1)  IFFT

2)  fast fourier transform (FFT)

1.
Then the fast Fourier transform (FFT) is adopted to calculate the Fourier coefficients of the fundamental.

2.
The Fast Fourier Transform (FFT), developed originally by Cooley and Tukey , is one of the Discrete Fourier Transform (DFT) algorithms .

3)  FFT

1.
A CGFFT algorithm for transformation from the near-field to the aperture-field;

2.
The N = 2￣M FFT Algorithm for Decimation in Time;

3.
PRECISE LASER WAVELENGTH DETERMINED BY FFT;

4)  fast Fourier transform

1.
The Fast Fourier Transform Identifies the Frequency Responses of Mathematical Models in Discrete Time Domain;

2.
The numerical simulation of diffraction based on fast Fourier transform;

3.
The Realization of Fast Fourier Transform Based on FPGA in Laser Spectrum Detection;

5)  fast Fourier transforms

1.
The near field coupling can be computed by the traditional method of moments(MoM);while the impedance elements of far field coupling are characterized as a Toeplitz matrix by interpolating Green\'s function on a regular Cartesian grid,and the matrix-vector products are accelerated by fast Fourier transforms.

6)  Fast Fourier Transform(FFT)

1.
Sampling theory conditions in fast Fourier transform(FFT) to calculate Collins formula are discussed.

2.
The fast analysis method to deal with the large scale experiment data of the real ship in wave,including the valid data sampling,the data centering adjustment,the Fast Fourier Transform(FFT) and the statistics of the amplitude,has been researched.

3.
It tests the speed of NVIDIA CUBLAS,CUDA kernel,common C program,Intel MKL BLAS,CUDA driver API program,FFTW and CUFFT Library in matrix-multiplication and Fast Fourier Transform(FFT).

 快速傅里叶变换fast Fourier trans formation   进行有限离散傅里叶变换(DFT)的快速算法。简称FFT。一个复杂的波形可以分解为一系列谐波。针对这一物理现象，在数学上建立并发展了一套有效的研究方法，这就是傅里叶分析。利用电子计算机进行傅里叶分析，主要处理离散函数的傅里叶展开，也就是三角函数的插值问题。一维DFT所作的工作主要是把一个N元数组A（i）（i＝0，1，…，N－1）通过一种线性变换变成另一个N元数组X（i）（i＝0，…N，-1）。如果直接计算全部数组元素大约需要进行 N2次的乘法和加法运算，当N很大时其计算量是很惊人的。1965年美国人库利和图基提出一种能大幅度减少运算次数的快速算法，即FFT算法，它的基本原理是将一个变换分解为两个变换的乘积，并利用三角函数的周期性质，将原先的变换公式重新组合为新的公式，从而把运算次数减少到Nlog2N的量级。这就是说，FFT算法比DFT算法提高工效N／log2N倍，例如N＝220时，约提高5万倍速度，可见当N很大时，这是一个了不起的提高。FFT技术在谱分析、数字滤波、结构分析、系统分析、图像与信号处理，以及物探、天线、雷达、卫星、医疗等众多技术领域已获得成功的应用。