Digital Walsh-Fourier spectral conversion for periodic waves

Relationships are presented that allow the determination of Fourier coefficients of frequency-band-limited periodic waves from a truncated spectrum of sequency-aliased Walsh coefficients. The sequency-aliasing compensation matrix takes a simple form when the number of data sample-points is 2/sup (p+1)/, where p is a positive integer. For such a case the compensation matrix is a diagonal matrix which premultiplies the converted Fourier coefficients. The sequency-aliasing compensation matrix is combined with Kitai's matrix (1975, 1978); Kitai's matrix compensates for truncation of the Walsh series. Kitai's compensation matrix, which premultiplies Fourier coefficients following conversion into the Fourier domain, takes its simplest form if the highest sequency to be converted is 2/sup p/-1; for this situation, a close relationship exists between the elements of Kitai's compensation matrix and the sequency-aliasing compensation matrix. >