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: "on optimal precoding in linear vector gaussian channels with arbitrary input distribution"
  Abstract: The design of the precoder the maximizes the mutual information in linear vector Gaussian channels with an arbitrary input distribution is studied. Precisely, the precoder optimal left singular vectors and singular values are derived. The characterization of the right singular vectors is left, in general, as an open problem whose computational complexity is then studied in three cases: Gaussian signaling, low SNR, and high SNR. For the Gaussian signaling case and the low SNR regime, the dependence of the mutual information on the right singular vectors vanishes, making the optimal precoder design problem easy to solve. In the high SNR regime, however, the dependence on the right singular vectors cannot be avoided and we show the difficulty of computing the optimal precoder through an NP-hardness analysis.

Connected through hyperedge HE-1 (induced by source paper "measurement matrix design for phase retrieval based on mutual information"):
  with members:
    - "non convex phase retrieval from stft measurements"
    - "stft phase retrieval uniqueness guarantees and recovery algorithms"
    - "intensity only optical compressive imaging using a multiply scattering material and a double phase retrieval approach"
    - "almost lossless analog compression without phase information"
    - "phase retrieval via wirtinger flow theory and algorithms"
    - "phasecode fast and efficient compressive phase retrieval based on sparse graph codes"
    - "phase retrieval from coded diffraction patterns"
    - "phase retrieval stability and recovery guarantees"

Connected through hyperedge HE-2 (induced by source paper "mimo mutli cell processing optimal precoding and power allocation"):
  with members:
    - "piggybacking codes for network coding the high low snr regime"
    - "multiple access gaussian channels with arbitrary inputs optimal precoding and power allocation"
    - "multi cell processing with limited cooperation a novel framework to timely designs and reduced feedback with general inputs"
    - "fundamental limits of cooperation"
    - "mutual information and minimum mean square error in gaussian channels"

Connected through hyperedge HE-3 (induced by source paper "a survey on mimo transmission with discrete input signals technical challenges advances and future trends"):
  with members:
    - "asymptotic performance analysis of a k hop amplify and forward relay mimo channel"
    - "iterative distributed minimum total mse approach for secure communications in mimo interference channels"
    - "asymptotic analysis of su mimo channels with transmitter noise and mismatched joint decoding"
    - "secure massive mimo transmission with an active eavesdropper"
    - "interference aligned space time transmission with diversity for the 2 times 2 x network"
    - "space time encoded miso broadcast channel with outdated csit an error rate and diversity performance analysis"
    - "high snr asymptotics of mutual information for discrete constellations with applications to bicm"
    - "differential distributed space time coding with imperfect synchronization in frequency selective channels"

Connected through hyperedge HE-4 (induced by source paper "effective capacity in mimo channels with arbitrary inputs"):
  with members:
    - "the world s first real time testbed for massive mimo design implementation and validation"
    - "backlog and delay reasoning in harq systems"
    - "linear precoding for the mimo multiple access channel with finite alphabet inputs and statistical csi"
    - "massive mimo systems with non ideal hardware energy efficiency estimation and capacity limits"
    - "massive mimo for next generation wireless systems"
    - "what will 5g be"
    - "linear mimo precoding in jointly correlated fading multiple access channels with finite alphabet signaling"
    - "on the impact of hardware impairments on massive mimo"

Connected through hyperedge HE-5 (induced by source paper "low complexity mimo precoding for finite alphabet signals"):
  with members:
    - "linear precoding for mimo channels with qam constellations and reduced complexity"
    - "secure massive mimo transmission with an active eavesdropper"
    - "transmit designs for the mimo broadcast channel with statistical csi"
    - "five disruptive technology directions for 5g"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "on capacity of large scale mimo multiple access channels with distributed sets of correlated antennas"
    - "precoding by pairing subchannels to increase mimo capacity with discrete input alphabets"
    - "statistical eigenmode transmission over jointly correlated mimo channels"

Connected through hyperedge HE-6 (induced by source paper "linear precoding for mimo channels with qam constellations and reduced complexity"):
  with members:
    - "low complexity mimo precoding with discrete signals and statistical csi"
    - "linear precoding for the mimo multiple access channel with finite alphabet inputs and statistical csi"
    - "diversity analysis of bit interleaved coded multiple beamforming with orthogonal frequency division multiplexing"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "constellation precoded multiple beamforming"
    - "pilot contamination and precoding in multi cell tdd systems"

Connected through hyperedge HE-7 (induced by source paper "linear precoding for the mimo multiple access channel with finite alphabet inputs and statistical csi"):
  with members:
    - "performance limits of massive mimo systems based on bayes optimal inference"
    - "massive mimo for next generation wireless systems"
    - "transmit designs for the mimo broadcast channel with statistical csi"
    - "a novel power allocation scheme for two user gmac with finite input constellations"
    - "large system analysis of correlated mimo multiple access channels with arbitrary signaling in the presence of interference"
    - "linear precoder design for mimo interference channels with finite alphabet signaling"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "a deterministic equivalent for the analysis of correlated mimo multiple access channels"

Connected through hyperedge HE-8 (induced by source paper "multi cell processing with limited cooperation a novel framework to timely designs and reduced feedback with general inputs"):
  with members:
    - "multiple access gaussian channels with arbitrary inputs optimal precoding and power allocation"
    - "degrees of freedom of time correlated miso broadcast channel with delayed csit"
    - "fundamental limits of cooperation"
    - "completely stale transmitter channel state information is still very useful"
    - "mutual information and minimum mean square error in gaussian channels"

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)