Applications of SIMD computers in signal processing

This paper analyzes in detail how far the proposed Single Instruction Multiple Data (SIMD) computers with interconnection networks are applicable in the signal processing area. Decimation in the time radix-2 fast Fourier transform (FFT) algorithm is considered here for implementation in a multiprocessor system with shared bus and an SIMD computer with interconnection network. Results are derived for data allocation, interprocessor communication, approximate computation time, speedup, and cost effectiveness for an N-point FFT with any P available processors. Further generalization is obtained for a radix-r FFT algorithm. N X N point, two-dimensional discrete Fourier transform (DFT) implementation is also considered, with one or more rows of input matrix allocated to each processor. Various curves are plotted and a comparison in performance is carried out between a shared-bus multiprocessor and SIMD computer with interconnection network. It is shown that the latter gives much higher speedup for P > 16 and is more cost-effective even with the high cost of switches. N, P and r, considered here, are all powers of 2.