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Library
Description
The FFT block computes the fast Fourier transform (FFT) of each channel in the M-by-N input matrix, u
.
y = fft(u,M) % Equivalent MATLAB code
For both sample-based and frame-based inputs, the block assumes that each input column is a frame containing M consecutive samples from an independent channel. The frame size, M, must be a power of two. To work with other frame sizes, use the Zero Pad block to pad or truncate the frame size to a power-of-two length.
The output is a complex M-by-N matrix whose lth column contains the discrete Fourier transform (DFT) of the corresponding input column at M evenly spaced frequency points in the range [0,Fs), where Fs is the input sample rate, Fs = 1/Ts Hz.
The output is always sample-based, and the output port rate is the same as the input port rate.
For convenience, length-M 1-D vector inputs and sample-based length-M row vector inputs are processed as single channels (i.e., as M-by-1 column vectors), and the output has the same dimension as the input.
Dialog Box
See Also
Complex Cepstrum |
DSP Blockset |
DCT |
DSP Blockset |
IFFT |
DSP Blockset |
Zero Pad |
DSP Blockset |
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