Low-complexity rotators for the FFT using base-3 signed stages

Rotations by angles that are fractions of the unit circle find applications in e.g. fast Fourier transform (FFT) architectures. In this work we propose a new rotator that consists of a series of stages. Each stage calculates a micro-rotation by an angle corresponding to a power-of-three fractional parts. Using a continuous powers-of-three range, it is possible to carry out all rotations required. In addition, the proposed rotators are compared to previous approaches, based of shift-and-add algorithms, showing improvements in accuracy and number of adders.