Real FFT Tables

Variables
const float32_t	realCoefA [8192]
const float32_t	realCoefB [8192]
const q31_t	realCoefAQ31 [8192]
const q31_t	realCoefBQ31 [8192]
const q15_t	realCoefAQ15 [8192]
const q15_t	realCoefBQ15 [8192]

Description

Variable Documentation

realCoefA

const float32_t realCoefA[8192]

Generation of realCoefA array:

n = 4096

for (i = 0; i < n; i++)
{
   pATable[2 * i]     = 0.5 * ( 1.0 - sin (2 * PI / (double) (2 * n) * (double) i));
   pATable[2 * i + 1] = 0.5 * (-1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}

realCoefAQ15

const q15_t realCoefAQ15[8192]

Generation fixed-point realCoefAQ15 array in Q15 format:

n = 4096

for (i = 0; i < n; i++)
{
   pATable[2 * i]     = 0.5 * ( 1.0 - sin (2 * PI / (double) (2 * n) * (double) i));
   pATable[2 * i + 1] = 0.5 * (-1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}

Convert to fixed point Q15 format round(pATable[i] * pow(2, 15))

realCoefAQ31

const q31_t realCoefAQ31[8192]

Generation fixed-point realCoefAQ31 array in Q31 format:

n = 4096

for (i = 0; i < n; i++)
{
   pATable[2 * i]     = 0.5 * ( 1.0 - sin (2 * PI / (double) (2 * n) * (double) i));
   pATable[2 * i + 1] = 0.5 * (-1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}

Convert to fixed point Q31 format round(pATable[i] * pow(2, 31))

realCoefB

const float32_t realCoefB[8192]

Generation of realCoefB array:

n = 4096

for (i = 0; i < n; i++)
{
   pBTable[2 * i]     = 0.5 * (1.0 + sin (2 * PI / (double) (2 * n) * (double) i));
   pBTable[2 * i + 1] = 0.5 * (1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}

realCoefBQ15

const q15_t realCoefBQ15[8192]

Generation of real_CoefB array:

n = 4096

for (i = 0; i < n; i++)
{
   pBTable[2 * i]     = 0.5 * (1.0 + sin (2 * PI / (double) (2 * n) * (double) i));
   pBTable[2 * i + 1] = 0.5 * (1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
}

Convert to fixed point Q15 format round(pBTable[i] * pow(2, 15))

realCoefBQ31

const q31_t realCoefBQ31[8192]

Generation of realCoefBQ31 array:

n = 4096

for (i = 0; i < n; i++)
{
   pBTable[2 * i]     = 0.5 * (1.0 + sin (2 * PI / (double) (2 * n) * (double) i));
   pBTable[2 * i + 1] = 0.5 * (1.0 * cos (2 * PI / (double) (2 * n) * (double) i));
} 

Convert to fixed point Q31 format round(pBTable[i] * pow(2, 31))