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: "an experimental investigation of simo mimo interference alignment ia and coordinated multi point comp"
  Abstract: In this paper we present experimental implementations of interference alignment (IA) and coordinated multi-point transmission (CoMP). We provide results for a system with three base-stations and three mobile-stations all having two antennas. We further employ OFDM modulation, with high-order constellations, and measure many positions both line-of-sight and non-line-of-sight under interference limited conditions. We find the CoMP system to perform better than IA at the cost of a higher back-haul capacity requirement. During the measurements we also logged the channel estimates for off-line processing. We use these channel estimates to calculate the performance under ideal conditions. The performance estimates obtained this way is substantially higher than what is actually observed in the end-to-end transmissions---in particular in the CoMP case where the theoretical performance is very high. We find the reason for this discrepancy to be the impact of dirty-RF effects such as phase-noise and non-linearities. We are able to model the dirty-RF effects to some extent. These models can be used to simulate more complex systems and still account for the dirty-RF effects (e.g., systems with tens of mobiles and base-stations). Both IA and CoMP perform better than reference implementations of single-user SIMO and MIMO in our measurements.

Connected through hyperedge HE-1 (induced by source paper "scalable and passive wireless network clock synchronization in los environments"):
  with members:
    - "joint ranging and clock parameter estimation by wireless round trip time measurements"
    - "experimental demonstration of nanosecond accuracy wireless network synchronization"
    - "cooperative synchronization in wireless networks"
    - "fundamentals of large sensor networks connectivity capacity clocks and computation"
    - "femtocell networks a survey"

Connected through hyperedge HE-2 (induced by source paper "interference alignment practical challenges and test bed implementation"):
  with members:
    - "real interference alignment exploiting the potential of single antenna systems"
    - "interference alignment ia and coordinated multi point comp with ieee802 11ac feedback compression testbed results"
    - "completely stale transmitter channel state information is still very useful"
    - "interference alignment under limited feedback for mimo interference channels"
    - "interference alignment with limited feedback"
    - "ergodic interference alignment"

Connected through hyperedge HE-3 (induced by source paper "interference alignment ia and coordinated multi point comp overheads and rf impairments testbed results"):
  with members:
    - "interference alignment ia and coordinated multi point comp with ieee802 11ac feedback compression testbed results"
    - "optimal coordinated beamforming in the multicell downlink with transceiver impairments"
    - "on feasibility of interference alignment in mimo interference networks"
    - "on feasibility of interference alignment in mimo interference networks"
    - "approaching the capacity of wireless networks through distributed interference alignment"

Connected through hyperedge HE-4 (induced by source paper "experimental evaluation of interference alignment for broadband wlan systems"):
  with members:
    - "on the degrees of freedom achievable through interference alignment in a mimo interference channel"
    - "a feasibility test for linear interference alignment in mimo channels with constant coefficients"
    - "mimo transmission with residual transmit rf impairments"
    - "on feasibility of interference alignment in mimo interference networks"
    - "interference alignment with limited feedback"
    - "on feasibility of interference alignment in mimo interference networks"

Connected through hyperedge HE-5 (induced by source paper "interference alignment ia and coordinated multi point comp with ieee802 11ac feedback compression testbed results"):
  with members:
    - "interference alignment under limited feedback for mimo interference channels"
    - "approaching the capacity of wireless networks through distributed interference 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)