Ex Parte Vassiliou et al

Board of Patent Appeals and Interferences

Oct 14, 2009

10654199 (B.P.A.I. Oct. 14, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte IASON VASSILIOU, THEODORE GEORGANTAS, AKIRA
YAMANAKA, KONSTANTINOS VAVELIDIS, and SOFOKLIS
PLEVRIDIS
____________

Appeal 2009-002372
Application 10/654,199
Technology Center 2600
____________

Decided: October 14, 2009
____________

Before ROBERT E. NAPPI, KARL D. EASTHOM, and THOMAS S.
HAHN Administrative Patent Judges.

EASTHOM, Administrative Patent Judge.

DECISION ON APPEAL

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STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of
claims 1-48 (App. Br. 2).1 We have jurisdiction under 35 U.S.C. § 6(b).
We affirm-in-part.

The Disclosed Invention
Appellants’ invention provides multiple types of calibration to a
transceiver to overcome problems based on different characteristics between
non-ideal components. One aspect of the calibration corrects for channel
mismatch, which refers to the difference in phase and gain between the in-
phase I and quadrature Q channel paths in receiver 30 and transmitter 32 of a
transceiver system (Fig. 2). The invention also provides DC offset
calibration, filter tuning, and LO leakage calibration. DACS (digital to
analog controllers), responsive to control signals from processor 18, can tune
receiver and transmitter filter responses to a desirable cutoff frequency and
bandwidth so that the filters in the I and Q branches match one another.
(Abstract; Fig. 2; Spec. 2:10-13; 13:11-16; 16:17 to 17:2; 18:15-19).

The Claims
Exemplary claims 1, 5, and 6 follow:
1. A transceiver for transmitting and receiving signals, the
transceiver comprising:

1 Appellants’ Brief (filed Oct. 15, 2007) (“App. Br.”) and Reply Brief (filed
Mar. 11, 2008), and the Examiner’s Answer (mailed Jan. 11, 2008) (“Ans.”)
are referenced here.
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a transmitter operative to up-convert baseband signals from a
baseband frequency into RF signals at a radio frequency (RF) frequency and
output the RF signals;
a receiver operative to receive RF signals and down-convert the RF
signals into baseband signals having the baseband frequency; and
a plurality of calibration paths coupling the transmitter to the
receiver, wherein one or more of the calibration paths can be selected to be
active when calibrating components of the transceiver using one or more of
a plurality of calibration methods.
5. The transceiver of claim 1 comprising baseband analog receive
filters which have responses which can be measured for calibration using the
one of the calibration paths.
6. The transceiver of claim 5 comprising digital-to-analog converters
(DACs) coupled to the receive filters, and controllable to tune the receive
filters based on the measurements of the receive filters over the calibration
path.
Prior Art and Rejections2
Lin US 2004/0038649 A1 Feb. 26, 2004
Khlat US 2004/0071238 A1 Apr. 15, 2004
Kerth US 6,804,497 B2 Oct. 12, 2004
Lehning US 2005/0107059 A1 May 19, 2005
Shi US 7,110,649 B2 Sept. 19, 2006

Claims 1, 5-7, 13-15, 17, 20, 26, 27, 33-35, 38-42 and 44-46 stand
rejected as anticipated under 35 U.S.C. § 102(e) based on Lehning.
Claims 2-4, 8, 9, 11, 21-25, 28, 29 and 43 stand rejected as obvious
under 35 U.S.C. § 103(a) based on Lehning and Lin.
Claims 16, 36, 37, 47 and 48 stand rejected as obvious under 35
U.S.C. § 103(a) based on Lehning and Khlat.

2 The filing dates of these documents each precede Appellants’ earliest
possible effective filing date and are not at issue.
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Claims 10, 12 and 30-32 stand rejected as obvious under 35 U.S.C. §
103(a) based on Lehning, Lin and Shi.
Claims 18 and 19 stand rejected as obvious under 35 U.S.C. § 103(a)
based on Lehning and Kerth.

PRINCIPLES OF LAW
“[T]he examiner bears the initial burden, on review of the prior art or
on any other ground, of presenting a prima facie case of unpatentability.” In
re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). “[A]fter the PTO
establishes a prima facie case of anticipation . . ., the burden shifts to
appellant to prove that the subject matter shown to be in the prior art does
not possess the characteristic relied upon.” In re King, 801 F.2d 1324, 1327
(Fed. Cir. 1986) (internal quotation marks omitted).
Under § 103, a holding of obviousness can be based on a showing that
“there was an apparent reason to combine the known elements in the fashion
claimed.” KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007). Such a
showing requires: “some articulated reasoning with some rational
underpinning to support the legal conclusion of obviousness.” Id. (quoting In
re Kahn, 441 F.3d 977, 988 (Fed. Cir. 2006)).
On appeal, the burden shifts to Appellants to overcome the prima
facie showing with argument and/or evidence. Obviousness is then
determined on the basis of the evidence as a whole and the relative
persuasiveness of the arguments. Oetiker, 977 F.2d at 1445.

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ISSUES
Appellants contend that each of the claims is allowable because the
references fail to teach certain recited limitations. These contentions are
addressed below, claim by claim, or in groups as appropriate. Primarily,
with respect to the anticipation rejection of claim 1, Appellants assert (App.
Br. 8-12) that Lehning does not disclose the limitations set forth in the final
clause. The issues presented on appeal are:
1) Did Appellants demonstrate that the Examiner erred in finding that
Lehning discloses “a plurality of calibration paths coupling the transmitter to
the receiver, wherein one or more of the calibration paths can be selected to
be active when calibrating components of the transceiver using one or more
of a plurality of calibration methods” as recited in claim 1?
2) Did Appellants demonstrate Examiner error in the rejections of
claims 2-48, which involve, inter alia, limitations directed to calibration,
processor control, filters, oscillator leakage, and various receiver and
transmitter connections and calibration paths?

FINDINGS of FACT (FF)
Lehning
1. Lehning discloses:
a method of signal mismatch compensation comprising: applying a
first training signal, of known characteristics, to a circuit which
includes at least one filter, receiving a filtered training signal, from the
circuit, deriving a transfer function from the received filtered signal;
obtaining the inverse transfer function and applying the inverse
transfer function to a subsequently received signal in order to correct
any signal mismatch in the subsequently received signal. (¶0029).

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“These mismatches are due to slight differences in the values and
behavior of active and passive elements found in I and the Q signal paths, . .
. . [and] are even more pronounced . . . [due to] thermal drift” (¶0014).
Compensation of the two (I, Q) filter pairs in each of the transmitter and
receiver paths accounts for undesired amplitude and phase changes in each I
path as compared to its corresponding Q path (see ¶¶ 0089, 0103).
To perform this mismatch compensation, Lehning discloses four paths
controlled by a processor/DSP (FF 2; FF 5; Fig. 19). The processor
generates “FILTER TEST” (T-Rx and T-Tx) switch controls signals, thereby
allowing I and Q test signals to route to either the receiver or transmitter
filters, and then, last, to the final receiver switch, and ultimately to a
processor and receiver OFDM demodulator (¶¶ 0082, 0096, Figs. 1G; 8, 9).
In particular, the I and Q (processor generated and measured) test signals (¶¶
0064, 0067, 0077, 0080, 0094) are routed from the transmitter (I-Tx and Q-
Tx TRANSMIT) side through the different switch paths (S8-S14, not
numbered in Figs. 8, 9, but described in ¶¶0081 and 0095) to the receiver in
the transceiver system (see also Fig. 1G). Thus, two paths serve for testing
receiver I and Q low pass filters (LPFs) (Fig. 8), while two other paths serve
for testing the transmitter I and Q low pass filters (LPFs) (Fig. 9).
In sum, the test signals pass from the DSP to the transmitter Tx and
then to the receiver Rx OFDM demodulator, either through the receive I and
Q LPF filters (Fig. 8), or through the transmit I and Q LPF filters (Fig. 9).
In both cases, “the I and Q training components can be transmitted and
received simultaneously” (¶0081; accord ¶0095). (See also ¶¶0030-32;
0080-82, 0094-96, and infra FF 2-6).
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2. Lehning discloses: “Firstly there is correction of Low Pass filter
mismatches. . . . preferably performed under digital control from a base
band processor by a measurement and compensation procedure. Secondly
there is correction of mixer and oscillator mismatches. . . . by additional
hardware at the analog section of the transceiver.” (¶0064) (emphasis
added). Lehning specifically discloses microprocessor switch control
(¶0025, claim 8 at ¶0114). Lehning also discloses “Digital Signal
Processing for receive path Filter compensation . . . with reference to Fig. 8”
(¶0080) and “Digital Signal Processing for transmit path Filter
precompensation” (¶0094) in reference to Fig. 9 (¶0095). “The training
signal (St) is generated in the DSP” (¶0077).
3. The compensation parameters MR(i), generated by the DSP (see
also FF 2, 4) in the form of a (4, 4) matrix, are applied to each pair of
receive sub-carriers in a data packet to obtain mismatch post-compensated
received I and Q subcarriers (¶¶ 0080, 0086-88). Compensation parameters
MT(i) in the form of another (4,4) matrix are applied to each pair of
transmitted subcarriers in a data packet to pre-compensate mismatched I and
Q transmitted subcarriers (¶¶0094, 0100-102).
4. Lehning further describes the processor control of the digital
signals to compensate for mismatch:
In the case of digital I-Q mismatch or separation, the
base-band signal is in digital form (after analog to digital
conversion) and is then fed to a digital signal processor 100
(DSP) which in turn creates the necessary I and Q signals using
appropriate digital signal processing. There are no
imperfections related to component mismatches in the digital
domain. Only quantisation noise (due to the digital number
representation) can cause deleterious effects.
(¶ 0067).
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5. “The expressions Digital Signal Processor (DSP’s) and base-band
controller are used synonymously . . . .” (¶ 0034). “It will be appreciated
that DSP architecture may vary from a dedicated state machine to a generic
software driven procedure” (¶ 0035).
6. The test (or training) signals travel from the DSP (or generic
processor (FF 5)) through separate I and Q digital to analog converters
(DACs) (Figs. 19, 20; ¶¶ 0031-32; 0064, 0067; claims 12 and 20 at ¶ 0114).
Appellants’ Disclosure
7. “Calibration methods 20 calibrate the transceiver 16 . . . by
measuring characteristics of transceiver components based on received
calibration signals by and [sic] computing the necessary correction
parameters for the calibration of the transceiver 16 to correct any analog
imperfections in the circuits.” (Spec. 13:22 to 14:2).

Khlat
8. Khlat teaches correcting for DC offset in a receiver. The method
provides a DC adapt input 6 to a DAC 64, which in turn supplies DC offset
correction in the form of an analog signal to the input of an amplifier 56
(Fig. 2). This correction employs feedback to reduce the DC offset in the
amplifier and its downstream signal path. This signal path includes an active
LPF, a band pass filter, and mixers for I or Q channels, each of which
otherwise contribute to the DC offset (Absract, Fig. 2, ¶¶ 0002, 0019).

Lin
9. Lin discloses “an absolute magnitude circuit 146 . . . .” (¶ 0052).

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Shi
10. Shi teaches calibration for a transmitter having I and Q paths
(Abstract; Figs. 4, 5). “The low pass filtering of LPF 128 isolates the
transmitted signal component at DC of the digital baseband signal 132 plus
any DC offset, which is represented by LO leakage 150.” (Col. 8, ll. 19-22).
“The interpreting module 126 interprets the 1st and 2nd frequency spectrum
components . . . to determine the LO leakage component 150” (col. 8, ll. 30-
35). “[T]he interpreting module 126 generates the calibration signal 116 to
correct for DC offset” (col. 8, ll. 42-43).

ANALYSIS
Anticipation Rejection
Claim 1
Appellants’ argument (App. Br. 8-9) that Lehning does not disclose “a
plurality of calibration paths coupling the transmitter to the receiver” as
claim 1 requires is unconvincing. The argument fails to address the
Examiner’s reasonable depiction and description of the four calibration paths
(Ans. 23), based upon Lehning’s Figures 8 and 9 and description thereof
(see FF 1). Appellants base their argument on the assertion (App. Br. 9)
(citing Lehning ¶ 0032) that “the test signal of Lehning is routed to either
the transmit chain or the receive chain (not both).” This assertion,
based on a single statement in Lehning, fails to address the totality of
Lehning’s disclosure as detailed in the Examiner’s findings, including, inter
alia, that Lehning’s test signals travel through various switches and different
switch paths in both the transmitter and the receiver chains (Ans. 22-27)
(comparing Appellants’ Fig. 2 with Lehning’s Fig. 8). These test signals
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travel from the transmitter (as generated by the system DSP) either through
the receiver or transmitter filters (LPFs), and in both cases, ultimately to the
receiver OFDM demodulator and back to the system DSP for processing (FF
1-6). As such, Appellants’ (bolded) statement supra merely refers to
Lehning’s testing of either the receiver filters or the transmitter filters (FF 1-
6). Whether testing the receiver or transmitter LPFs, “the I and Q training
components can be transmitted and received simultaneously.” (FF 1)
(emphasis added).
Notwithstanding Appellants’ related argument (App. Br. 9), Lehning
also discloses several calibration methods. While Appellants argue (id.)
(citing Lehning ¶¶ 0032, 0113) that Lehning employs only a single set of
calibration parameters for filter compensation, Appellants’ argument
references an alternative half-duplex embodiment in which the receiver and
transmitter pair shares the same LPFs (see Lehning, ¶¶ 0030, 0111-113).
However, the Examiner also relied on the full duplex embodiment (e.g.
Lehning Figs. 8 and 9, see also Fig. 1G). This embodiment uses different
paths and a different set of compensation parameters for the transmitter (I,
Q) filters and the receiver (I, Q) filters, thereby constituting separate
methods (see Ans. 5-6, 23-24) (FF 1-6).
More specifically, Lehning employs two different matrices (i.e.
different parameters) for the transmitter and receiver chain (FF 3). As such,
the four separate I and Q paths carry different coefficients. It follows that
Lehning discloses a “plurality of calibration methods.” In addition to
multiple methods for filter compensation, Lehning also discloses different
calibrating methods for “correction of mixer and oscillator mismatches” (FF
2), thereby constituting other methods of the plurality claimed. As such,
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Lehning’s system selects one or more calibration paths using one or more
calibration methods (filter compensations), out of a plurality of such
methods (filter compensations, and/or oscillator or mixer compensations).
Appellants shift their argument (Reply Br. 4) and assert that a
distinction exists between “calibrate” and “compensate.” Appellants have
waived this untimely argument because it is not responsive to a new point in
the Answer.3 Even if the argument were timely, Appellants’ Specification
broadly implies that “calibrate” includes simply measuring and calculating
adjustment parameters (see FF 7). At any rate, Lehning’s compensation
system meets Appellants’ definition (Reply Br. 4) of “calibrate” because it
“adjust[s] precisely for a particular function” of filter mismatch (FF 1-6).
In sum, Appellants did not demonstrate the Examiner erred in finding
that Lehning discloses “a plurality of calibration paths coupling the
transmitter to the receiver, wherein one or more of the calibration paths can
be selected to be active when calibrating components of the transceiver
using one or more of a plurality of calibration methods” as recited in claim
1.
Claim 5
Appellants (App. Br. 13-14) rely on arguments presented for claim 1
and additionally contest the Examiner’s finding (Ans. 6, 27) that Lehning

3 See Optivus Tech., Inc. v. Ion Beam Applications S.A., 469 F.3d 978, 989
(Fed. Cir. 2006) (“[A]n issue not raised by an appellant in its opening brief .
. . is waived.” (citation omitted) (internal quotation marks omitted)); accord
Ex Parte Scholl, No. 2007-3653 at 18-19 (BPAI Mar. 13, 2008)
(Informative), available at
http://www.uspto.gov/web/offices/dcom/bpai/its/fd073653.pdf. (Based on
Optivus and Scholl, Appellants cannot “reserve[ ]the right to argue
additional reasons” (e.g. App. Br. 14)).

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teaches receive filters which have responses that can be measured.
Appellants assert (App. Br. 13-14) that Lehning “simply discloses that a test
signal may be routed to the I and Q paths of the transmit chain or through
the I and Q paths of the receive chain” and “further discloses that the test is
used to compensate frequency mismatch in filters” but does not teach the
claim limitations, without explaining how the Examiner erred.
As similarly discussed below with respect to claim 2, Lehning’s
system sends test signals through the receiver (and transmitter) low pass
filters (LPFs) to “derive[] a transfer function from the received filtered
signal” (FF 1) by measuring the filter output response to create
compensation parameters (see also FF 2-3). Such measurements of I and Q
filter outputs based on inputs thereto constitutes filter responses which can
be measured for calibration (FF 1-6). Thus, Appellants did not demonstrate
that the Examiner erred in finding that Lehning discloses “analog receive
filters which have responses which can be measured for calibration using the
one of the calibration paths” as recited in claim 5.
Claim 6
Appellants (App. Br. 14-16) rely on arguments presented for claim 1
and additionally contest the Examiner’s finding (Ans. 6, 28) that Lehning
discloses “digital-to-analog converters (DACs) coupled to the receive filters,
and controllable to tune the receive filters based on the measurements of the
receive filters over the calibration path” as recited in dependent claim 6.
As Appellants point out (id.), the Examiner relies on the mismatch
compensation teachings of Lehning (Ans. 28) (citing Lehning ¶¶0032, 0064)
(see also FF 1-3) described above with respect to claim 1. However,
Lehning does not discuss tuning in the portions upon which the Examiner
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relies. Lehning’s mismatch correction pre- and post-compensates the
transmitted and received I and Q signals (FF 1-3). As such, in the absence
of an explanation by the Examiner describing how mismatch correction
constitutes tuning, and given the ordinary meaning of filter tuning (see supra
“The Disclosed Invention”), Appellants have demonstrated Examiner error
with respect to claim 6.
Claim 7
Appellants (App. Br. 16) rely on arguments presented for claim 1 and
additionally contest the Examiner’s finding (Ans. 29) that Lehning discloses
that “the selected calibration path is selected to be active by a processor
coupled to the transceiver and which controls the calibrations of the
components of the receiver” as recited in claim 7. The Examiner (Ans. 6,
29) relies on Lehning’s paragraph 0025 as teaching switch control in the
“‘first and second channels. . . . by way of a microprocessor’” as Appellants
acknowledge (App. Br. 16)(quoting Lehning ¶0025 and the Examiner).
Appellants also focus on Lehning’s teachings at paragraph 0067,
asserting that Lehning teaches there that the DSP only creates the I and Q
signals, and not compensation. Appellants unconvincingly read the
paragraph out of context. Lehning states there that, “[i]n the case of digital
I-Q mismatch or separation . . . a . . . (DSP) . . . creates the necessary I and Q
signals” (FF 4) (emphasis added). Additionally, with respect to independent
claim 1 from which claim 7 depends, the Examiner (Ans. 25) also relied
upon and quoted Lehning’s paragraph 0064 to teach “correction of Low Pass
filter mismatches. . . . performed under digital control from a baseband
processor by a measurement and compensation procedure.” (These processor
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references all pertain to the same processor or DSP or processing scheme –
see FF 5).
As Appellants note (Reply Br. 12; see also App. Br. 18-19), the
Examiner also relied upon paragraph 0064 with respect to claim 13
(depending from claim 7) to buttress the teaching of filter compensation by a
processor. Lehning specifically refers to processor control of the
compensation process in several other places: (e.g. “Digital Signal
Processing for receive path Filter compensation;” “Digital Signal Processing
for transmit path Filter precompensation;” “The training signal (St) is
generated by the DSP” (FF 2)).
As such, Appellants have failed to demonstrate error in the
Examiner’s prima facie case that Lehning teaches processor control of the
mismatch compensation (calibration) procedure, including the switches
involved therein (selected calibration path) (FF 1-6; Ans. 6, 25, 29).
Claim 13
Appellants (App. Br. 17) rely on arguments presented for claims 1 and
7 (asserting the lack of the processor limitation), and additionally contest the
Examiner’s finding (Ans. 29) that Lehning discloses that “the loopback
connection allows receive I/Q mismatch to be measured by the processor” as
recited in claim 13. The Examiner (Ans. 6, 29) citing paragraphs 0032,
0064, and 0067, and Figures 22 and 23, apparently relies on Lehning’s
teachings of the receiver and transmitter connections to test for mismatch
compensation as providing the loopback connection. Appellants do not
point to error with particularity and merely repeat the claim limitations
quoted above, asserting that the “claim 13 is allowable over the reference”
(App. Br. 19). Such a mere denial and repetition fails to demonstrate error
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in the Examiner’s prima facie case that Lehning’s receiver and transmitter
connections, all connected to a processor which sends test signals and
receives (measures) filter responses to create compensation parameters,
constitutes a “loopback” connection to the processor (FF 1-6).
Appellants shifted their argument in their Reply Brief (Reply Br. 12),
to allege a lack of teaching with respect to, inter alia, an RF connection, not
argued in the opening Appeal Brief, asserting that Lehning “do[es] not teach
a loopback connection from the RF output of the transmitter to the input of
the receiver, where the loopback connection allows receive I/Q mismatch to
be measured by a processor.” This argument was not necessitated by a new
point in the Answer. By failing to raise it in their Appeal Brief, Appellants
have waived it (supra note 3).
Claim 14
Appellants assert, inter alia, that Lehning does not teach “the
calibration signal is digitally pre-distorted” as set forth in claim 14, (App.
Br. 19) asserting that Lehning teaches “pre-compensation of data packets
prior to transmission” (App. Br. 20). The Examiner does not respond
particularly to this assertion (Ans. 7, 29-30). Appellants’ arguments show
error in the Examiner’s (prima facie) explanation. Lehning’s calibration
method appears to pre-compensate the data packets as opposed to the
calibration signal (FF 3, 4).
Claim 15
On the other hand, claim 15 calls for removing the measured I/Q
mismatch from signals that are received by the receiver by using digital
post-distortion. Lehning’s post compensation procedure, accounting for the
mismatch to retrieve the desired signal, reasonably removes unwanted
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mismatch and teaches the limitation (FF 2-4, compare Ans. 30). Appellants
seem to acknowledge these teachings: summarizing after repeating the
Examiner’s detailed findings (App. Br. 21): “Lehning discloses
compensation of received data packets.” Appellants’ reliance on arguments
for claim 1, and conclusory response (App. Br. 21-22), repeating the
limitations of claim 15 and asserting that claim 15 is allowable, fails to
demonstrate error.
Claim 17
Claim 17 is similar in scope to claims 14 and 15, but recites pre-
distortion elements in generic transmitted signals, as opposed to specifying a
transmitted calibration signal. Appellants maintain (App. Br. 22) that claim
17 is allowable because Lehning does not teach “wherein the filter responses
can be measured such that residual mismatch between two filers can be
removed by digital pre-distortion of a signal to be transmitted.” Lehning’s
system provides pre-compensation to transmitted signals to compensate for
transmitter I and Q low pass filters LPF (FF 1-4). Such pre-compensation
reasonably constitutes pre-distortion (by another name) (compare Ans. 17,
30).
Appellants assert that Lehning teaches that there are “no
imperfections related to component mismatches” (App Br. 23). This
assertion does not relate clearly to any claim limitation. The assertion
appears to be a reference to the Examiner’s findings with respect to
paragraph 0067 – asserting “that residual mismatch between two filters can
be removed by digital pre-distortion of a signal to be transmitted (see
Lehning, para [0067])” (Fin. Rej. 5; Ans. 7)). Appellants’ response does not
account for the purpose of Lehning’s system – to mitigate existing
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component mismatch (i.e. residual) by processing the I and Q signals (FF 1),
as alluded to by the Examiner. As such, Appellants’ reliance on arguments
for claim 1 and conclusory responses (App. Br. 22-23), generally repeating
the limitations of claim 17 and asserting its allowability, fails to demonstrate
error.
Claims 20 and 40
Appellants (App. Br. 23-24, 35-36) repeat certain limitations recited
in claims 20 and 40 and also present the same or similar arguments as
asserted for claim 1. Based on the similar arguments presented, despite the
nominal recitation of claim elements, for the reasons discussed supra,
Appellants did not demonstrate error in the rejection of claims 20 and 40.
Claims 26, 27, 33-35, and 38
These claims recite limitations similar to those recited in claims 7, 13,
15, and 17. Appellants provide similar arguments to similarly disputed
claim limitations. For reasons similar to those outlined supra, Appellants’
reliance on claim 20, and conclusory arguments and summaries of the
Lehning’s teachings and the Examiner’s findings (App. Br. 25-34; Reply Br.
14-15), do not demonstrate that the Examiner (Ans. 8) erred in finding that
Lehning teaches the claim limitations.
In summary, Lehning discloses measuring both transmit and receive I
and Q mismatch using the selected calibration paths, with the processor
controlling all operations and instigating and measuring the digital test
signals and creating compensated signals in response thereto; i.e., using pre-
distortion and post-distortion on transmit and receive signals to compensate
for the mismatches based on the test measurements (FF 1-6). The
transmitter test and return (measured) signals are connected back to the
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processor from which they emanate, constituting the loopback connection of
claims 27 and 33-35.
Claim 39
Appellants repeat the Examiner’s findings and the claim limitations,
and conclude that the claim is allowable (App. Br. 34-35). Measuring
responses at different gain settings and responding accordingly, as required
by the claim, reasonably reads on Lehning by either 1) the different settings,
as evidenced by the different compensation parameters to compensate
therefore in the separate I and Q filters (FF 3); or 2) the different settings and
corresponding post-compensation parameters implicitly generated in each of
the four LPF filters due to thermal drift at different times (FF 1). (See also
FF 2, 4-6). Appellants’ general allegations do not demonstrate error.
Claims 41-42
Appellants repeat the Examiner’s findings and the claim limitations
for claim 41, and conclude that the claim is allowable (App. Br. 37-38).
Appellants do not present separate arguments for claim 42. The Examiner
(Ans. 32-33) responded to Appellants’ arguments as follows: “[T]he
Appellants have repeatedly presented that the test signal of Lehning is routed
via either transmit chain or receive chain, not both. Thus, Lehning teaches
the calibration paths on the transceiver are not active when the transceiver is
not being calibrated (see fig. 1G).” Appellants do not respond to this
reasoning. (This reasoning does not contradict the related findings supra
with respect to claim 1 – i.e., that calibration paths in Figures 8 and 9
connect the transmitter to the receiver, with only two of the paths (either the
I, Q receive paths, or the I, Q transmit paths being used at one time). As
such, Appellants’ general allegations do not demonstrate error.
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Claim 44
As the Examiner notes (Ans. 33), Appellants present arguments (App.
Br. 38-39) presented for claim 1. As such, Appellants’ general allegations
do not demonstrate error.
Claims 45-46
Appellants’ general allegations (App. Br. 39-41) and quotation of the
Examiner’s findings do not demonstrate error. As discussed supra with
respect to claims 5, 7, 27, and 33-35, Lehning discloses processor control
and connection of the receiver filters or the transmitter filters to the
processor for calibration thereof generally as explained by the Examiner
(Ans. 11, FF 1-6).
Obviousness Rejections
Claim 2
Appellants (App. Br. 42) rely on arguments presented for claim 1 to
contest the obviousness rejection of claim 2; asserting Lin does not
overcome the deficiencies of Lehning. Appellants also contest (App. Br. 42)
the Examiner’s finding (Ans. 12) that Lehning teaches “wherein the
transceiver . . . comprises baseband analog transmit filters having responses
which can be measured for calibration using one of the calibration paths” as
recited in claim 2.
Appellants general allegations fail to demonstrate Examiner error.
Test signals sent through the transmitter and/or receiver low pass filters
(LPFs) and measured to create compensation parameters constitute filter
responses which can be measured as discussed supra with respect to claim 5
(FF 1-6). Accordingly, for the reasons discussed above, Appellants have not
demonstrated Examiner error.
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Claim 3
Appellants (App. Br. 43-44) rely on arguments presented for claim 1
to contest the obviousness rejection of claim 3, reciting the limitations of
claim 3, repeating the Examiner’s findings, and asserting Lin does not
overcome the deficiencies of Lehning. Accordingly, the reasons discussed
above, Appellants have not demonstrated Examiner error.
Claim 4
Appellants (App. Br. 44-46) arguments track those for similar claim 6.
Accordingly, for the reasons noted supra, Appellants have demonstrated
Examiner error.
Claims 8-12
Appellants argue (App. Br. 47) that Figures 22-25 of Lehning, upon
which the Examiner relies, “show functional diagrams of transceiver mixer
compensation,” but not the claim 8 limitation of “one of the calibration paths
comprises a loopback connection connected from the RF output of the
transmitter to the processor controlling the calibrations.” Inspection of
those figures supports Appellants, since all connections are below the IF
mixers (i.e. in the baseband). The Examiner points to responses made with
respect to claim 13 (Ans. 34). For claim 13, the Examiner’s response does
not address the “RF output” limitation: “The Examiner submits that Lehning
teaches . . . solving I/Q mismatch via a loopback connection measuring by a
processor.” (Ans. 29). Thus, Appellants have timely demonstrated Examiner
error, unlike the Reply Brief shifted argument for claim 13 (see, supra, p.
15). Claims 9-12 depend from claim 8 and stand accordingly.

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Claims 21-25, 28 and 29
Appellants (App. Br. 50-51) rely on arguments presented for claim 20.
Accordingly, for the reasons discussed supra, Appellants have not
demonstrated Examiner error.
Claims 16, 36, and 37
With respect to claim 16, Appellants argue (App. Br. 53) that
“paragraph 0019 of Khlat only discloses DC offset correction” and “does not
disclose or suggest that DC offset is removed independently for the I and Q
paths of the receiver.” In response (Ans. 35), “the Examiner submits that
Khlat (fig. 2) teaches DAC 64 is adjusted by Digital Fast DC Adapt 62
(para[0018] to remove DC offset (para. [0006]).” This response falls short
of “some articulated reasoning with some rational underpinning,” KSR, 550
U.S. at 418, to explain the “removed independently” feature recited in the
claim, as necessary “to support the legal conclusion of obviousness,” (id.).
Appellants (App. Br. 54-55) and the Examiner (Ans. 35-36) present
similar arguments and responses for claim 36. As such, Appellants have
demonstrated Examiner error in the rejection of claims 16, 36, and 37 which
depends from claim 36.
Claim 43
Appellants (App. Br. 51) rely on arguments presented for claim 40
and also assert that the Examiner “has not provided any substantive
arguments relating to claim 43.” The Examiner (Ans. 15) stated that “the
dependent claim is interpreted and rejected for the same reason as set forth
in claim 8.” However, claim 8 does not recite local oscillator leakage (or
calibration thereof). The Examiner rejected claims 8 and 43 based on
Lehning and Lin (Ans. 12). The Examiner does not rely on either reference
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to teach such leakage calibration (see the rejection of claim 10 (Ans. 17-18),
relying on Shi). Accordingly, Appellants have demonstrated Examiner error
with respect to claim 43.
Claims 47-48
The Examiner and Appellants agree that Khlat discloses DC offset
correction (App. Br. 57-58). Appellants assert that Khlat “does not disclose
or suggest adjusting digital-to-analog converters (DACs) on the transceiver
to calibrate components on the transceiver/, as recited . . . in claim 47.” The
Examiner pointed to teachings in Khlat to support the finding that Khlat
adjusts a DAC to correct for DC offset (see App. Br. 57)(quoting the
Examiner’s findings). Khlat teaches providing a DC adapt input to the
DAC, which in turn supplies a DC offset correction in the form of an analog
signal to the input of an amplifier (FF 8).
Appellants do not explain why the Examiner’s finding is in error.
Absent a clear argument, providing such inputs from a DAC (adjusted to
provide the DC offset input signal) to an amplifier as Khlat discloses,
reasonably meets the claim 47 limitation of calibrating components such as
the amplifier and filters downstream therefrom (which otherwise contribute
to the DC offset) (FF 8). Similarly, providing adjusted or compensated
signals to the receiver and transmitter filters by signals ultimately coming
from DACs as Lehning teaches (FF 1, 6), and the DC offset from a DAC, as
Khlat teaches, reasonably satisfies the limitations of claim 48. Appellants
provide no clear argument demonstrating error.

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Claim 30
Appellants assert (App. Br. 63) that Shi does not teach “estimating the
leakage of a local oscillator” at the column cited by the Examiner (Ans. 19),
and conclude that the combination of Lehning, Lin, and Shi does not
disclose or suggest the limitation of “the calibration of components
comprises estimating the leakage of a local oscillator (LO) included in the
transceiver” as recited in claim 30. However, Shi teaches in the same
column that “[t]he interpreting module . . . interprets . . . frequency . . .
components . . . to determine the LO leakage component 150” (FF 10). The
module then “generates the calibration signal 116 to correct for DC offsets”
in a transmitter (id.) As such, Appellants have not demonstrated error in the
Examiner’s rejection of claim 30.
Claims 31-32
Appellants assert (App. Br. 65) that “[c]omponent 146 of Lin is an
absolute magnitude circuit” such that “Lin, does not disclose or suggest that
LO leakage is estimated from a detected envelope of a calibration signal, as
recited by Applicant in claim 31.” Appellants’ assertion appears founded
(FF 9). The Examiner (see Ans. 19, 37) does not explain how envelope
detection relates to absolute magnitude. As such, Appellants’ arguments
have demonstrated error in the rejection of claim 31, and dependent claim
32.
Claims 18 and 19
Appellants (App. Br. 67-68) rely on arguments presented for claim 1.
Therefore, for reasons explained above with respect to claim 1, Appellants
have not demonstrated Examiner error in the rejection of claims 18 and 19.

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CONCLUSION
Appellants did not demonstrate that the Examiner erred in finding that
Lehning discloses “a plurality of calibration paths coupling the transmitter to
the receiver, wherein one or more of the calibration paths can be selected to
be active when calibrating components of the transceiver using one or more
of a plurality of calibration methods” as recited in claim 1. Appellants also
did not demonstrate Examiner error in the rejections of claims 1-3, 5, 7, 13,
15, 17-30, 33-35, 38-42, and 44-48. Appellants did demonstrate Examiner
error in the rejections of claims 4, 6, 8-12, 14, 16, 31, 32, 36, 37, and 43.

DECISION
We affirm the Examiner’s decision rejecting claims 1-3, 5, 7, 13, 15,
17-30, 33-35, 38-42, and 44-48. We reverse the Examiner’s decision
rejecting claims 4, 6, 8-12, 14, 16, 31, 32, 36, 37, and 43.
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).

AFFIRMED-IN-PART

gvw

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