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/* ----------------------------------------------------------------------
* Project: CMSIS DSP Library
* Title: arm_lms_norm_init_f32.c
* Description: Floating-point NLMS filter initialization function
*
* $Date: 18. March 2019
* $Revision: V1.6.0
*
* Target Processor: Cortex-M cores
* -------------------------------------------------------------------- */
/*
* Copyright (C) 2010-2019 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_NORM
@{
*/
/**
@brief Initialization function for floating-point normalized LMS filter.
@param[in] S points to an instance of the floating-point LMS filter structure
@param[in] numTaps number of filter coefficients
@param[in] pCoeffs points to coefficient buffer
@param[in] pState points to state buffer
@param[in] mu step size that controls filter coefficient updates
@param[in] blockSize number of samples to process
@return none
@par Details
<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 an array of length <code>numTaps+blockSize-1</code> samples,
where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_lms_norm_f32()</code>.
*/
void arm_lms_norm_init_f32(
arm_lms_norm_instance_f32 * S,
uint16_t numTaps,
float32_t * pCoeffs,
float32_t * pState,
float32_t mu,
uint32_t blockSize)
{
/* 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(float32_t));
/* Assign state pointer */
S->pState = pState;
/* Assign Step size value */
S->mu = mu;
/* Initialise Energy to zero */
S->energy = 0.0f;
/* Initialise x0 to zero */
S->x0 = 0.0f;
}
/**
@} end of LMS_NORM group
*/
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