms based pre distorter for nonlinear led compensation in noma vlc"
    - "non orthogonal multiple access for visible light communications"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"

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)