Low-Complexity Constant Multiplication Based on Trigonometric Identities with Applications to FFTs

SUMMARY In this work we consider optimized twiddle factor multipliers based on shift-and-add-multiplication. We propose a low-complexity structure for twiddle factors with a resolution of 32 points. Furthermore, we propose a slightly modified version of a previously reported multiplier for a resolution of 16 points with lower round-off noise. For completeness we also include results on optimal coefficients for eight points resolution. We perform finite word length analysis for both coefficients and round-off errors and derive optimized coefficients with a minimum complexity for varying requirements.