1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_nuttall3b_f64.c
4 * Description: Floating-point (f64) Nuttall3b window
5 *
6 * $Date: 14 December 2022
7 * $Revision: v1.15.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2022 ARM Limited or its affiliates. All rights reserved.
13 *
14 * SPDX-License-Identifier: Apache-2.0
15 *
16 * Licensed under the Apache License, Version 2.0 (the License); you may
17 * not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
19 *
20 * www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28
29 #include "dsp/window_functions.h"
30 #include "dsp/fast_math_functions.h"
31 #include <math.h>
32
33 /**
34 @ingroup groupWindow
35 */
36
37
38
39
40 /**
41 @addtogroup WindowNormal
42 @{
43 */
44
45
46 /**
47 @ingroup WindowNUTTALL3B
48 */
49
50 /**
51 @brief Nuttall3b window generating function (f64).
52 @param[out] pDst points to the output generated window
53 @param[in] blockSize number of samples in the window
54 @return none
55
56 @par Parameters of the window
57
58 | Parameter | Value |
59 | ------------------------------------: | -----------------: |
60 | Peak sidelobe level | 71.5 dB |
61 | Normalized equivalent noise bandwidth | 1.7037 bins |
62 | 3 dB bandwidth | 1.6162 bins |
63 | Flatness | -1.1352 dB |
64 | Recommended overlap | 59.8 % |
65
66 */
67
68
69
arm_nuttall3b_f64(float64_t * pDst,uint32_t blockSize)70 void arm_nuttall3b_f64(
71 float64_t * pDst,
72 uint32_t blockSize)
73 {
74 float64_t k = 2. / ((float64_t) blockSize);
75 float64_t w;
76
77 for(uint32_t i=0;i<blockSize;i++)
78 {
79 w = PI_F64 * i * k;
80 w = 0.4243801 - 0.4973406 * cos (w) + 0.0782793 * cos (2 * w);
81
82 pDst[i] = w;
83 }
84 }
85
86 /**
87 @} end of WindowNormal group
88 */
89
90