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: "physical network coding in two way wireless relay channels"
  Abstract: It has recently been recognized that the wireless networks represent a fertile ground for devising communication modes based on network coding. A particularly suitable application of the network coding arises for the two--way relay channels, where two nodes communicate with each other assisted by using a third, relay node. Such a scenario enables application of \emph{physical network coding}, where the network coding is either done (a) jointly with the channel coding or (b) through physical combining of the communication flows over the multiple access channel. In this paper we first group the existing schemes for physical network coding into two generic schemes, termed 3--step and 2--step scheme, respectively. We investigate the conditions for maximization of the two--way rate for each individual scheme: (1) the Decode--and--Forward (DF) 3--step schemes (2) three different schemes with two steps: Amplify--and--Forward (AF), JDF and Denoise--and--Forward (DNF). While the DNF scheme has a potential to offer the best two--way rate, the most interesting result of the paper is that, for some SNR configurations of the source--relay links, JDF yields identical maximal two--way rate as the upper bound on the rate for DNF.

Connected through hyperedge HE-1 (induced by source paper "coherent detection for short packet physical layer network coding with fsk modulation"):
  with members:
    - "noncoherent detection for physical layer network coding"
    - "practical power balanced non orthogonal multiple access"
    - "ultra reliable short packet communications half duplex or full duplex relaying"
    - "complex linear physical layer network coding"
    - "mobile lattice coded physical layer network coding with practical channel alignment"
    - "on the subtleties of q pam linear physical layer network coding"
    - "reliable physical layer network coding supporting real applications"
    - "ultra reliable communication in 5g wireless systems"

Connected through hyperedge HE-2 (induced by source paper "deep learning based constellation optimization for physical network coding in two way relay networks"):
  with members:
    - "end to end deep learning of optical fiber communications"
    - "channel agnostic end to end learning based communication systems with conditional gan"
    - "end to end learning of communications systems without a channel model"
    - "deep learning for joint source channel coding of text"
    - "an introduction to deep learning for the physical layer"
    - "adam a method for stochastic optimization"
    - "physical layer network coding tutorial survey and beyond"
    - "channel coding and decoding in a relay system operated with physical layer network coding"

Connected through hyperedge HE-3 (induced by source paper "noncoherent detection for physical layer network coding"):
  with members:
    - "asynchronous physical layer network coding symbol misalignment estimation and its effect on decoding"
    - "on the subtleties of q pam linear physical layer network coding"
    - "network coded multiple access with high order modulations"
    - "asynchronous physical layer network coding"
    - "physical layer network coding tutorial survey and beyond"
    - "compute and forward harnessing interference through structured codes"

Connected through hyperedge HE-4 (induced by source paper "simultaneous wireless information and power transfer in cooperative relay networks with rateless codes"):
  with members:
    - "optimum transmission policies for energy harvesting sensor networks powered by a mobile control center"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "enhancing wireless information and power transfer by exploiting multi antenna techniques"
    - "wireless information and energy transfer for two hop non regenerative mimo ofdm relay networks"
    - "outage analysis and optimization for time switching based two way relaying with energy harvesting relay node"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "application of smart antenna technologies in simultaneous wireless information and power transfer"

Connected through hyperedge HE-5 (induced by source paper "physical layer network coding a random coding error exponent perspective"):
  with members:
    - "code design for short blocks a survey"
    - "towards massive ultra reliable and low latency wireless the art of sending short packets"
    - "asynchronous physical layer network coding with quasi cyclic codes"
    - "mismatched decoding error exponents second order rates and saddlepoint approximations"
    - "asynchronous physical layer network coding"
    - "physical layer network coding tutorial survey and beyond"
    - "channel coding and decoding in a relay system operated with physical layer network coding"

Connected through hyperedge HE-6 (induced by source paper "energy efficient resource allocation for hybrid bursty services in multi relay ofdm networks"):
  with members:
    - "spectral and energy spectral efficiency optimization of joint transmit and receive beamforming based multi relay mimo ofdma cellular networks"
    - "achieving maximum energy efficiency in multi relay ofdma cellular networks a fractional programming approach"
    - "relay selection with network coding in two way relay channels"

Connected through hyperedge HE-7 (induced by source paper "sign compute resolve for tree splitting random access"):
  with members:
    - "identifying randomly activated users via sign compute resolve on graphs"
    - "coded random access applying codes on graphs to design random access protocols"
    - "many access channels the gaussian case with random user activities"
    - "sign compute resolve for random access"
    - "coded splitting tree protocols"
    - "random access with physical layer network coding"
    - "reliable physical layer network coding"
    - "physical layer network coding tutorial survey and beyond"

Connected through hyperedge HE-8 (induced by source paper "decoupled uplink and downlink in a wireless system with buffer aided relaying"):
  with members:
    - "why to decouple the uplink and downlink in cellular networks and how to do it"
    - "achievable rates for the fading half duplex single relay selection network using buffer aided relaying"
    - "analysis of the decoupled access for downlink and uplink in wireless heterogeneous networks"
    - "joint rate and sinr coverage analysis for decoupled uplink downlink biased cell associations in hetnets"
    - "downlink and uplink decoupling a disruptive architectural design for 5g networks"
    - "load backhaul aware decoupled downlink uplink access in 5g systems"
    - "buffer aided relaying with adaptive link selection"
    - "five disruptive technology directions for 5g"

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)