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CMSIS DSP library

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Complex-by-Complex Multiplication
Functions

Complex-by-Complex Multiplication
[Complex Math Functions]

Multiplies a complex vector by another complex vector and generates a complex result. More...

Functions

void arm_cmplx_mult_cmplx_f32 (float32_t *pSrcA, float32_t *pSrcB, float32_t *pDst, uint32_t numSamples)
 Floating-point complex-by-complex multiplication.
void arm_cmplx_mult_cmplx_q15 (q15_t *pSrcA, q15_t *pSrcB, q15_t *pDst, uint32_t numSamples)
 Q15 complex-by-complex multiplication.
void arm_cmplx_mult_cmplx_q31 (q31_t *pSrcA, q31_t *pSrcB, q31_t *pDst, uint32_t numSamples)
 Q31 complex-by-complex multiplication.

Detailed Description

Multiplies a complex vector by another complex vector and generates a complex result.

The data in the complex arrays is stored in an interleaved fashion (real, imag, real, imag, ...). The parameter numSamples represents the number of complex samples processed. The complex arrays have a total of 2*numSamples real values.

The underlying algorithm is used:

        
 for(n=0; n<numSamples; n++) {        
     pDst[(2*n)+0] = pSrcA[(2*n)+0] * pSrcB[(2*n)+0] - pSrcA[(2*n)+1] * pSrcB[(2*n)+1];        
     pDst[(2*n)+1] = pSrcA[(2*n)+0] * pSrcB[(2*n)+1] + pSrcA[(2*n)+1] * pSrcB[(2*n)+0];        
 }

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

Function Documentation

void arm_cmplx_mult_cmplx_f32 ( float32_t *  pSrcA,
float32_t *  pSrcB,
float32_t *  pDst,
uint32_t  numSamples 
)

Floating-point complex-by-complex multiplication.

Parameters:
[in]*pSrcApoints to the first input vector
[in]*pSrcBpoints to the second input vector
[out]*pDstpoints to the output vector
[in]numSamplesnumber of complex samples in each vector
Returns:
none.

Definition at line 83 of file arm_cmplx_mult_cmplx_f32.c.

void arm_cmplx_mult_cmplx_q15 ( q15_t *  pSrcA,
q15_t *  pSrcB,
q15_t *  pDst,
uint32_t  numSamples 
)

Q15 complex-by-complex multiplication.

Parameters:
[in]*pSrcApoints to the first input vector
[in]*pSrcBpoints to the second input vector
[out]*pDstpoints to the output vector
[in]numSamplesnumber of complex samples in each 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.

Definition at line 65 of file arm_cmplx_mult_cmplx_q15.c.

void arm_cmplx_mult_cmplx_q31 ( q31_t *  pSrcA,
q31_t *  pSrcB,
q31_t *  pDst,
uint32_t  numSamples 
)

Q31 complex-by-complex multiplication.

Parameters:
[in]*pSrcApoints to the first input vector
[in]*pSrcBpoints to the second input vector
[out]*pDstpoints to the output vector
[in]numSamplesnumber of complex samples in each 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.

Definition at line 67 of file arm_cmplx_mult_cmplx_q31.c.

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