human: Given a node-centered hypergraph: <hypergraph>, where nodes represent authors and hyperedges represent groups of authors who co-authored the same paper.

Details of the hypergraph:
Center node: "Combined Pulse Shape and Pulse Position Modulation for High Data Rate Transmissions in Ultra-Wideband Communications"
  Abstract: In this paper we present a novel method for high data rate transmissions in ultra-wideband (UWB) communications systems. This is achieved through the combination of conventional pulse position modulation and pulse shape modulation schemes. The result is a pulse shape and position modulation that allows transmission of more bits of information in the same amount of time and using the same number of pulses as the conventional schemes. A feature of the proposed system is that the allowable alphabet is limited so as to ensure equal power in transmission of all symbols. Symbol size can also be easily changed without significantly changing the hardware of the system. Theoretical error performance analysis of this system is also provided.

Connected through hyperedge HE-1 (induced by source paper "On the design of orthogonal pulse-shape modulation for UWB systems using Hermite pulses"):
  with members:
    (none)

Question: Please tell me which research area the center author belongs to. The 4 classes are: Computer science, Mathematics, Engineering, Economics, Psychology, Business. Directly output the class name.

gpt: Computer science