CMSIS-DSP  Version 1.4.4
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Complex Conjugate

Functions

void arm_cmplx_conj_f32 (float32_t *pSrc, float32_t *pDst, uint32_t numSamples)
 Floating-point complex conjugate.
 
void arm_cmplx_conj_q15 (q15_t *pSrc, q15_t *pDst, uint32_t numSamples)
 Q15 complex conjugate.
 
void arm_cmplx_conj_q31 (q31_t *pSrc, q31_t *pDst, uint32_t numSamples)
 Q31 complex conjugate.
 

Description

Conjugates 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 and the data in each array is stored in an interleaved fashion (real, imag, real, imag, ...). Each array has a total of 2*numSamples values. The underlying algorithm is used:

        
for(n=0; n<numSamples; n++) {        
    pDst[(2*n)+0)] = pSrc[(2*n)+0];     // real part        
    pDst[(2*n)+1)] = -pSrc[(2*n)+1];    // imag part        
}        

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

Function Documentation

void arm_cmplx_conj_f32 ( float32_t pSrc,
float32_t pDst,
uint32_t  numSamples 
)
Parameters
*pSrcpoints to the input vector
*pDstpoints to the output vector
numSamplesnumber of complex samples in each vector
Returns
none.
void arm_cmplx_conj_q15 ( q15_t pSrc,
q15_t pDst,
uint32_t  numSamples 
)
Parameters
*pSrcpoints to the input vector
*pDstpoints to the output vector
numSamplesnumber of complex samples in each vector
Returns
none.

Scaling and Overflow Behavior:

The function uses saturating arithmetic. The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.

References __SIMD32.

void arm_cmplx_conj_q31 ( q31_t pSrc,
q31_t pDst,
uint32_t  numSamples 
)
Parameters
*pSrcpoints to the input vector
*pDstpoints to the output vector
numSamplesnumber of complex samples in each vector
Returns
none.

Scaling and Overflow Behavior:

The function uses saturating arithmetic. The Q31 value -1 (0x80000000) will be saturated to the maximum allowable positive value 0x7FFFFFFF.