Abstract
The vector rotation operation in the butterfly of a Fast Fourier Transform (FFT) can be calculated by a complex multiplier as well as a CORDIC (COordinate Rotation DIgital Computer). For these vector rotation blocks, expressions for the maximum numerical error are derived. It is shown that the error introduced by the CORDIC can be reduced by increasing the size of the input vector of the CORDIC and decreasing the size of the output vector by the same amount. This input vector scaling makes the reduction possible of the number of bits in the data path of the CORDIC. The impact on the Signal to Noise Ratio (SNR) of the FFT is evaluated when a CORDIC is applied in the FFT butterfly.
Similar content being viewed by others
References
J.W. Cooley and J.W. Tukey, “An Algorithm for the Machine Calculation of Complex Fourier Series,” Math. Computation, vol. 19, 1965, pp. 297–301.
A.M. Despain, “Fourier Transform Computers Using CORDIC Iterations,” IEEE Transactions on Computers, vol. C-23, 1974, pp. 993–1001.
K. Nowak, R. Nouta, M. Bekooij, and E. Deprettere, “An Efficient Implementation of a 256-point FFT Processor with CORDIC for OFDM Systems,” Proc. ProRISC, 1998.
J.E. Volder, “The CORDIC Trigonimetric Computing Technique,” IRE Transactions on Electronic Computers, vol. EC-8, 1959, pp. 330–334.
G.J. Hekstra, “CORDIC for High Performance Numerical Computation,” Ph.D. Thesis, TU-Delft, 1998.
S. Mitra, Digital Signal Processing, McGRAW-HILL, 1998.
Y.H. Hu, “The Quantization Effects of the CORDIC Algorithm,” IEEE Signal Processing, vol. 40, 1992, pp. 834–844.
K. Kota and J. Cavallaro, “Numerical Accuracy and Hardware Tradeoffs for CORDIC Arithmetic for Special-Purpose Processors,” IEEE Transactions on Computers, vol. 42, 1993, pp. 769–779.
B.L. Floch, R. Halbert-Lassalle, and D. Castelain, “Digital Sound Broadcasting to Mobile Receivers,” IEEE Transactions on Consumer Electronics, vol. 35, 1989.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bekooij, M., Huisken, J. & Nowak, K. Numerical Accuracy of Fast Fourier Transforms with CORDIC Arithmetic. The Journal of VLSI Signal Processing-Systems for Signal, Image, and Video Technology 25, 187–193 (2000). https://doi.org/10.1023/A:1008179225059
Published:
Issue Date:
DOI: https://doi.org/10.1023/A:1008179225059