Ex Parte Hudson

Board of Patent Appeals and Interferences

Dec 20, 2006

09849927 (B.P.A.I. Dec. 20, 2006)

The opinion in support of the decision being entered today was not
written for publication and is not binding precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE

__________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________

Ex parte JOHN E. HUDSON
__________

Appeal No. 2006-3367
Application No. 09/849,927
__________

ON BRIEF
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Before HAIRSTON, KRASS, and JERRY SMITH, Administrative Patent Judges.

HAIRSTON, Administrative Patent Judge.

This is an appeal from the final rejection of claims 1 through 4, 6 through 21, and
23 through 29.
The disclosed invention relates to a method and system for equalizing a data
stream generated from a plurality of space time coded (STC) data streams, and received
from a plurality of transmit antenna elements.
Claim 1 is illustrative of the claimed invention, and it reads as follows:
1. A method of channel equalisation comprising:
receiving a data stream generated from a plurality of space time coded
(STC) data streams received from a plurality of transmit antenna elements;
generating via a fast transform a packet spectrum of at least a portion of
the data stream, the packet spectrum being a transform domain representation;
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Application No. 09/849,927

receiving a training sequence for a channel through which the data stream
has been sent and assessing a channel impulse response for the channel based on
the training sequence;
generating via a fast transform a channel impulse response spectrum in the
transform domain for the channel impulse response;
equalising the packet spectrum with the channel impulse response
spectrum to produce an equalised packet spectrum in the transform domain; and
converting the equalised packet spectrum into time domain equalised data
for recovery of information.

The references relied on by the examiner are:
DiToro 4,058,713 Nov. 15, 1977
Perreault 4,141,072 Feb. 20, 1979
Yen et al. (Yen) 4,707,841 Nov. 17, 1987

Claims 1, 2, 4, 6, through 16, 19 through 21, 23 through 27, and 29 stands
rejected under 35 U.S.C. 103(a) as being unpatentable over appellant’s admitted prior art
in view of DiToro.
Claims 3 and 28 stand rejected under 35 U.S.C. § 103(a) as being unpatentable
over appellant’s admitted prior art in view of DiToro and Perreault.
Claims 17 and 18 stand rejected under 35 U.S.C. § 103(a) as being unpatentable
over appellant’s admitted prior art in view of DiToro and Yen.
Reference is made to the briefs and the answer for the respective positions of the
appellant and the examiner.
OPINION
We have carefully considered the entire record before us, and we will reverse the
obviousness rejections of claims 1 through 4, 6 through 21, and 23 through 29.
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Application No. 09/849,927

According to the examiner (answer, pages 3 and 4), the admitted prior art
(specification, page 2, line 30 through page 4, line 12 and page 7, lines 4 through 16)
discloses the claim 1 steps of “receiving a data stream generated from a plurality of space
time coded (STC) data streams received from a plurality of transmit antenna elements,”
and “receiving a training sequence for a channel through which the data stream has been
sent and assessing a channel impulse response for the channel based on the training
sequence.” The examiner acknowledges (answer, page 4) that the remainder of the steps
set forth in claim 1 is not disclosed in the admitted prior art.
The examiner is of the opinion (answer, pages 4 and 5) that DiToro describes the
steps missing in the teachings of the admitted prior art. Based upon the teachings of
DiToro, the examiner concludes (answer, page 5) that “it would have been obvious to one
of ordinary skill in the art at the time of the invention that DiToro teaches an equalization
process implemented in the frequency domain and this is implemented in the receiver as
described in the communication system as described in the AAPA [applicant’s admitted
prior art] so as to accurately recover the transmitted signal in the receiver by minimizing
the computational complexity of the equalization process.”
DiToro describes a process of equalization of received signals by apparatus
operating in the frequency domain (column 1, lines 1 through 10). DiToro transmits a
message signal in burst form, and interleaves known test signals during time gaps in the
message signal (Figure 1C; Abstract; column 2, lines 7 through 28). At the receiver, the
message signal and the known test signal are converted into the frequency domain
(Abstract; column 2, lines 29 and 30). DiToro makes clear that the message signal and
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Application No. 09/849,927

the known test signals are transmitted via the single antenna 22 (Figure 2; column 5, lines
25 through 28; column 11, lines 13 through 19).
Appellant argues (brief, page 7) that the skilled artisan would not modify the
appellant’s admitted prior art “which utilizes STC in a non-dispersive communications
channel with the equalization method disclosed in DiToro” because “[t]he equalization
method of DiToro is applicable to a single, partitioned signal transmission over a
dispersive communications channel in which time gaps must be inserted between
message frames and test signals.” Appellant also argues (brief, page 7) that “a skilled
person would not find motivation in DiToro to modify the AAPA using the arrangement
disclosed in DiToro to arrive at the method of the present invention in view of the
inability to insert effective time gaps into the plurality of STC data streams to prevent
overlapping at the receiver.” Appellant concludes (answer, page 8) that it is only possible
to arrive at the method of the present invention through the impermissible use of
hindsight.
We agree with appellant’s arguments. The examiner’s reasoning never points out
how the skilled artisan is to combine the disparate teachings of the appellant’s admitted
prior art and the teachings of DiToro. Even if we assume for the sake of argument that
the skilled artisan would have found it obvious to combine the teachings, we still find that
the steps outlined in the claims on appeal would not be found in the combined teachings.
Thus, the obviousness rejection of claims 1, 2, 4, 6 through 14, 19 through 21, 23 through
27, and 29 is reversed because we agree with the appellant’s argument that the examiner
has resorted to impermissible hindsight to establish the obviousness of the claimed
invention.
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Application No. 09/849,927

The obviousness rejections of claims 3, 17, 18, and 28 are reversed because the
teachings of Perreault and Yen fail to cure the noted shortcomings in the teachings of the
admitted prior art and DiToro.
DECISION
The decision of the examiner rejecting claims 1 through 4, 6 through 21, and 23
through 29 under 35 U.S.C. § 103(a) is reversed.

REVERSED
)
Kenneth W. Hairston )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
Errol A. Krass )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
Jerry Smith )
Administrative Patent Judge )

KWH/eld
Appeal No. 2006-3367 Page 6
Application No. 09/849,927

William M. Lee, Jr.
Lee, Mann, Smith, McWilliams, Sweeney & Ohlson
P.O. Box 2786
Chicago IL 60690-2786