Spread-Spectrum Based on Finite Field Fourier Transforms.

Spread-spectrum systems are presented, which are based on Finite Field Fourier Transforms. Orthogonal spreading sequences defined over a finite field are derived. New digital multiplex schemes based on such spread-spectrum systems are also introduced, which are multilevel Coding Division Multiplex. These schemes termed Galois-field Division Multiplex (GDM) offer compact bandwidth requirements because only leaders of cyclotomic cosets are needed to be transmitted.