/* ----------------------------------------------------------------------
|
* Project: CMSIS DSP Library
|
* Title: arm_lms_init_q15.c
|
* Description: Q15 LMS filter initialization function
|
*
|
* $Date: 27. January 2017
|
* $Revision: V.1.5.1
|
*
|
* Target Processor: Cortex-M cores
|
* -------------------------------------------------------------------- */
|
/*
|
* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
|
*
|
* SPDX-License-Identifier: Apache-2.0
|
*
|
* Licensed under the Apache License, Version 2.0 (the License); you may
|
* not use this file except in compliance with the License.
|
* You may obtain a copy of the License at
|
*
|
* www.apache.org/licenses/LICENSE-2.0
|
*
|
* Unless required by applicable law or agreed to in writing, software
|
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
* See the License for the specific language governing permissions and
|
* limitations under the License.
|
*/
|
|
#include "arm_math.h"
|
|
/**
|
* @ingroup groupFilters
|
*/
|
|
/**
|
* @addtogroup LMS
|
* @{
|
*/
|
|
/**
|
* @brief Initialization function for the Q15 LMS filter.
|
* @param[in] *S points to an instance of the Q15 LMS filter structure.
|
* @param[in] numTaps number of filter coefficients.
|
* @param[in] *pCoeffs points to the coefficient buffer.
|
* @param[in] *pState points to the state buffer.
|
* @param[in] mu step size that controls filter coefficient updates.
|
* @param[in] blockSize number of samples to process.
|
* @param[in] postShift bit shift applied to coefficients.
|
* @return none.
|
*
|
* \par Description:
|
* <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
|
* <pre>
|
* {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
|
* </pre>
|
* The initial filter coefficients serve as a starting point for the adaptive filter.
|
* <code>pState</code> points to the array of state variables and size of array is
|
* <code>numTaps+blockSize-1</code> samples, where <code>blockSize</code> is the number of
|
* input samples processed by each call to <code>arm_lms_q15()</code>.
|
*/
|
|
void arm_lms_init_q15(
|
arm_lms_instance_q15 * S,
|
uint16_t numTaps,
|
q15_t * pCoeffs,
|
q15_t * pState,
|
q15_t mu,
|
uint32_t blockSize,
|
uint32_t postShift)
|
{
|
/* Assign filter taps */
|
S->numTaps = numTaps;
|
|
/* Assign coefficient pointer */
|
S->pCoeffs = pCoeffs;
|
|
/* Clear state buffer and size is always blockSize + numTaps - 1 */
|
memset(pState, 0, (numTaps + (blockSize - 1U)) * sizeof(q15_t));
|
|
/* Assign state pointer */
|
S->pState = pState;
|
|
/* Assign Step size value */
|
S->mu = mu;
|
|
/* Assign postShift value to be applied */
|
S->postShift = postShift;
|
|
}
|
|
/**
|
* @} end of LMS group
|
*/
|
