/*----------------------------------------------------------------------------- * Copyright (C) 2010-2013 ARM Limited. All rights reserved. * * $Date: 17. January 2013 * $Revision: V1.4.1 * * Project: CMSIS DSP Library * Title: arm_lms_norm_init_f32.c * * Description: Floating-point NLMS filter initialization function. * * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * - Neither the name of ARM LIMITED nor the names of its contributors * may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ---------------------------------------------------------------------------*/ #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 Description: * pCoeffs points to the array of filter coefficients stored in time reversed order: *
    
 *    {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}    
 * 
* The initial filter coefficients serve as a starting point for the adaptive filter. * pState points to an array of length numTaps+blockSize-1 samples, * where blockSize is the number of input samples processed by each call to arm_lms_norm_f32(). */ 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 */