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: "sum rate maximized resource allocation in multiple df relays aided ofdm transmission"
  Abstract: In relay-aided wireless transmission systems, one of the key issues is how to decide assisting relays and manage the energy resource at the source and each individual relay, to maximize a certain objective related to system performance. This paper addresses the sum rate maximized resource allocation (RA) problem in a point to point orthogonal frequency division modulation (OFDM) transmission system assisted by multiple decode-and-forward (DF) relays, subject to the individual sum power constraints of the source and the relays. In particular, the transmission at each subcarrier can be in either the direct mode without any relay assisting, or the relay-aided mode with one or several relays assisting. We propose two RA algorithms which optimize the assignment of transmission mode and source power for every subcarrier, as well as the assisting relays and the power allocation to them for every {relay-aided} subcarrier. First, it is shown that the considered RA problem has zero Lagrangian duality gap when there is a big number of subcarriers. In this case, a duality based algorithm that finds a globally optimum RA is developed. Second, a coordinate-ascent based iterative algorithm, which finds a suboptimum RA but is always applicable regardless of the duality gap of the RA problem, is developed. The effectiveness of these algorithms has been illustrated by numerical experiments.

Connected through hyperedge HE-1 (induced by source paper "resource allocation for secure gaussian parallel relay channels with finite length coding and discrete constellations"):
  with members:
    - "enhancing physical layer security in af relay assisted multicarrier wireless transmission enhancing physical layer security in af relay assisted multicarrier wireless transmission"
    - "joint relay selection and power allocation in large scale mimo systems with untrusted relays and passive eavesdroppers"
    - "secrecy optimized resource allocation for device to device communication underlaying heterogeneous networks"
    - "optimal power allocation by imperfect hardware analysis in untrusted relaying networks"
    - "secure communication over parallel relay channel"
    - "secure and reliable transmission with cooperative relays in two hop wireless networks"
    - "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input"
    - "on cooperative relaying schemes for wireless physical layer security"

Connected through hyperedge HE-2 (induced by source paper "power allocation for adaptive ofdm index modulation in cooperative networks"):
  with members:
    - "index modulation techniques for 5g wireless networks"
    - "multiple input multiple output ofdm with index modulation"

Connected through hyperedge HE-3 (induced by source paper "simultaneous wireless information and power transfer for two hop ofdm relay system"):
  with members:
    - "simultaneous information and power transfer for broadband wireless systems"
    - "wireless information and power transfer in multiuser ofdm systems"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "wireless information and power transfer architecture design and rate energy tradeoff"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-4 (induced by source paper "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"):
  with members:
    - "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"
    - "on the scale algorithm for multiuser multicarrier power spectrum management"
    - "wsr maximized resource allocation in multiple df relays aided ofdma downlink transmission"
    - "joint subcarrier pairing and power allocation for ofdm transmission with decode and forward relaying"
    - "optimization framework and graph based approach for relay assisted bidirectional ofdma cellular networks"

Connected through hyperedge HE-5 (induced by source paper "novel subcarrier pair based opportunistic df protocol for cooperative downlink ofdma"):
  with members:
    - "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"
    - "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"
    - "wsr maximized resource allocation in multiple df relays aided ofdma downlink transmission"
    - "joint subcarrier pairing and power allocation for ofdm transmission with decode and forward relaying"

Connected through hyperedge HE-6 (induced by source paper "on the optimum energy efficiency for flat fading channels with rate dependent circuit power"):
  with members:
    - "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"
    - "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"
    - "framework for link level energy efficiency optimization with informed transmitter"

Connected through hyperedge HE-7 (induced by source paper "power minimization for ofdm transmission with subcarrier pair based opportunistic df relaying"):
  with members:
    - "weighted sum rate maximization for downlink ofdma with subcarrier pair based opportunistic df relaying"
    - "wsr maximized resource allocation in multiple df relays aided ofdma downlink transmission"

Connected through hyperedge HE-8 (induced by source paper "on the scale algorithm for multiuser multicarrier power spectrum management"):
  with members:
    - "wsr maximized resource allocation in multiple df relays aided ofdma downlink transmission"

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)