Complex Magnitude SquaredComplex Math Functions

Functions

void arm_cmplx_mag_squared_f32 (float32_t *pSrc, float32_t *pDst, uint32_t numSamples)
 Floating-point complex magnitude squared.
 
void arm_cmplx_mag_squared_q15 (q15_t *pSrc, q15_t *pDst, uint32_t numSamples)
 Q15 complex magnitude squared.
 
void arm_cmplx_mag_squared_q31 (q31_t *pSrc, q31_t *pDst, uint32_t numSamples)
 Q31 complex magnitude squared.
 

Description

Computes the magnitude squared of the elements of a complex data vector.

The pSrc points to the source data and pDst points to the where the result should be written. numSamples specifies the number of complex samples in the input array and the data is stored in an interleaved fashion (real, imag, real, imag, ...). The input array has a total of 2*numSamples values; the output array has a total of numSamples values.

The underlying algorithm is used:

for(n=0; n<numSamples; n++) {
    pDst[n] = pSrc[(2*n)+0]^2 + pSrc[(2*n)+1]^2;
}

There are separate functions for floating-point, Q15, and Q31 data types.

Function Documentation

void arm_cmplx_mag_squared_f32 ( float32_t *  pSrc,
float32_t *  pDst,
uint32_t  numSamples 
)
Parameters
[in]*pSrcpoints to the complex input vector
[out]*pDstpoints to the real output vector
[in]numSamplesnumber of complex samples in the input vector
Returns
none.
void arm_cmplx_mag_squared_q15 ( q15_t *  pSrc,
q15_t *  pDst,
uint32_t  numSamples 
)
Parameters
*pSrcpoints to the complex input vector
*pDstpoints to the real output vector
numSamplesnumber of complex samples in the input vector
Returns
none.

Scaling and Overflow Behavior:

The function implements 1.15 by 1.15 multiplications and finally output is converted into 3.13 format.

References __SIMD32, and __SMUAD().

void arm_cmplx_mag_squared_q31 ( q31_t *  pSrc,
q31_t *  pDst,
uint32_t  numSamples 
)
Parameters
*pSrcpoints to the complex input vector
*pDstpoints to the real output vector
numSamplesnumber of complex samples in the input vector
Returns
none.

Scaling and Overflow Behavior:

The function implements 1.31 by 1.31 multiplications and finally output is converted into 3.29 format. Input down scaling is not required.