mlib_SignalNLMSFilterFree_F32_F32(3mlib)

1mlib_SignalNLMSFilter(3MLIBm)ediaLib Library Functionmslib_SignalNLMSFilter(3MLIB)
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NAME

6       mlib_SignalNLMSFilter,   mlib_SignalNLMSFilterInit_S16_S16,   mlib_Sig‐
7       nalNLMSFilterInit_S16S_S16S,         mlib_SignalNLMSFilterInit_F32_F32,
8       mlib_SignalNLMSFilterInit_F32S_F32S, mlib_SignalNLMSFilter_S16_S16_Sat,
9       mlib_SignalNLMSFilter_S16S_S16S_Sat,     mlib_SignalNLMSFilter_F32_F32,
10       mlib_SignalNLMSFilter_F32S_F32S,              mlib_SignalNLMSFilterNon‐
11       Adapt_S16_S16_Sat,         mlib_SignalNLMSFilterNonAdapt_S16S_S16S_Sat,
12       mlib_SignalNLMSFilterNonAdapt_F32_F32,        mlib_SignalNLMSFilterNon‐
13       Adapt_F32S_F32S, mlib_SignalNLMSFilterFree_S16_S16, mlib_SignalNLMSFil‐
14       terFree_S16S_S16S,  mlib_SignalNLMSFilterFree_F32_F32, mlib_SignalNLMS‐
15       FilterFree_F32S_F32S - normalized least  mean  square  (NLMS)  adaptive
16       filtering
17

SYNOPSIS

19       cc [ flag... ] file... -lmlib [ library... ]
20       #include <mlib.h>
21
22       mlib_status mlib_SignalNLMSFilterInit_S16_S16(void **filter,
23            const mlib_f32 *flt, mlib_s32 tap, mlib_f32 beta);
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26       mlib_status mlib_SignalNLMSFilterInit_S16S_S16S(void **filter,
27            const mlib_f32 *flt, mlib_s32 tap, mlib_f32 beta);
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30       mlib_status mlib_SignalNLMSFilterInit_F32_F32(void **filter,
31            const mlib_f32 *flt, mlib_s32 tap, mlib_f32 beta);
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34       mlib_status mlib_SignalNLMSFilterInit_F32S_F32S(void **filter,
35            const mlib_f32 *flt, mlib_s32 tap, mlib_f32 beta);
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38       mlib_status mlib_SignalNLMSFilter_S16_S16_Sat(mlib_s16 *dst,
39            const mlib_s16 *src, const mlib_s16 *ref, void *filter, mlib_s32 n);
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42       mlib_status mlib_SignalNLMSFilter_S16S_S16S_Sat(mlib_s16 *dst,
43            const mlib_s16 *src, const mlib_s16 *ref, void *filter, mlib_s32 n);
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46       mlib_status mlib_SignalNLMSFilter_F32_F32(mlib_f32 *dst,
47            const mlib_f32 *src, const mlib_f32 *ref, void *filter, mlib_s32 n);
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50       mlib_status mlib_SignalNLMSFilter_F32S_F32S(mlib_f32 *dst,
51            const mlib_f32 *src, const mlib_f32 *ref, void *filter, mlib_s32 n);
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54       mlib_status mlib_SignalNLMSFilterNonAdapt_S16_S16_Sat(mlib_s16 *dst,
55            const mlib_s16 *src, const mlib_s16 *ref, void *filter, mlib_s32 n);
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58       mlib_status mlib_SignalNLMSFilterNonAdapt_S16S_S16S_Sat(mlib_s16 *dst,
59            const mlib_s16 *src, const mlib_s16 *ref, void *filter, mlib_s32 n);
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61
62       mlib_status mlib_SignalNLMSFilterNonAdapt_F32_F32(mlib_f32 *dst,
63            const mlib_f32 *src, const mlib_f32 *ref, void *filter, mlib_s32 n);
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66       mlib_status mlib_SignalNLMSFilterNonAdapt_F32S_F32S(mlib_f32 *dst,
67            const mlib_f32 *src, const mlib_f32 *ref, void *filter, mlib_s32 n);
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70       void mlib_SignalNLMSFilterFree_S16_S16(void *filter);
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73       void mlib_SignalNLMSFilterFree_S16S_S16S(void *filter);
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76       void mlib_SignalNLMSFilterFree_F32_F32(void *filter);
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79       void mlib_SignalNLMSFilterFree_F32S_F32S(void *filter);
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DESCRIPTION

83       The normalized LMS adaptive algorithm is summarized as follows:
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85           1.     Initialize the weights Wk(i), i = 0, 1, ..., tap - 1.
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87           2.     Initialize  previous  source  elements Xo(i), i = 0, 1, ...,
88                  tap - 1.
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90           3.     Read Xk(t) from src and Yk(t) from ref, t = 0, 1, ...,  n  -
91                  1.
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93           4.     Compute  filter  output: nk = sum(Wk(i) * Xk(t - i)), i = 0,
94                  1, ..., tap - 1. If i >  t,  use  previous  source  elements
95                  stored in the Xo vector.
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97           5.     Compute  source elements power: Pwk = sum(Xk(t - i) * Xk(t -
98                  i)), i = 0, 1, ..., tap - 1. If i > t, use  previous  source
99                  elements stored in the Xo vector.
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101           6.     Store filter output : dst[t] = nk.
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103           7.     Compute the error estimate: Ek = Yk - nk.
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105           8.     Compute factor BE0 = 2 * beta * Ek / Pwk.
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107           9.     Update  filter  weights: Wk(i) += BE0 * Xk(t - i), i = 0, 1,
108                  ..., tap - 1. If i > t, use previous source elements  stored
109                  in the Xo vector.
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111           10.    Next t, go to step 3.
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113           11.    Store  N  ending source elements in previous source elements
114                  vector Xo: if N > n, N = n; else N = tap.
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117       Each of the FilterInit functions allocates memory for the internal fil‐
118       ter structure and converts the parameters into the internal representa‐
119       tion.
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122       Each of the Filter functions applies the NLMS adaptive  filter  on  one
123       signal packet and updates the filter states.
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126       Each of the FilterNoAdapt functions applies the NLMS filter on one sig‐
127       nal packet and updates the filter states but without changing the  fil‐
128       ter weights.
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131       Each  of the FilterFree functions releases the memory allocated for the
132       internal filter structure.
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PARAMETERS

135       Each of the functions takes some of the following arguments:
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137       filter    Internal filter structure.
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140       flt       Filter coefficient array.
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143       tap       Taps of the filter.
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146       beta      Error weighting factor. 0 < beta < 1.
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149       dst       Destination signal array.
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152       src       Source signal array.
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155       ref       Reference or "desired" signal array.
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158       n         Number of samples in the source signal array.
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RETURN VALUES

162       Each of the FilterInit, Filter  and  FilterNonAdapt  functions  returns
163       MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE. The Fil‐
164       terFree functions don't return anything.
165

ATTRIBUTES

167       See attributes(5) for descriptions of the following attributes:
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172       ┌─────────────────────────────┬─────────────────────────────┐
173       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
174       ├─────────────────────────────┼─────────────────────────────┤
175       │Interface Stability          │Committed                    │
176       ├─────────────────────────────┼─────────────────────────────┤
177       │MT-Level                     │MT-Safe                      │
178       └─────────────────────────────┴─────────────────────────────┘
179

NAME

SYNOPSIS

DESCRIPTION

PARAMETERS

RETURN VALUES

ATTRIBUTES

SEE ALSO