On Walsh-domain versus RDFT filtering
Okan K. Ersoy · IEEE Transactions on Acoustics Speech and Signal Processing · 1988
Spectral filtering and the computation of Fourier coefficients by the fast Walsh transform (FWT) and the fast algorithm for the real discrete Fourier transform (FRFT) are discussed on a comparative basis. In all cases discussed, the FRFT has fewer multiplications and additions. As the comparisons show, there is no good reason for using the Walsh-Fourier method in spectral filtering or for the generation of Fourier coefficients if the number of operations are the major criterion. However, the Walsh-Fourier method may still be useful if both the Walsh and the Fourier coefficients are to be utilized in a particular application.>