  Quantum Fourier Transform (QFT) plays a principal role in the development of
efficient quantum algorithms. Since the number of quantum bits that can
currently built is limited, while many quantum technologies are inherently
three- (or more) valued, we consider extending the reach of the realistic
quantum systems by building a QFT over ternary quantum digits. Compared to
traditional binary QFT, the q-valued transform improves approximation
properties and increases the state space by a factor of (q/2)n. Further, we use
non-binary QFT derivation to generalize and improve the approximation bounds
for QFT.
