Three-dimensional FFT calculation device based on FPGA

Abstract

The invention discloses a three-dimensional FFT calculation device based on an FPGA. The three-dimensional FFT calculation device mainly solves the problem that in the prior art, FFT calculation cannot be conducted on large-size three-dimensional data, wherein the FPGA comprises a one-dimensional FFT calculator, a two-dimensional FFT calculator, a data buffer area and an external memory, the databuffer area is formed by using an internal block RAM of the FPGA, and the external memory caches a result calculated by the two-dimensional FFT calculator; the three-dimensional FFT calculator calculates the FFT of the third dimension data according to the calculation result of the two-dimensional FFT cached by the external memory to obtain a three-dimensional FFT calculation result; and the datatransmission control module generates address information to control an intermediate result obtained by calculating the two-dimensional FFT to be cached to an external memory through an AXI4 bus, andcontrols the FPGA to read data from the external memory according to a page sequence. The method is high in calculation precision, the calculated three-dimensional FFT result meets the actual requirement, and the method can be used for simulating dynamic sea surface electromagnetic scattering.

Description

technical field [0001] The invention belongs to the technical field of digital signal processing, and in particular relates to a three-dimensional FFT calculation device, which can be used for simulating the change of echoes in X and Y directions in space and in three dimensions of time T during electromagnetic scattering on a dynamic sea surface. Background technique [0002] When using the statistical model to simulate the electromagnetic scattering of the dynamic sea surface, it is necessary to consider the echo changes in the X and Y directions in space and the three dimensions of time T. As the size of the sea surface to be simulated becomes larger, the method of summing directly according to the formula takes a long time and cannot quickly calculate the result. But by virtue of the formula's similarity to the discrete Fourier transform formula format, fast Fourier transform algorithms can be used to speed up calculations. [0003] Discrete Fourier transform is of grea...

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Problems solved by technology

[0007] The counting key of realizing the object of the present invention is the limited situation of storing resources inside the FPGA, using an external memory to solve the problem of insufficient internal resources of the FPGA due to the large amount of cached data, to calculate the data of three dimensions, the device includes a one-dimensional The FFT calculator, the two-dimensional FFT calculator with internal data buffer and the data buffer using FPGA internal block RAM are characterized in that it also includes:

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