MICROPROCESSOR-BASED WALSH-FOURIER SPECTRAL ANALYZER

A microprocessor-based Walsh-Fourier spectral analyzer is described. It includes the sampling of the incoming signal at 64 times the input signal frequency, using a special purpose frequency multiplier module (FMM), storing the digital data in a permuted sequence in the system memory under the control of a direct memory access (DMA) controller, and performing a fast Walsh-Hadamard transform (FWHT) of the permuted data sequence. The system uses a single board computer SBC80/10 in an Intel System 80/10 and a special purpose board which includes FMM, DMA, and A/D conversion circuits. Fourier coefficients are obtained via a Walsh to Fourier conversion algorithm; the total process is then faster than the Cooley-Tukey FFT algorithm for a data length of 64 or less. Copyright © 1979 by The Institute of Electrical and Electronics Engineers, Inc.