Ex Parte Thomas et al

Patent Trial and Appeal Board

Sep 26, 2013

11233636 (P.T.A.B. Sep. 26, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
_____________

Ex parte JOHN K. THOMAS, MICHAEL L. McCLOUD, and
VIJAY NAGARAJAN
____________________

Appeal 2011-000665
Application 11/233,636
Technology Center 2600
____________________

Before JOSEPH F. RUGGIERO, JASON V. MORGAN, and
TREVOR M. JEFFERSON, Administrative Patent Judges.

JEFFERSON, Administrative Patent Judge.

DECISION ON APPEAL

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STATEMENT OF THE CASE
1

Appellants appeal under 35 U.S.C. § 134(a) from a Final Rejection of
claims 1-90.
2
We have jurisdiction under 35 U.S.C. § 6(b).
We affirm-in-part the Examiner’s rejections.
Introduction
The claims are directed to interference cancellation in received
wireless communication signals using optimal feedback weighting for soft-
decision cancellers for optimally forming a composite interference signal for
use in any subtractive or projective interference canceller. Spec. at page 2-3
(Field of Invention and Summary of Invention). Claim 1, reproduced below
with emphases added, is illustrative of the claimed subject matter:
1. A receiver, comprising:
• an SINR [signal-to-interference-and-noise ratio]
measurement module configured for producing a plurality of
SINR measurements corresponding to a plurality of soft symbol
estimates from a received multipath signal,
• a weight and threshold module configured for
producing a plurality of processed symbol estimates
corresponding to pluralities of multipaths and subchannels,
each processed symbol estimate comprising a hard estimate or
a weighted soft estimate based on a predetermined SINR
threshold,
• an interference-cancellation module configured for
producing a plurality of interference cancelled signals, each
corresponding to a different multipath, and
• a combining module configured for combining the
plurality of interference-cancelled signals.

1
Throughout the decision, we refer to the Appellants’ Appeal Brief (“App.
Br.,” filed Apr. 27, 2010), and Reply Brief (“Reply Br.,” filed Jul. 30, 2010),
and the Examiner’s Answer (“Ans.,” mailed Jun. 11, 2010).
2
The Real Party in Interest is Rambus, Inc. App. Br. 2.
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Rejections
The Examiner made the following rejections:
Claims 1-3, 5, 11-13, 15-21, 23, 29-42, 44, 49-51, 53-58, 60, 66-68,
70-76, 78, 84-86, and 88-90 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Petrus (U.S. 6,177,906 B1, Jan. 23, 2001) and Park (U.S.
2005/0111566 A1, May 26, 2005). Ans. 4-9.
Claims 4, 22, 43, 59 and 77 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Petrus, Park and Black (U.S. 7,010,073 B2, Mar. 7,
2006). Ans. 9-10.
Claims 6, 7, 24, 25, 45, 46, 61, 62, 79 and 80 stand rejected under 35
U.S.C. § 103(a) as being unpatentable over Petrus, Park and Barton (U.S.
6,449,246 B1, Sep. 10, 2002). Ans. 10-11.
Claims 8, 26, 47, 63 and 81 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over Petrus, Park and Bottomley (U.S. 7,397,842 B2, Jul.
8, 2008). Ans. 11-12.
Claims 9, 10, 14, 27, 28, 48, 52, 64, 65, 69, 82, 83 and 87 stand
rejected under 35 U.S.C. § 103(a) as being unpatentable over Petrus, Park
and Abe (U.S. 7,027,533 B2, Apr. 11, 2006). Ans. 12-13.

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ANALYSIS
Claim 1 – 35 U.S.C. § 103(a)
Appellants argue independent claims 1, 19, 40, 56 and 74, which all
contain similar limitations, together. App. Br. 6. We select claim 1 as
representative.
Issue: Did the Examiner err in finding that Petrus teaches or suggests
a weight and threshold module configured for producing a
plurality of processed symbol estimates corresponding to
pluralities of multipaths and subchannels, each processed
symbol estimate comprising a hard estimate or a weighted soft
estimate based on a predetermined SINR threshold,
as recited in claim 1? App. Br. 7 (emphasis added).
Appellants contend that the Examiner erred in finding that Petrus
teaches or suggests “a hard estimate or a weighted soft estimate based on a
predetermined SINR threshold” because Petrus does not teach or suggest a
hard decision at all. App. Br. 7. Reply Br. 4. Appellants argue that the
Examiner erred by finding that claim 1 does “not specify that a selection
needs to be made between ‘a hard estimate’ and ‘a weighted soft estimate
based on a predetermined SINR threshold.’” Reply Br. 5. Appellants
contend that the claim language requires “each processed symbol estimate to
comprise one of two things based on a predetermined SINR threshold: (1) a
hard estimate; or (2) a weighted soft estimate.” Reply Br. 6. Appellants
further contend that the Specification at page 12 supports this interpretation
and not the Examiner’s findings that a hard estimate is just an alternate
solution for a weighted soft symbol estimate. Reply 6-7 (discussing Ans.
14).
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The Examiner answers that Petrus teaches or suggests that a
determination is made at step 311 on whether the estimated SINR 309 has
exceeded a threshold. Ans. 14 (citing Petrus, col 14, ll. 60 to col. 15, ll. 23,
Fig. 3). The Examiner finds that where the SINR exceeded the threshold a
weighted vector was in the demodulation step 319 that is equivalent to the
claimed weighted soft estimate based on a predetermined SINR threshold.
Id. The Examiner also finds that the language of the claims does not require
that a “selection needs to be made between ‘a hard estimate’ and ‘a
weighted soft estimate based on a predetermined SINR threshold.’” Id. The
Examiner asserts that Appellants’ Specification (page 12, last para., and
page 13, first para.) support that the hard estimate is an alternate solution for
the weighted soft symbol estimate. Id.
Appellants’ contention turns on the claim construction of “a hard
estimate or a weighted soft estimate based on a predetermined SINR
threshold.” We give the claim its broadest reasonable interpretation
consistent with the Specification. See In re Morris, 127 F.3d 1048, 1054
(Fed. Cir. 1997).
Though understanding the claim language may be aided by
explanations contained in the written description, it is important
not to import into a claim limitations that are not part of the
claim. For example, a particular embodiment appearing in the
written description may not be read into a claim when the claim
language is broader than the embodiment.
Superguide Corp. v. DirecTV Enterprises, Inc., 358 F.3d 870, 875 (Fed Cir.
2004) (citing Electro Med. Sys. S.A. v. Cooper Life Sci., Inc., 34 F.3d 1048,
1054 (Fed. Cir. 1994)).
We agree with the Examiner (Ans. 14) and interpret the claim
limitation for “a hard estimate or a weighted soft estimate based on a
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predetermined SINR threshold” as using alternative language that only
requires either a hard estimate or a weighted soft estimate based on the
threshold but not both. Although Appellants’ Specification describes that a
threshold “may” define the conditions for use of the hard or soft estimates
(Spec. page 12), we decline to limit the plain language of the claims, which
is broader than the Specification embodiment.
We also agree with the Examiner that Petrus teaches “a weighted soft
estimate based on a predetermined SINR threshold” as recited in claim 1.
We agree with the Examiner findings that Petrus teaches that SINR is
estimated and used in determination to apply a soft weighting method. Ans.
14. Indeed, Appellants agree that Petrus “describe[s] the process of
comparing the SINR to a threshold to determine when to transition from one
soft weighting method to another.” App. Br. 7. Accordingly, we find the
Examiner did not err in finding that Petrus teaches or suggests
a weight and threshold module configured for producing a
plurality of processed symbol estimates corresponding to
pluralities of multipaths and subchannels, each processed
symbol estimate comprising a hard estimate or a weighted soft
estimate based on a predetermined SINR threshold,
as recited in claim 1?

Issue: Did the Examiner err in finding that Park teaches or suggests
an interference-cancellation module configured for producing a
plurality of interference cancelled signals, each corresponding
to a different multipath, and a combining module configured for
combining the plurality of interference-cancelled signals
as recited in claim 1? App. Br. 10-11; Reply Br. 9-11.
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Appellants contend that the Examiner erred in finding that Park
teaches “a combining module configured for combining the plurality of
interference-cancelled signals.” App. Br. 10-11; Reply Br. 9-11. Park,
¶¶ [0032]-[0045] and Figure 1, does not show a plurality of interference
cancelled signals and only “teaches that the output of the MCI [Multi-Code
Interference] cancellation block [of Fig. 1] is a plurality of signals sorted by
antenna and spreading code, not by multipath.” Reply 10. In addition, Park
and Petrus fail to teach that the interference signals are combined as “the
parallel-to-serial converter [disclosed in Park, Fig. 1] merely alters the
processing of the plurality of interference cancelled signals from parallel
processing to serial processing; it does not combine the plurality of
interference signals.” App. Br. 12.
We are not persuaded by Appellants’ arguments that the Examiner
erred. We agree with the Examiner that Park teaches that the output signals
of the MCI cancellation block in a receiver with multiple antennas are
interference cancelled signals. Ans. 15 (citing Park, Fig. 1). We find that
the signals from the multiple antennas sent via the “Successive MCI
cancellation with V-BLAST [vertical Bell Labs layered space-time]
detection” block of Figure 1 into the “Parallel-to-Serial converter” teach a
plurality of interference cancelled signals that are combined by the
converter. See Park, ¶¶ [0031], [0032] and Fig. 1; see also Ans. 5, 15-16.
Appellants have not provided sufficient or persuasive evidence that the
interference cancellation block in Figure 1 of Park does not teach or suggest
the combination of a plurality of interference cancelled signals as claimed.
Based on the foregoing, we find that the Examiner did not err in
finding that Park teaches or suggests
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an interference-cancellation module configured for producing a
plurality of interference cancelled signals, each corresponding
to a different multipath, and a combining module configured for
combining the plurality of interference-cancelled signals
as recited in claim 1.

Issue: Did the Examiner err in finding the motivation to combine
Petrus and Park because the Examiner has not provided a rationale
underpinning to the combination as applied to claim 1? App. Br. 12; Reply
Br. 16-17.
With respect to claim 1, Appellants argue that “the Examiner does not
explain how modifying Petrus in the manner asserted would in fact allow an
effective detection algorithm in a BLAST system.” App. Br. 17. Appellants
assert that Examiner provides no reasoning why one of ordinary skill in the
art would modify Petrus with Park or how those modifications meet the
objective of Park. App. Br. 18.
The Examiner answers that both Petrus and Park disclose a receiver
with multiple antennas in a wireless communication system. Ans. 16. The
Examiner finds that it would have been obvious for one of ordinary skill in
the art at the time of Appellants’ invention to modify the Petrus invention
(the weighted vector applied to soft symbols based on the SINR threshold)
by adding Park’s interference-cancellation method “to eliminate as much as
possible the interferences for better signal quality.” Ans. 16; see also Ans. 5
(citing Park, ¶ [0012]).
We are not persuaded by Appellants’ arguments that the Examiner has
not provided explicit motivation to modify or teachings on how to modify
the Petrus and Park reference. See KSR Int’l Co. v. Teleflex, Inc., 550 U.S.
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398, 418 (2007) (rejecting rigid inquiry into motivation to combine
references). The Court has held that the combination of familiar elements
according to known methods is likely to be obvious when it does no more
than yield predictable results. Id. at 416. In the present case, Appellants
have not presented convincing evidence that the combination of Petrus and
Park was “uniquely challenging or difficult for one of ordinary skill in the
art.” See Leapfrog Enters., Inc. v. Fisher-Price, Inc., 485 F.3d 1157, 1162
(Fed. Cir. 2007) (citing KSR, 550 U.S. at 418).
Our inquiry for whether the Examiner erred in the combination of
Park and Petrus is: has the Examiner provided “some articulated reasoning
with some rational underpinning to support the legal conclusion of
obviousness.” KSR, 550 U.S. at 418 (citing In re Kahn, 441 F.3d 977, 988
C.A.Fed.2006)). “The test for obviousness is not whether the features of a
secondary reference may be bodily incorporated into the structure of the
primary reference. . . . Rather, the test is what the combined teachings of the
references would have suggested to those of ordinary skill in the art.” In re
Keller, 642 F.2d 413, 425 (CCPA 1981). On the record before us, we find
that the Examiner has provided reasoning with some rational underpinning
to combine Park and Petrus, namely “to eliminate as much as possible the
interferences for better signal quality.” Ans. 16. Accordingly, the Examiner
did not err in combining Park and Petrus.
Based on the foregoing, we sustain the Examiner’s rejection of
independent claim 1 and independent claims 19, 40, 56 and 74 under 35
U.S.C. § 103(a) as being unpatentable over Petrus and Park.

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Dependent Claims 2 and 3 – 35 U.S.C. § 103(a)
Issue: Did the Examiner err in finding that Petrus and Park teach or
suggest a “threshold calculation module” as recited in claims 2 and 3? App.
Br. 13-14; Reply Br. 12.
Appellants contend that the Examiner has failed to show that Petrus
teaches the claim 2 recitation of a module for determining the predetermined
SINR threshold of claim 1. Br. 13-14; Reply Br. 12. Petrus uses a
predetermined threshold but does not teach “determining the predetermined
SINR threshold nor determining an SINR below which weighted soft
decisions” are used. App. Br. 14.
We agree with Appellants. We note that the Examiner provided no
response to Appellants’ arguments for error. The Examiner’s rejection,
however, merely refers to the use of the SINR threshold in Figure 3. Ans. 6
(citing Petrus, col. 19, ll. 25-30, Fig. 3 (item 311)). The portions of Petrus
cited do not teach the determination of the threshold value. We disagree
with the Examiner’s findings that Petrus teaches “a threshold calculation
module” that determines the threshold values of claim 1. See id. Therefore,
we cannot sustain the Examiner’s rejection of dependent claims 2 and 3. We
also cannot sustain the Examiner’s rejection of claims 20, 21, 41, 42, 57, 58,
75, and 76, which all contain similar limitations. Accordingly, we reverse
the Examiner’s rejection of claims 2, 3, 20, 21, 41, 42, 57, 58, 75, and 76
under 35 U.S.C. § 103(a) as being unpatentable over Petrus and Park, and
the claims that depend therefrom, claims 4, 22, 43, 59, and 77.

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Dependent Claim 5 – 35 U.S.C. § 103(a)
Issue: Did the Examiner err in finding that Petrus and Park teach or
suggest “weighting at least one of the plurality of soft symbol estimates” as
recited in claim 5? App. Br. 13-14; Reply Br. 13.
Appellants contend that the Examiner has failed show that Petrus
teaches “a weight computation module configured for generating at least one
weight for weighting at least one of the plurality of soft symbol estimates” as
recited in dependent claim 5. Br. 14-15; Reply Br. 12. Appellants argue
that the weights relied on by the Examiner in Petrus (col. 18, ll. 18-49, Fig.
6, item 615) are not weights applied to soft symbol estimates. Reply Br. 13.
The Examiner provides no response to Appellants’ arguments for
error with respect to claim 5. Reviewing the record before us, we do not
agree with the Examiner’s finding that item 615 of Fig. 6 (see Petrus, col.
18, ll. 18-49) teaches or suggests weighting of a soft symbol estimate.
Accordingly, we do not sustain the Examiner’s rejection of dependent claim
5. Similarly, we also do not sustain the Examiner’s rejection of dependent
claims 23, 44, 60, and 78, which all contain similar limitations. Based on
the foregoing, we reverse the Examiner’s rejection of dependent claims 5,
23, 44, 60, and 78 under 35 U.S.C. §103(a) as being unpatentable over
Petrus and Park, and the claims that depend therefrom, claims 6-8, 24-26,
45-47, 61-63, 79-81.

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Dependent Claim 11 – 35 U.S.C. § 103(a)
Issue: Did the Examiner err in finding that Petrus and Park teach or
suggest “estimating an error vector magnitude” as recited in claim 11? App.
Br. 15.
Appellants contend that the Examiner has failed to show that Petrus
teaches “the SINR measurement module is configured for estimating an
error vector magnitude” as recited in dependent claim 11. App. Br. 15;
Reply Br. 13-14. Appellants argue that the Examiner’s citations to Petrus
disclose synchronization timing errors which differ from the error vector
magnitude known in the art as a method of computing SINR. App. Br. 15.
The Examiner again provides no response to Appellants’ arguments
for error with respect to claim 11. Reviewing the record before us, we agree
with the Appellants that the Examiner’s evidence refers to timing errors, not
error vector magnitude as claimed. See Ans. 7 (citing Petrus, col. 11, ll. 9-
22 and Fig. 8). Accordingly, we do not sustain the Examiner’s rejection of
dependent claim 11. We also do not sustain the Examiner’s rejection of
dependent claims 29, 49, 66 and 84, which all contain similar limitations.
Thus, we reverse the Examiner’s rejection of claims 11, 29, 49, 66, and 84
under 35 U.S.C. § 103(a) as being unpatentable over Petrus and Park.

Dependent Claim 12 – 35 U.S.C. § 103(a)
Issue: Did the Examiner err in finding that Petrus and Park teach or
suggest “perform[ing] quantized scaling” as recited in claim 12? App. Br.
16.
Appellants contend that Petrus teaches that the scale factors the
Examiner cites for quantized scaling are applied in combination as a gain in
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the system and not as part of the cited weight and threshold module as
claimed. App. Br. 16 (citing Petrus, col. 10, ll. 27-32).
The Examiner provided no response to Appellants’ contentions of
error. Based on the record before us, we find that the Examiner has not
provided convincing evidence that Petrus teaches “a weight and threshold
module is configured to perform quantized scaling” as recited in dependent
claim 12. App. Br. 16; Reply Br. 13-14. Accordingly, we do not sustain the
Examiner’s rejection of dependent claim 12. We also do not sustain the
Examiner’s rejection of dependent claims 30, 50, 67 and 85, which all
contain similar limitations. For the above reasons, we reverse the
Examiner’s rejection of claims 12, 30, 50, 67 and 85 under 35 U.S.C.
§ 103(a) as being unpatentable over Petrus and Park.

Dependent Claim 15 – 35 U.S.C. § 103(a)
Issue: Did the Examiner err in finding that Petrus and Park teach or
suggest that “the combining module is configured for performing maximal
ratio combining” as recited in claim 15? App. Br. 16-17.
Appellants contend that Petrus does not teach “maximal ratio
combining” which has a particular meaning in the art. App. Br. 16-17.
Appellants further contend that the portion of Park cited by the Examiner
(¶ [0016]) only teaches “the computation of a power ratio between the
transmit power of two adjacent spreading codes.” App. Br. 16. The
Examiner provides no answer to Appellants’ arguments for error.
We agree with Appellants. The portion of Park, ¶ [0016], fails to
persuade us that Park teaches or suggest “maximal ratio combining” as
claimed or cited in Appellants'’ Specification (see Spec. at page 3). Based
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on the foregoing, we do not sustain the Examiner’s rejection of dependent
claim 15. We also do not sustain the Examiner’s rejection of dependent
claims 32, 53, 70, and 88, which all contain similar limitations.
Accordingly, we reverse the Examiner’s rejection of claims 15, 32, 53, 70,
and 88 under 35 U.S.C. § 103(a) as being unpatentable over Petrus and Park.

Remaining Dependent Claims – 35 U.S.C. § 103(a)
With respect to dependent claims 9, 10, 13, 14, 16-18, 27, 28, 31, 33-
39, 48, 51, 54, 55, 64, 65, 68, 69, 71-73, 82, 83, 86, 87, 89, and 90,
Appellants make no separate arguments apart from those presented with
respect to claim 1. See App. Br. 10, 12. Based on the foregoing discussion
with respect to independent claim 1, we affirm the Examiner’s rejection of
claims 9, 10, 13, 14, 16-18, 27, 28, 31, 33-39, 48, 51, 54, 55, 64, 65, 68, 69,
71-73, 82, 83, 86, 87, 89, and 90.

DECISION
For the above reasons, we:
AFFIRM the Examiner’s rejection of independent claims 1, 19, 40, 56
and 74;
AFFIRM the Examiner’s rejection of dependent claims 9, 10, 13, 14,
16-18, 27, 28, 31, 33-39, 48, 51, 52, 54, 55, 64, 65, 68, 69, 71-73, 82, 83, 86,
87, 89 and 90; and
REVERSE the Examiner’s rejection of dependent claims 2-8, 11, 12,
15, 20-26, 29, 30, 32, 41-47, 49, 50, 53, 57-63, 66, 67, 70, 75-81, 84, 85 and
88.
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No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv) (2011).

AFFIRMED-IN-PART

ELD