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: "On the effect of correlated fading on several space-time coding and detection schemes"
  Abstract: Antenna spacings, the angle spread and the Rice factor significantly affect the correlation of fading coefficients in a multi-antenna system. We study the effect of these parameters on the performance of different types of detection schemes in a BLAST architecture. We show that the detection method based on lattice decoding is more resistant to the correlated fading than other types of detection which are based on successive interference cancellation. We notice that highly correlated fades significantly degrade the performance of detection techniques based on successive interference cancellation whereas they slightly affect the lattice decoding algorithm. We also study the effects of correlated fades on some space-time block codes. We show that space-time block codes from orthogonal design are more resistant to correlation than other high rate linear space-time block codes.

Connected through hyperedge HE-1 (induced by source paper "Space-time correlation modeling of multielement antenna systems in mobile fading channels"):
  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: Mathematics