US 2010/0150365 A1 · SIGNAL PROCESSING DEVICE, ECHO CANCELLER, AND SIGNAL PROCESSING METHOD

Abstract

If K=4N, wherein K is a number of subbands and N is a decimation ratio, an analysis filter process unit 21 is used to perform an analysis filter process for every N samples of real-valued input data and output K samples of real-valued data. A GDFT/SSB modulation batch process unit (81) performs a GDFT process and an SSB modulation process on the outputted data by using a real-valued matrix calculation using a (K/2)×K real-valued matrix to output 1 sample×(K/2) channel of real-valued subbands data. Moreover, an SSB demodulation/inverse GDFT batch process unit (82) performs an SSB demodulation process and an inverse GDFT process on 1 sample×(K/2) channel of real-valued subbands data by a real-valued matrix calculation using a K×(K/2) real-valued matrix and outputs K samples of real-valued data. The outputted data is subjected to a synthesis filter process by a synthesis filter process unit (24) to output N samples of real-valued data.

Claims11

Dependent claims

A signal processing device performing a subband analysis process on an input signal, characterized by comprising:

analysis filter process means for performing an analysis filter process on every N samples of real-valued input data and outputting K samples of real-valued data if K=4N, where K is the number of subbands and N is a decimation ratio;
and
GDFT/SSB modulation batch process means for performing a GDFT process, which is a Generalized Discrete Fourier Transformation process, and an SSB modulation process, which is a single sideband modulation process, by a product arithmetic in batch between a (K/2)×K real-valued matrix and a K×1 real-valued matrix, on the K samples of real-valued data inputted from the analysis filter process means, and outputting 1 sample×(K/2) channel of real-valued subbands data.

A signal processing device performing a subband analysis process on an input signal, characterized by comprising:

analysis filter process means for performing an analysis filter process on every N samples of real-valued input data and outputting K samples of real-valued data if K=4N, where K is the number of subbands and N is a decimation ratio;
and
GDFT/SSB modulation batch process means for performing in batch a GDFT process, which is a Generalized Discrete Fourier Transformation process where a frequency offset is ½ and a time offset is n0, and an SSB modulation process, which is a single sideband modulation process, using (K/2)×K real-valued matrix G1(m) represented in an equation
[
Expression
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G
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and according to an equation
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on K samples of real-valued data, xm(0), xm(1), . . . , xm(k−1), outputted from the analysis filter process means provided that time index of the K samples of real-valued data from the analysis filter process means is m, and outputting 1 sample×(K/2) channel of real-valued subbands data, X0SSB(m), X1SSB(m), . . . , XK/2−1SSB(m).

351 more elements

A signal processing device performing subband synthesis process on an input signal, characterized by comprising:

SSB demodulation/inverse GDFT batch process means for performing in batch an SSB demodulation process, which is a single sideband demodulation process, and an inverse GDFT process, which is an inverse Generalized Discrete Fourier Transformation process where a frequency offset is ½ and a time offset is n0, using a K×(K/2) real-valued matrix G2(m) represented in an equation
[
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=
0
,
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and according to an equation
[
x
m
′
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(
0
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x
m
′
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1
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x
m
′
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=
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2
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0
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m
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]
on every input of 1 sample×(K/2) channel of real-valued subbands data, X′0SSB(m), X′1SSB(m), . . . , X′K/2−1SSB(m) provided that a time index of the real-valued subbands data is m and outputting K samples of real-valued data, x′m(0), x′m(1), . . . , x′m(k−1), if K=4N, where K is the number of subbands and N is a decimation ratio;
and
synthesis filter process means for performing a synthesis filter process on the K samples of real-valued data inputted from the SSB demodulation/inverse GDFT batch process means and outputting N samples of real-valued data.

361 more elements

A signal processing device performing a subband analysis process on an input signal, characterized by comprising:

analysis filter process means for performing an analysis filter process on every N samples of real-valued input data and outputting K samples of real-valued data if K=4N, where K is the number of subbands and N is a decimation ratio;
GDFT/SSB modulation batch process means for performing a GDFT process, which is a Generalized Discrete Fourier Transformation process, and an SSB modulation process, which is a single sideband modulation process, by a (K/2)×K real-valued matrix arithmetic in batch, on the real-valued data of K samples inputted from the analysis filter process means, and outputting 1 sample×(K/2) channel of real-valued subbands data;
SSB demodulation/inverse GDFT batch process means for performing an SSB demodulation process, which is a single sideband demodulation process, and an inverse GDFT process, which is an inverse Generalized Discrete Fourier Transformation process, by a K×(K/2) real-valued matrix arithmetic in batch on every input of 1 sample×(K/2) channel of real-valued subbands data, and outputting K samples of real-valued data;
and
synthesis filter process means for performing a synthesis filter process on the K samples of real-valued data inputted from the SSB demodulation/inverse GDFT batch process means and outputting N samples of real-valued data.

2 more elements

A signal processing method performing a subband analysis process and a subband synthesis process on an input signal, characterized by comprising:

a first step of outputting K samples of real-valued data by performing an analysis filter process on every N samples of real-valued input data if K=4N, where K is the number of subbands and N is a decimation ratio;
a second step of outputting 1 sample×(K/2) channel of real-valued subbands data, X0SSB(m), X1SSB(m), . . . , XK/2−1SSB(m) by performing a GDFT process, which is a Generalized Discrete Fourier Transformation process where a frequency offset is ½ and a time offset is n0, and an SSB modulation process, which is a single sideband modulation process, using (K/2)×K real-valued matrix G1(m) represented in an equation
[
Expression
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G
1
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=
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and according to an equation
[
X
0
SSB
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(
m
)
X
1
SSB
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(
m
)
…
X
K
/
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-
1
SSB
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(
m
)
]
=
G
1

(
m
)

[
x
m

(
0
)
x
m

(
1
)
…
x
m
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-
1
)
]
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m
=
0
,
1
,
…
[
Expression
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6
]
on K samples of real-valued data, xm(0), xm(1), xm(k−1), that time index of K samples of real-valued data from the first step is m;
a third step of outputting 1 sample×(K/2) channel of real-valued subbands data by performing a signal process on every subbands of K/2 channel on 1 sample×(K/2) channel of real-valued subbands data from the second step;
a fourth step of outputting K samples of real-valued data, x′m(0), x′m(1), x′m(k−1), by performing in batch an SSB demodulation process, which is a single sideband demodulation process, and an inverse GDFT process, which is an inverse Generalized Discrete Fourier Transformation process, using a K×(K/2) real-valued matrix G2(m) represented in an equation
[
Expression
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
7
]
G
2
(
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m
)
=
[
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cos

[
2
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π
2

K
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{
(
n
0
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)
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cos
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[
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K
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{
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0
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Km
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…
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cos
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cos
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π
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K
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…
cos

[
2
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π
2

K
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{
(
K
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(
n
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4
}
]
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]
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
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m
=
0
,
1
,
…
and according to an equation
[
x
m
′

(
0
)
x
m
′
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(
1
)
…
x
m
′
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(
K
-
1
)
]
=
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2
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(
m
)

[
X
0
′

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SSB
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(
m
)
X
1
′
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m
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…
X
K
/
2
-
1
′
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(
m
)
]
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m
=
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,
1
,
…
[
Expression
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
8
]
on every inputs of real-valued subbands data, X′0SSB(m), X′1SSB(m), . . . , X′K/2−1SSB(m), that time index of the 1 sample×(K/2) channel of real-valued data from the third step is m;
and
a fifth step of outputting N samples of real-valued data by performing a synthesis filter process on K samples of real-valued data outputted from the fourth step.

717 more elements

Dependencies are inferred from the claim text.

Signal processing device, echo canceller, and signal processing method

Life of this patent

Signal processing device, echo canceller, and signal processing method

Life of this patent

Abstract

Claims11