Complex-by-Real Multiplication [Complex Math Functions]

Functions
void	arm_cmplx_mult_real_f32 (float32_t *pSrcCmplx, float32_t *pSrcReal, float32_t *pCmplxDst, uint32_t numSamples)
void	arm_cmplx_mult_real_q31 (q31_t *pSrcCmplx, q31_t *pSrcReal, q31_t *pCmplxDst, uint32_t numSamples)
void	arm_cmplx_mult_real_q15 (q15_t *pSrcCmplx, q15_t *pSrcReal, q15_t *pCmplxDst, uint32_t numSamples)

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Detailed Description

Multiplies a complex vector by a real 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 while the real array has a total of numSamples real values.

The underlying algorithm is used:

      
 for(n=0; n<numSamples; n++) {      
     pCmplxDst[(2*n)+0] = pSrcCmplx[(2*n)+0] * pSrcReal[n];      
     pCmplxDst[(2*n)+1] = pSrcCmplx[(2*n)+1] * pSrcReal[n];      
 }      
 

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

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Function Documentation

void arm_cmplx_mult_real_f32	(	float32_t *	pSrcCmplx,
		float32_t *	pSrcReal,
		float32_t *	pCmplxDst,
		uint32_t	numSamples
	)

Floating-point complex-by-real multiplication.

Parameters:

[in]	*pSrcCmplx	points to the complex input vector
[in]	*pSrcReal	points to the real input vector
[out]	*pCmplxDst	points to the complex output vector
[in]	numSamples	number of samples in each vector

Returns:

none.

Definition at line 68 of file arm_cmplx_mult_real_f32.c.

void arm_cmplx_mult_real_q31	(	q31_t *	pSrcCmplx,
		q31_t *	pSrcReal,
		q31_t *	pCmplxDst,
		uint32_t	numSamples
	)

Q31 complex-by-real multiplication.

Parameters:

[in]	*pSrcCmplx	points to the complex input vector
[in]	*pSrcReal	points to the real input vector
[out]	*pCmplxDst	points to the complex output vector
[in]	numSamples	number of samples in each vector

Returns:

none.

Scaling and Overflow Behavior:

The function uses saturating arithmetic. Results outside of the allowable Q31 range[0x80000000 0x7FFFFFFF] will be saturated.

Definition at line 50 of file arm_cmplx_mult_real_q31.c.

void arm_cmplx_mult_real_q15	(	q15_t *	pSrcCmplx,
		q15_t *	pSrcReal,
		q15_t *	pCmplxDst,
		uint32_t	numSamples
	)

Q15 complex-by-real multiplication.

Parameters:

[in]	*pSrcCmplx	points to the complex input vector
[in]	*pSrcReal	points to the real input vector
[out]	*pCmplxDst	points to the complex output vector
[in]	numSamples	number of samples in each vector

Returns:

none.

Conditions for optimum performance

Input and output buffers should be aligned by 32-bit

Scaling and Overflow Behavior:

The function uses saturating arithmetic. Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.

Definition at line 54 of file arm_cmplx_mult_real_q15.c.