Eli Hughes / CMSIS_DSP_401

V4.0.1 of the ARM CMSIS DSP libraries. Note that arm_bitreversal2.s, arm_cfft_f32.c and arm_rfft_fast_f32.c had to be removed. arm_bitreversal2.s will not assemble with the online tools. So, the fast f32 FFT functions are not yet available. All the other FFT functions are available.

Dependents:   MPU9150_Example fir_f32 fir_f32 MPU9150_nucleo_noni2cdev ... more

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Complex Matrix Multiplication
Functions

Complex Matrix Multiplication
[Matrix Functions]

Complex Matrix multiplication is only defined if the number of columns of the first matrix equals the number of rows of the second matrix. More...

Functions

arm_status arm_mat_cmplx_mult_f32 (const arm_matrix_instance_f32 *pSrcA, const arm_matrix_instance_f32 *pSrcB, arm_matrix_instance_f32 *pDst)
 Floating-point Complex matrix multiplication.
arm_status arm_mat_cmplx_mult_q15 (const arm_matrix_instance_q15 *pSrcA, const arm_matrix_instance_q15 *pSrcB, arm_matrix_instance_q15 *pDst, q15_t *pScratch)
 Q15 Complex matrix multiplication.
arm_status arm_mat_cmplx_mult_q31 (const arm_matrix_instance_q31 *pSrcA, const arm_matrix_instance_q31 *pSrcB, arm_matrix_instance_q31 *pDst)
 Q31 Complex matrix multiplication.

Detailed Description

Complex Matrix multiplication is only defined if the number of columns of the first matrix equals the number of rows of the second matrix.

Multiplying an M x N matrix with an N x P matrix results in an M x P matrix. When matrix size checking is enabled, the functions check: (1) that the inner dimensions of pSrcA and pSrcB are equal; and (2) that the size of the output matrix equals the outer dimensions of pSrcA and pSrcB.

Function Documentation

arm_status arm_mat_cmplx_mult_f32 ( const arm_matrix_instance_f32 *  pSrcA,
const arm_matrix_instance_f32 *  pSrcB,
arm_matrix_instance_f32 *  pDst 
)

Floating-point Complex matrix multiplication.

Floating-point, complex, matrix multiplication.

Parameters:
[in]*pSrcApoints to the first input complex matrix structure
[in]*pSrcBpoints to the second input complex matrix structure
[out]*pDstpoints to output complex matrix structure
Returns:
The function returns either ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.

Definition at line 73 of file arm_mat_cmplx_mult_f32.c.

arm_status arm_mat_cmplx_mult_q15 ( const arm_matrix_instance_q15 *  pSrcA,
const arm_matrix_instance_q15 *  pSrcB,
arm_matrix_instance_q15 *  pDst,
q15_t *  pScratch 
)

Q15 Complex matrix multiplication.

Q15, complex, matrix multiplication.

Parameters:
[in]*pSrcApoints to the first input complex matrix structure
[in]*pSrcBpoints to the second input complex matrix structure
[out]*pDstpoints to output complex matrix structure
[in]*pScratchpoints to the array for storing intermediate results
Returns:
The function returns either ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.
Conditions for optimum performance
Input, output and state buffers should be aligned by 32-bit
Restrictions
If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE In this case input, output, scratch buffers should be aligned by 32-bit

Scaling and Overflow Behavior:

The function is implemented using a 64-bit internal accumulator. The inputs to the multiplications are in 1.15 format and multiplications yield a 2.30 result. The 2.30 intermediate results are accumulated in a 64-bit accumulator in 34.30 format. This approach provides 33 guard bits and there is no risk of overflow. The 34.30 result is then truncated to 34.15 format by discarding the low 15 bits and then saturated to 1.15 format.
Refer to arm_mat_mult_fast_q15() for a faster but less precise version of this function.

Definition at line 88 of file arm_mat_cmplx_mult_q15.c.

arm_status arm_mat_cmplx_mult_q31 ( const arm_matrix_instance_q31 *  pSrcA,
const arm_matrix_instance_q31 *  pSrcB,
arm_matrix_instance_q31 *  pDst 
)

Q31 Complex matrix multiplication.

Q31, complex, matrix multiplication.

Parameters:
[in]*pSrcApoints to the first input complex matrix structure
[in]*pSrcBpoints to the second input complex matrix structure
[out]*pDstpoints to output complex matrix structure
Returns:
The function returns either ARM_MATH_SIZE_MISMATCH or ARM_MATH_SUCCESS based on the outcome of size checking.

Scaling and Overflow Behavior:

The function is implemented using an internal 64-bit accumulator. The accumulator has a 2.62 format and maintains full precision of the intermediate multiplication results but provides only a single guard bit. There is no saturation on intermediate additions. Thus, if the accumulator overflows it wraps around and distorts the result. The input signals should be scaled down to avoid intermediate overflows. The input is thus scaled down by log2(numColsA) bits to avoid overflows, as a total of numColsA additions are performed internally. The 2.62 accumulator is right shifted by 31 bits and saturated to 1.31 format to yield the final result.

Definition at line 75 of file arm_mat_cmplx_mult_q31.c.

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