Complex-by-Real Multiplication

Functions
void	arm_cmplx_mult_real_f16 (const float16_t *pSrcCmplx, const float16_t *pSrcReal, float16_t *pCmplxDst, uint32_t numSamples)
	Floating-point complex-by-real multiplication.
void	arm_cmplx_mult_real_f32 (const float32_t *pSrcCmplx, const float32_t *pSrcReal, float32_t *pCmplxDst, uint32_t numSamples)
	Floating-point complex-by-real multiplication.
void	arm_cmplx_mult_real_q15 (const q15_t *pSrcCmplx, const q15_t *pSrcReal, q15_t *pCmplxDst, uint32_t numSamples)
	Q15 complex-by-real multiplication.
void	arm_cmplx_mult_real_q31 (const q31_t *pSrcCmplx, const q31_t *pSrcReal, q31_t *pCmplxDst, uint32_t numSamples)
	Q31 complex-by-real multiplication.

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.

Function Documentation

arm_cmplx_mult_real_f16()

void arm_cmplx_mult_real_f16	(	const float16_t *	pSrcCmplx,
		const float16_t *	pSrcReal,
		float16_t *	pCmplxDst,
		uint32_t	numSamples
	)

Floating-point complex-by-real multiplication.

Parameters

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

arm_cmplx_mult_real_f32()

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

Floating-point complex-by-real multiplication.

Parameters

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

arm_cmplx_mult_real_q15()

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

Q15 complex-by-real multiplication.

Parameters

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

Scaling and Overflow Behavior

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

arm_cmplx_mult_real_q31()

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

Q31 complex-by-real multiplication.

Parameters

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

Scaling and Overflow Behavior

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