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TQ Delta, LLC v. Cisco Sys.

United States Court of Appeals for the Federal Circuit

November 22, 2019, Decided

2018-1766, 2018-1767

Opinion

 [*1354]  Stoll, Circuit Judge.

In a pair of inter partes review proceedings, the Patent Trial and Appeal Board invalidated all claims of two related patents. TQ Delta, LLC, the [**2]  patent owner, appeals the Board's determination that all  [*1355]  claims of the challenged patents would have been obvious in view of the prior art asserted by Cisco Systems, Inc., and the other appellees (collectively, "Cisco"). TQ Delta also raises several other challenges to the IPR proceedings relating to the admissibility of evidence, claim construction, and due process. Because fact findings underlying the Board's obviousness determinations are not supported by substantial evidence, we reverse the Board's decisions on that ground.

Background

This is a consolidated appeal from the final written decisions in a pair of IPRs, IPR2016-01020 and IPR2016-01021,1 in which the Board invalidated all claims of two related patents, U.S. Patent Nos. 9,014,243 and 8,718,158, respectively. The Board held each claim unpatentable as obvious in view of various prior art combinations that include the two references at issue on appeal, U.S. Patent Nos. 6,144,696 (Shively) and 6,625,219 (Stopler).

The challenged patents relate to certain improvements to electronic communications systems that lower the peak-to-average power ratio (PAR) of the transmitted signals. PAR is the ratio of the maximum value of a parameter (e.g., voltage) to the time-averaged value of that parameter. [**3]  Lowering the PAR of a communications system is desirable because it reduces power consumption and the likelihood of transmission errors.

The challenged patents specifically address a PAR problem that arises in the transmission of digital data using multicarrier communications systems, such as digital subscriber line (DSL) systems. See, e.g., '243 patent col. 3 ll. 25-37.2 In a multicarrier communications system, multiple bits are transmitted simultaneously across a series of narrow frequency bands called "carriers" in an approach known as "Discrete Multitone Modulation" (DMT). See id. at col. 1 ll. 33-47. Each carrier is independently modulated in accordance with its assigned bit, and the carriers are then combined into a single multicarrier signal for transmission of the data. See id.

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942 F.3d 1352 *; 2019 U.S. App. LEXIS 34865 **; 2019 WL 6222844

TQ DELTA, LLC, Appellant v. CISCO SYSTEMS, INC., DISH NETWORK LLC, COMCAST CABLE COMMUNICATIONS, LLC, COX COMMUNICATIONS, INC., TIME WARNER CABLE ENTERPRISES LLC, VERIZON SERVICES CORP., ARRIS GROUP, INC., Appellees

Prior History:  [**1] Appeals from the United States Patent and Trademark Office, Patent Trial and Appeal Board in Nos. IPR2016-01020, IPR2016-01021, IPR2017-00254, IPR2017-00255, IPR2017-00417, IPR2017-00418.

Disposition: REVERSED.

CORE TERMS

combine, phase, carriers, patents, prior art, skill, references, transmission, invention, conclusory, signal, expert testimony, substantial evidence, scrambling, bits, ordinary person, motivation, determinations, declaration, invalidated, transmitted, multicarrier, subcarriers, disclosure, randomize, scrambler, symbols, conclusory statement, written decision, factfinding

Patent Law, Nonobviousness, Evidence, Fact & Law Issues, Jurisdiction & Review, Standards of Review, Substantial Evidence, Elements & Tests, Prior Art, Administrative Law, Judicial Review, Standards of Review, Evidence