Issue No.04 - April (1976 vol.9)
R. Kitai , McMaster University
The spectrum of a frequency-limited periodic wave may be obtained rapidly by measuring its truncated Walsh spectrum, and then converting from Walsh spectrum to Fourier spectrum after the measurement. The conversion process consists of a matrix multiplication in which a measured Walsh spectrum vector, of dimension 2<sup>k</sup>, is multiplied by a 2<sup>k</sup>X 2<sup>k</sup>conversion matrix that is compensated for Walsh-spectrum truncation, to yield the corresponding Fourier spectrum vector. The microprocessor is well suited to this end; it is also useful in monitoring instrument panel switches and driving a display and print-out. This paper compares available microprocessors from the viewpoint of BCD processing?and concludes that the Fairchild PPS25 processor is the one best suited to meet the requirements.
R. Kitai, I. Renyi, F. Vajda, "Using a Microprocessor in a Walsh-Fourier Spectral Analyzer", Computer, vol.9, no. 4, pp. 27-32, April 1976, doi:10.1109/C-M.1976.218557