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: "channel uncertainty in ultra wideband communication systems"
  Abstract: Wide band systems operating over multipath channels may spread their power over bandwidth if they use duty cycle. Channel uncertainty limits the achievable data rates of power constrained wide band systems; Duty cycle transmission reduces the channel uncertainty because the receiver has to estimate the channel only when transmission takes place. The optimal choice of the fraction of time used for transmission depends on the spectral efficiency of the signal modulation. The general principle is demonstrated by comparing the channel conditions that allow different modulations to achieve the capacity in the limit. Direct sequence spread spectrum and pulse position modulation systems with duty cycle achieve the channel capacity, if the increase of the number of channel paths with the bandwidth is not too rapid. The higher spectral efficiency of the spread spectrum modulation lets it achieve the channel capacity in the limit, in environments where pulse position modulation with non-vanishing symbol time cannot be used because of the large number of channel paths.

Connected through hyperedge HE-1 (induced by source paper "spectral efficiency of random time hopping cdma"):
  with members:
    - "what will 5g be"
    - "bounds on the sum capacity of synchronous binary cdma channels"
    - "tight bounds on the capacity of binary input random cdma systems"
    - "sparsely spread cdma a statistical mechanics based analysis"
    - "analysis of belief propagation for non linear problems the example of cdma or how to prove tanaka s formula"
    - "randomly spread cdma asymptotics via statistical physics"

Connected through hyperedge HE-2 (induced by source paper "bounds on the capacity of ofdm underspread frequency selective fading channels"):
  with members:
    - "noncoherent capacity of underspread fading channels"
    - "low snr capacity of noncoherent fading channels"
    - "on the sensitivity of noncoherent capacity to the channel model"
    - "capacity results for block stationary gaussian fading channels with a peak power constraint"
    - "capacity per unit energy of fading channels with a peak constraint"

Connected through hyperedge HE-3 (induced by source paper "noncoherent capacity of underspread fading channels"):
  with members:
    - "low snr capacity of noncoherent fading channels"
    - "on the sensitivity of noncoherent capacity to the channel model"
    - "multipath channels of bounded capacity"
    - "capacity results for block stationary gaussian fading channels with a peak power constraint"
    - "capacity of sparse multipath channels in the ultra wideband regime"
    - "low snr capacity of fading channels with peak and average power constraints"
    - "mutual information and minimum mean square error in gaussian channels"
    - "capacity per unit energy of fading channels with a peak constraint"

Connected through hyperedge HE-4 (induced by source paper "training over sparse multipath channels in the low snr regime"):
  with members:
    - "necessary and sufficient conditions for sparsity pattern recovery"
    - "spreading signals in the wideband limit"
    - "capacity of sparse multipath channels in the ultra wideband regime"
    - "mutual information and minimum mean square error in gaussian channels"

Connected through hyperedge HE-5 (induced by source paper "energy efficiency in the low snr regime under queueing constraints and channel uncertainty"):
  with members:
    - "the impact of qos constraints on the energy efficiency of fixed rate wireless transmissions"
    - "analysis of energy efficiency in fading channels under qos constraints"
    - "on the capacity and energy efficiency of training based transmissions over fading channels"
    - "capacity of sparse multipath channels in the ultra wideband regime"

Connected through hyperedge HE-6 (induced by source paper "mimo wireless communications under statistical queueing constraints"):
  with members:
    - "energy efficiency of fixed rate wireless transmissions under queueing constraints and channel uncertainty"
    - "the impact of qos constraints on the energy efficiency of fixed rate wireless transmissions"
    - "analysis of energy efficiency in fading channels under qos constraints"
    - "capacity of sparse multipath channels in the ultra wideband regime"

Connected through hyperedge HE-7 (induced by source paper "the impact of qos constraints on the energy efficiency of fixed rate wireless transmissions"):
  with members:
    - "analysis of energy efficiency in fading channels under qos constraints"
    - "on the capacity and energy efficiency of training based transmissions over fading channels"
    - "capacity of sparse multipath channels in the ultra wideband regime"

Connected through hyperedge HE-8 (induced by source paper "spreading signals in the wideband limit"):
  with members:
    - "capacity of underspread noncoherent wssus fading channels under peak signal constraints"
    - "capacity of sparse multipath channels in the ultra wideband regime"
    - "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)