Upsampling technology-based fast Fourier transform/inverse fast Fourier transform (FFT/IFFT) approximate calculation method and device

Abstract

The invention discloses an upsampling technology-based fast Fourier transform / inverse fast Fourier transform (FFT / IFFT) approximate calculation method and an upsampling technology-based FFT / IFFT approximate calculation device. The method comprises the following steps of: determining the number of small sampling points and the multiple of an upsampling filter according to the number of actual valid data sampling points and the number of large FFT / IFFT output sampling points; performing zero padding on the actual valid data sampling points until the number of the sampling points reaches the number of the small sampling points, and performing cyclic shift and FFT / IFFT on a small sampling point sequence obtained through zero padding to obtain an FFT / IFFT output result of the small sampling points; and performing zero insertion on the FFT / IFFT output result of the small sampling points until the number of the sampling points reaches the number of the large FFT / IFFT output sampling points, and performing upsampling filtering on a large sampling point sequence obtained through zero insertion. By the method and the device for realizing the FFT / IFFT of the large sampling points through the FFT / IFFT of the small sampling points and the upsampling filter, the problems of large calculated amount and high resource consumption when a system processes the FFT / IFFT process of the large sampling points are solved.

Description

technical field [0001] The invention relates to FFT / IFFT technology in the field of communication technology, in particular to an FFT / IFFT approximate calculation method and device based on upsampling technology. Background technique [0002] FFT / IFFT is a fast algorithm of discrete Fourier transform DFT / inverse discrete Fourier transform IDFT, which is widely used in signal processing, communication systems and other fields, especially in communication systems such as LTE / CMMB / WIFI using OFDM technology. [0003] Assuming that x(n) is a finite-length sequence of N points, its DFT / IFFT operation expression is shown in formula (1), where W N 1 = e - j 2 π N , [0004] X ( ...

AI Technical Summary

Problems solved by technology

[0010] The purpose of the present invention is to provide a FFT / IFFT approximate calculation method based on upsampling technology, which is used to solve the problem of large amount of calculation and resource consumption in the process of processing large sample point FFT / IFFT in the system

[0011] Another object of the present invention is to provide a FFT / IFFT approximate calculation device based on upsampling technology, which is used to solve the problem of large amount of computation and resource consumption in the process of processing large-sample FFT / IFFT in the system

Images