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: "exploiting interference alignment in multi cell cooperative ofdma resource allocation"
  Abstract: This paper studies interference alignment (IA) based multi-cell cooperative resource allocation for the downlink OFDMA with universal frequency reuse. Unlike the traditional scheme that treats subcarriers as separate dimensions for resource allocation, the IA technique is utilized to enable frequency-domain precoding over parallel subcarriers. In this paper, the joint optimization of frequency-domain precoding via IA, subcarrier user selection and power allocation is investigated for a cooperative three-cell OFDMA system to maximize the downlink throughput. Numerical results for a simplified symmetric channel setup reveal that the IA-based scheme achieves notable throughput gains over the traditional scheme only when the inter-cell interference link has a comparable strength as the direct link, and the receiver SNR is sufficiently large. Motivated by this observation, a practical hybrid scheme is proposed for cellular systems with heterogenous channel conditions, where the total spectrum is divided into two subbands, over which the IAbased scheme and the traditional scheme are applied for resource allocation to users located in the cell-intersection region and cellnon- intersection region, respectively. It is shown that this hybrid resource allocation scheme flexibly exploits the downlink IA gains for OFDMA-based cellular systems.

Connected through hyperedge HE-1 (induced by source paper "role of interference alignment in wireless cellular network optimization"):
  with members:
    - "joint beamforming and power control in coordinated multicell max min duality effective network and large system transition"
    - "multilevel topological interference management"
    - "on the feasibility of linear interference alignment for mimo interference broadcast channels with constant coefficients"
    - "genie chain and degrees of freedom of symmetric mimo interference broadcast channels"
    - "degrees of freedom of mimo cellular networks decomposition and linear beamforming design"
    - "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"
    - "degrees of freedom of mimo x networks spatial scale invariance one sided decomposability and linear feasibility"

Connected through hyperedge HE-2 (induced by source paper "distributed energy spectral efficiency optimization for partial full interference alignment in multi user multi relay multi cell mimo systems"):
  with members:
    - "limited feedback based interference alignment for interfering multi access channels"
    - "performance analysis and optimization for interference alignment over mimo interference channels with limited feedback"
    - "opportunistic downlink interference alignment"
    - "spectral and energy spectral efficiency optimization of joint transmit and receive beamforming based multi relay mimo ofdma cellular networks"
    - "maximizing energy efficiency in multi relay ofdma cellular networks"
    - "achieving maximum energy efficiency in multi relay ofdma cellular networks a fractional programming approach"
    - "a reconfigurable distributed algorithm for k user mimo interference networks"
    - "framework for link level energy efficiency optimization with informed transmitter"

Connected through hyperedge HE-3 (induced by source paper "cognitive orthogonal precoder for two tiered networks deployment"):
  with members:
    - "optimal channel training in uplink network mimo systems"
    - "interference alignment for the k user mimo interference channel"
    - "from spectrum pooling to space pooling opportunistic interference alignment in mimo cognitive networks"
    - "adaptive limited feedback for sum rate maximizing beamforming in cooperative multicell systems"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "vandermonde frequency division multiplexing for cognitive radio"
    - "femtocell networks a survey"

Connected through hyperedge HE-4 (induced by source paper "improving macrocell small cell coexistence through adaptive interference draining"):
  with members:
    - "a distributed approach to interference alignment in ofdm based two tiered networks"
    - "enhanced intercell interference coordination challenges in heterogeneous networks"
    - "contract based cooperative spectrum sharing"
    - "cooperative algorithms for mimo interference channels"
    - "on feasibility of interference alignment in mimo interference networks"
    - "downlink interference alignment"
    - "performance of interference alignment in clustered wireless ad hoc networks"
    - "from spectrum pooling to space pooling opportunistic interference alignment in mimo cognitive networks"

Connected through hyperedge HE-5 (induced by source paper "interference mitigation techniques for clustered multicell joint decoding systems"):
  with members:
    - "free probability based capacity calculation of multiantenna gaussian fading channels with cochannel interference"
    - "interference alignment with limited feedback on two cell interfering two user mimo mac"
    - "on feasibility of interference alignment in mimo interference networks"
    - "on feasibility of interference alignment in mimo interference networks"
    - "on the achievability of interference alignment in the k user constant mimo interference channel"
    - "approaching the capacity of wireless networks through distributed interference alignment"
    - "gaussian interference channel capacity to within one bit"

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)