CMSISDSP
Version 1.9.0
CMSIS DSP Software Library

a[n]
and b[n]
, with lengths n1
and n2
respectively, are zero padded so that their lengths become N
, which is greater than or equal to (n1+n21)
and is a power of 4 as FFT implementation is radix4. The convolution of a[n]
and b[n]
is obtained by taking the FFT of the input signals, multiplying the Fourier transforms of the two signals, and taking the inverse FFT of the multiplied result. A[k] = FFT(a[n],N) B[k] = FFT(b[n],N) conv(a[n], b[n]) = IFFT(A[k] * B[k], N)where
A[k]
and B[k]
are the Npoint FFTs of the signals a[n]
and b[n]
respectively. The length of the convolved signal is (n1+n21)
.testInputA_f32
points to the first input sequence srcALen
length of the first input sequence testInputB_f32
points to the second input sequence srcBLen
length of the second input sequence outLen
length of convolution output sequence, (srcALen + srcBLen  1)
AxB
points to the output array where the product of individual FFTs of inputs is stored.