Ex Parte Nowlin et al

Board of Patent Appeals and Interferences

Mar 16, 2009

10645360 (B.P.A.I. Mar. 16, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
________________

Ex parte ROBERT WINSTON NOWLIN
and SETH SUPPAPPOLA
________________

Appeal 2009-0846
Application 10/645,360
Technology Center 2600
________________

Decided:1 March 16, 2009
________________

Before KENNETH W. HAIRSTON, MARC S. HOFF,
and KARL D. EASTHOM, Administrative Patent Judges.

HAIRSTON, Administrative Patent Judge.

DECISION ON APPEAL

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).

Appeal 2009-0846
Application 10/645,360

2
STATEMENT OF THE CASE
Appellants seek our review under 35 U.S.C. § 134 from the
Examiner’s final rejection of claims 1 to 10. We have jurisdiction under 35
U.S.C. § 6(b).
We reverse.

The Invention
Appellants’ invention is directed to a cellular telephone and a method
for providing a comfort noise signal in the telephone, the telephone having a
plurality of sub-band filters, the method including generating a white noise
signal and using a QMF filter bank to control the magnitude of white noise
in each QMF filter according to the sub-band filtered signal.2
Claim 1 is representative of the claims on appeal, and read as follows:
1. A method for providing a comfort noise signal in a telephone having a
receive channel and a transmit channel and a plurality of sub-band filters in
at least one channel, said method comprising the steps of:
generating a white noise signal;
applying the white noise signal to a QMF filter bank to produce a
comfort noise signal, wherein the magnitude of the white noise into each
QMF filter is controlled in accordance with the magnitude of the signal in a
corresponding sub-band in the one channel; and
selectively coupling the comfort noise signal to at least one of the
channels. (Emphasis added).

2 See generally Abstract; Spec. 2; Figs. 3-5; claims 1 and 6.
Appeal 2009-0846
Application 10/645,360

3
The Applied Prior Art
The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Swaminathan US 5,630,016 May 13, 1997
Uchino US 2003/0063662 A1 Apr. 3, 2003

The Rejection
The Examiner rejected claims 1 to 10 under 35 U.S.C. § 103(a) as
being unpatentable based on the teachings and suggestions of Swaminathan
and Uchino.

ISSUE
Appellants’ independent claims 1 and 6 each recite the feature of
using a QMF filter bank to filter plural sub-band filtered signals in order to
produce a comfort noise signal (hereinafter, “the QMF feature”) (see infra
Finding of Fact 2). Dependent claims 2 to 5 depend from claim 1, and
dependent claims 7 to 10 depend from claim 6. Thus, each of claims 1 to 10
on appeal recites the noted QMF feature.
The Examiner rejected claims 1 to 10 over the combination of
Swaminathan and Uchino. The Examiner relied upon Swaminathan as
showing the basic features of a digital cellular telephone including a comfort
noise generator, and relied upon Uchino as teaching (i) a white noise
generator, and (ii) a quadrature mirror filter (QMF) bank for filtering
multiple frequency sub-bands filtered by multiple sub-band filters where the
magnitude of white noise in each QMF is controlled according to the
magnitude of the signal in each sub-band (Ans. 3-6).
Appeal 2009-0846
Application 10/645,360

4
With regard to the QMF feature of claims 1 to 10 (see generally claim
1, emphasized portion, supra), the Examiner states:
… it would be obvious to one of ordinary skill in the art at the
time of the applicant[s’][sic] invention to apply Uchino et al.’s
method of generating noise in the telephone of Swaninathan et
al. in order to generate a noise signal that fluctuates along the
power spectrum density distribution characteristic of the
frequency fluctuations of the receive or transmit channel.

(Ans. 4 and 6, citing para. 0478 of Uchino) (emphasis added).
Appellants contend that Swaminathan and Uchino are unrelated and
that there is no basis for making the combination (Br. 4 and 7). Appellants
assert that the references are unrelated because Uchino is directed to testing
using a white noise signal, while Swaminathan and Appellants’ inventions
are directed to digital cellular telephones with comfort noise generators (Br.
4-6).
Accordingly, the issue is: Have Appellants established that the
Examiner has not presented a rational basis for combining the digital
communication system of Swaminathan with the test signal method and
apparatus of Uchino?
Rather than repeat the arguments of Appellants or the Examiner, we
refer to the Brief and the Answer for their respective details.3

3 We refer to the Appeal Brief (Br.) filed June 4, 2007, and the Examiner’s
Answer (Ans.) mailed September 10, 2007, throughout this opinion.

Appeal 2009-0846
Application 10/645,360

5
FINDINGS OF FACT
The findings of fact (FF) throughout this decision are supported by a
preponderance of the evidence of record. The following facts are pertinent
to the issue before us.
Appellants’ Disclosure
1. Appellants describe and claim a digital cellular telephone 22 (Fig. 3
and 4) and a method for providing a comfort noise signal in the telephone
22, the telephone 22 having plural sub-band filters 54 (Abstract). The
method includes generating a white noise signal and using a QMF filter bank
77 (see Fig. 6) to control the magnitude of white noise in each QMF filter
90-99 (see Fig. 8) according to the sub-band filtered signal (see generally
Spec. 2; Figs. 3-8; claim 1).
2. Independent claims 1 and 6 each recite the common limitation of
using a QMF filter bank to filter plural sub-band filtered signals in order to
produce a comfort noise signal (see claims 1 and 6).
3. Appellants disclose that there is a need in the art to use comfort
noise in a telephone or other voice communications device to suppress
residual echo, while at the same time generate an improved comfort noise
that matches actual background noise and has a more natural sound (i.e.,
avoids apparent loudness changes during conversation) (Spec. 1-2).
4. Appellants’ invention produces comfort noise which “more closely
matches the spectral content of actual noise during a call,” and does this “by
shaping white noise in a M channel quadrature mirror filter bank in
accordance with the amplitude of the actual noise” (Spec. 10).

Appeal 2009-0846
Application 10/645,360

6
Uchino
5. Uchino discloses a method and apparatus 20 for generating a test
signal to test the response of a digital line 1 (Fig. 1, 5, 22-24 and 26-28).
The test signal is generated with a wander generator 21 based on a random
number signal and a clock signal, and is combined with a white noise signal
n1-n13 and then filtered by a QMF filter bank 56/57 (Abs.; Fig. 1; para.
0472). Uchino teaches dividing the signal into plural sub-bands in order to
perform weighted processing on the signal, and then filtering the signal
using the QMF filter bank in accordance with weighting coefficients which
determine the spectrum characteristic of the output signal (paras. 0478 and
0490). The weighting coefficients are fixed and are set by the “characteristic
information setting means” (para. 0457). The weighting coefficients are set
according to testing parameters such as time interval error which accounts
for wander and jitter at certain frequencies (paras. 0007, 0008-0014, 0019,
and 0025-0027).
6. Uchino fails to teach testing a line during a phone call, during
cellular phone operation, or in any type of communication where there is a
variable signal such as voice, speech, or conversation. Uchino also fails to
teach using a QMF filter bank to process a voice signal in a cellular digital
telephone such that the amplitude of white noise is varied in accordance with
the amplitude of a variable (i.e., speech) signal.
Swaminathan
7. Swaminathan teaches a digital cellular telephone system (Figs. 1
and 2) and a method for providing a comfort noise signal in the telephone
using a comfort noise generator 76 (Abs.; col. 1, ll. 14-19). Swaminathan’s
comfort noise generator 76 operates to generate a comfort noise which is
Appeal 2009-0846
Application 10/645,360

7
based on a spectrally flattened background noise (see Fig. 3; col. 5, l. 30 to
col. 6, l. 11). Although Swaminathan discloses using an infinite impulse
response filter to filter the generated noise, and normalizing delayed samples
over time, there is no disclosure of dividing an input signal into plural sub-
bands for different processing based on input signal amplitude (see col. 3, ll.
41-64). The weighting factors (“a” and “1-a”) are not based on frequency
bands (col. 3, l. 66 to col. 4, l. 7). Likewise there is no teaching in
Swaminathan of using a QMF filter bank to process the spectrally flat
background noise signal.

PRINCIPLES OF LAW
"In rejecting claims under 35 U.S.C. § 103, the examiner bears the
initial burden of presenting a prima facie case of obviousness." In re
Rijckaert, 9 F.3d 1531, 1532 (Fed. Cir. 1993) (citing In re Oetiker, 977 F.2d
1443, 1445 (Fed. Cir. 1992)).
"'A prima facie case of obviousness is established when the teachings
from the prior art itself would appear to have suggested the claimed subject
matter to a person of ordinary skill in the art.'" In re Bell, 991 F.2d 781, 783
(Fed. Cir. 1993) (quoting In re Rinehart, 531 F.2d 1048, 1051 (CCPA
1976)).
“Section 103 forbids issuance of a patent when ‘the differences
between the subject matter sought to be patented and the prior art are such
that the subject matter as a whole would have been obvious at the time the
invention was made to a person having ordinary skill in the art to which said
subject matter pertains.’” KSR Int'l Co. v. Teleflex Inc., 127 S. Ct. 1727,
1734 (2007) (citation omitted). The Examiner’s “articulated reasoning . . .
Appeal 2009-0846
Application 10/645,360

8
in the rejection must possess a rational underpinning to support the legal
conclusion of obviousness.” In re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006).
The Supreme Court, citing Kahn, 441 F.3d at 988, stated that “rejections on
obviousness grounds cannot be sustained by mere conclusory statements;
instead, there must be some articulated reasoning with some rational
underpinning to support the legal conclusion of obviousness.” KSR, 127 S.
Ct. at 1741.
When combining references to show non-obviousness under § 103,
the Examiner must satisfy a two-prong test for analogous art, as set forth by
the Federal Circuit in In re Kahn, 441 F.3d 977:
The analogous-art test requires that the Board
show that a reference is either [1] in the field of the
applicant’s endeavor or [2] is reasonably pertinent
to the problem with which the inventor was
concerned in order to rely on that reference as a
basis for rejection. References are selected as
being reasonably pertinent to the problem based on
the judgment of a person having ordinary skill in
the art.
Kahn, 441 F.3d at 986-87 (emphasis added) (internal citations omitted).
Appellants have the burden on appeal to the Board to demonstrate an
error in the Examiner's position. See Kahn, 441 F.3d at 985-86.

ANALYSIS
Appellants’ argument that Uchino is unrelated to the method and
apparatus claimed, and thus is non-analogous art (Br. 6), is convincing. The
Appeal 2009-0846
Application 10/645,360

9
two-step test for determining whether a reference is analogous art (set forth
in Kahn, supra) is not met.
We agree with Appellants that (1) Uchino is directed to generating a
test signal (and is thus unrelated to Appellants’ claimed invention) (Br. 5-6),
and (2) that Uchino is not reasonably pertinent to the problem faced by
Appellants of providing comfort noise in a digital cellular telephone
environment while matching actual background noise, the same problem
with which Swaminathan was concerned (see generally Br. 7-8). Kahn, 441
F.3d at 986-87.
Step One of the Two-Step Test
The first step of the two-step test for analogous art set forth in Kahn
requires that the subject reference (i.e., Uchino) be from the same field of
endeavor as Appellants’ invention. Kahn, 441 F.3d at 986-87.
Appellants’ Specification and Swaminathan both disclose digital
cellular telephone systems (FF 1 and 7). Appellants’ Specification is
concerned with generating comfort noise in a digital cellular telephone
environment, and more specifically with matching comfort noise to the
actual background noise in order to add a little noise during conversation to
avoid changes in apparent loudness of speech during a call while making the
comfort noise sound more natural (Spec. 1-2). Swaminathan is concerned
with generating comfort noise in a digital cellular telephone environment
(FF 7), and also is concerned with producing comfort noise that more closely
matches the background noise in the call (FF 7). To the contrary, Uchino
relates to the testing of a digital line (not during a call) by using a wander
generator to generate white noise to test line response in a short measuring
Appeal 2009-0846
Application 10/645,360

10
time (e.g., phase noise, wander, jitter, etc.) (paras. 0002, 0003, and 0006; FF
5).
Although the Examiner is correct that Uchino and Swaminathan are
both broadly directed to digital communications systems (Ans. 5 and 8), the
systems of Appellants’ invention and Swaminathan (digital cellular
telephone communications system that generate a more natural sounding
comfort noise), are divergent from the system of Uchino which generates
and filters a white noise for purposes of testing a digital line. Thus, the first
step of the two-step test for analogous art set forth in Kahn, requiring that
the subject reference (i.e., Uchino) be from the same field of endeavor as
Appellants’ invention, is not met. Kahn, 441 F.3d at 986-87.
Step Two of the Two-Step Test
Step two of the two-step test for analogous art set forth in Kahn
requires that one of ordinary skill in the art consider the subject reference
(i.e., Uchino) to be reasonably pertinent to the problem with which the
inventor was concerned.
Appellants are correct that Uchino is not reasonably pertinent to the
problem faced by Appellants of providing improved and more natural
sounding comfort noise in a digital cellular telephone environment (see FF
3). Uchino is concerned with generating a test signal to test a digital line
using filter coefficients based on fixed amplitudes (see FF 5), and one of
ordinary skill in the art faced with the problem of improving comfort noise
characteristics would not have been reasonably expected to look to the test
signal system and method of Uchino for help with generating a noise signal
in a cellular phone system that varies in amplitude based on varying sub-
band signal amplitudes in order to create a more natural comfort noise.
Appeal 2009-0846
Application 10/645,360

11
In other words, one of ordinary skill in the art would not have
found Uchino’s wander generator and test system reasonably pertinent
to Appellants’ problem of overcoming the disadvantages of noticeable
comfort noise on a cellular telephone call, such as in the system and
method of Swaminathan (see generally FF 2, 3, and 7). Kahn, 441
F.3d at 986-87. The ordinarily skilled artisan would not have found a
QMF filter bank that generates a test signal which fluctuates along the
power spectrum density distribution characteristic useful in
overcoming the problem of producing a more natural comfort noise in
a digital cellular telephone and speech signal environment
encountered by Appellants and/or Swaminathan. Thus, step two of
the two-step test for analogous art is not met.
For all of the foregoing reasons, the Examiner erred in determining
that Uchino is analogous art and is therefore combinable with Swaminathan.
Appellants aptly state that “the rejection comes down to an assertion
that it is obvious to generate comfort noise in the manner that the Uchino et
al. publication generates test signals” (Br. 6). One of ordinary skill in the
art, looking at Swaminathan’s disclosure of a digital cellular telephone
apparatus and method for generating comfort noise, which seeks to provide a
comfort noise that more closely matches actual background noise (see FF 7),
would not have found it obvious to follow Uchino’s disclosure of generating
a test signal to test a digital line using filter coefficients based on fixed
amplitudes (see FF 5), to produce the result sought by the Appellants of
providing an improved comfort noise generator which approximates spectral
content of actual noise during a call by shaping white noise with a QMF
filter bank according to a variable noise coefficient (see FF 1, 3 and 4).
Appeal 2009-0846
Application 10/645,360

12
Because Uchino and Appellants’ claimed invention (and
Swaminathan) are from divergent fields of endeavor and are not concerned
with solving similar problems, Uchino is non-analogous art, and it would not
have been obvious to combine Uchino with Swaminathan to achieve the
claimed invention. Accordingly, the Examiner failed to establish a prima
facie case of obviousness with respect to claims 1 to 10. See Rijckaert,
9 F.3d at 1532 (internal citations omitted) (stating that “the examiner bears
the initial burden of presenting a prima facie case of obviousness”). In view
of the foregoing, Appellants have shown that the Examiner erred in
determining that Swaminathan and Uchino are combinable, and therefore
teach or suggest the QMF feature which occurs in independent claims 1 and
6. The same holds true for all of the other dependent claims on appeal
because they include the noted QMF feature.
The Examiner’s conclusory statement that it would have been obvious
to modify Swaminathan with Uchino “in order to generate a noise signal
that fluctuates along the power spectrum density distribution characteristic
of the frequency fluctuations of the receive or transmit channel” (Ans. 4 and
6) (emphasis added), does not constitute “‘articulated reasoning with some
rational underpinning to support the legal conclusion of obviousness.’”
KSR, 127 S. Ct. at 1741. The Examiner has not provided a rational basis as
to why the ordinarily skilled artisan concerned with comfort noise in a
cellular phone environment would have looked to a test signal generator to
solve the problem of filtering the comfort noise or making it seem more
natural. We agree with Appellants that there is no basis for the combination
(see Br. 5 and 7). Therefore, the Examiner has failed to provide a prima
Appeal 2009-0846
Application 10/645,360

13
facie case of obviousness with respect to claims 1 to 10. See Oetiker, 977
F.2d at 1445; Bell, 991 F.2d at 783.
Appellants’ burden of demonstrating error in the Examiner's position
with regard to claims 1 to 10 has been met. See Kahn, 441 F.3d at 985-86.

CONCLUSIONS OF LAW
For the foregoing reasons, Appellants have shown that the Examiner
has not presented a rational basis for combining the digital communication
system of Swaminathan with the test signal method and apparatus of Uchino
as required by claims 1 to 10.

ORDER
We reverse the Examiner’s obviousness rejections of claims 1 to 10
under § 103(a).

REVERSED

KIS

PAUL F. WILLE
6407 EAST CLINTON ST.
SCOTTSDALE, AZ 85254