Large-point one-dimensional FFT vectorization calculational method for GPDSP

Abstract

The invention discloses a large-point one-dimensional FFT vectorization calculational method for a GPDSP. When one-dimensional FFT with points of D=2<d> is calculated, calculation of d levels of FFT butterfly units is completed in two stages, wherein in the stage I, each level of FFT butterfly unit calculated through the first (d-m) levels of FFT butterfly units is completed through all vector processing array calculation units of DSP cores in a one-dimensional FFT butterfly unit calculation mode according to vectorization calculation till 2<m>-point sequence data can be completely stored in an in-chip sharing storage array of the GPDSP; in the stage II, all the vector processing array calculation units of the DSP cores carry out 2<d-m>-time 2<m>-point FFT calculation in sequence, a calculation method for transforming one dimension to two dimensions is adopted in vector processing arrays of the DSP cores, calculation is divided into FFT calculation with smaller points, and calculation is completed through the vector processing arrays of the DSP cores through a parallelization and vectorization calculation method. FFT calculation efficiency can be obviously improved, and data transmitting time cost can be lowered.

Description

technical field [0001] The present invention mainly relates to a general-purpose digital signal processor (General-Purpose Digital Signal Processor, referred to as GPDSP), in particular to a large-point one-dimensional FFT vectorization calculation method suitable for GPDSP. Background technique [0002] Discrete Fourier Transform (DFT) is widely used in the field of modern signal processing systems, such as radar signal processing, SAR image processing, sonar computing, video image algorithms, spectrum analysis, speech recognition, etc. Fourier transform calculation is a typical calculation-intensive and memory-intensive application. For example, the computational complexity of N-point DFT transform is o(N 2 ). In 1965, Cooley and Turkey proposed a fast Fourier transform (FFT) calculation method, which can significantly reduce the amount of calculation, and the calculation complexity is changed from the original o(N 2 ) down to o(Nlog 2 N). Signal processing application...

AI Technical Summary

Problems solved by technology

[0005] For the large-point FFT calculation oriented to GPDSP, because the capacity of the on-chip vector array memory of the DSP core is not large enough, the original sequence data that needs to be processed by FFT cannot be completely stored on the on-chip vector array memory of the DSP core, usually stored in the capacity Larger, but slower access to off-chip DDR memory

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