  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.
