On Walsh-domain versus RDFT filtering

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