PTAB

IPR2015-00243

2Wire Inc v. TQ Delta LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: System and Method for Scrambling the Phase of the Carriers in a Multicarrier Communications System
  • Brief Description: The ’427 patent describes a method for reducing the peak-to-average ratio (PAR) in multicarrier communication systems, such as Discrete Multitone (DMT) systems. The invention involves scrambling the phase of carrier signals by computing and applying a phase shift for each carrier based on a value determined independently of the data bits being transmitted on that carrier.

3. Grounds for Unpatentability

Ground 1: Obviousness over Suzuki/McGregor - Claims 1, 6, 7, and 29 are obvious over Suzuki (’614 patent) in view of Suzuki (’415 patent), the Admitted Prior Art, and McGregor (’100 patent).

  • Prior Art Relied Upon: Suzuki (Patent 5,903,614), Suzuki (Patent 5,694,415), Admitted Prior Art from the ’427 patent, and McGregor (Patent 5,577,100).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Suzuki ’614 disclosed a wireless multicarrier (OFDM) communication system that uses random phase shifts for its subcarriers but did not specify how to generate these random values. Suzuki ’415 allegedly supplied this missing detail by teaching a method for generating phase shifts using a pseudo-random number generator (PRNG) based on an initial value, independent of the modulated data. The Admitted Prior Art was cited to provide the well-known context of multicarrier transceivers. Finally, McGregor was asserted to teach the use of transceivers for transporting applications, such as billing, over a network.
    • Motivation to Combine: A POSITA would combine Suzuki ’415 with Suzuki ’614 because Suzuki ’614’s general disclosure of random phase shifting would have prompted a skilled artisan to look for a known, specific implementation, which Suzuki ’415 provided. The combination would have been a predictable solution. McGregor would be combined to add application functionality to the communication system, a common design goal.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining these references because it involved applying a known PRNG technique (Suzuki ’415) to implement a known concept (random phase shifting in Suzuki ’614) in a predictable manner.

Ground 2: Obviousness over T1.413/Laroia - Claims 1, 6, 7, and 29 are obvious over T1.413 in combination with Laroia (’268 patent) and Suzuki (’415 patent).

  • Prior Art Relied Upon: T1.413 (ANSI ADSL standard, 1998), Laroia (Patent 6,301,268), and Suzuki (Patent 5,694,415).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that T1.413 described the standard for ADSL systems, including the use of DMT transceivers communicating over twisted-wire pairs. Laroia taught methods for reducing PAR in such systems by generating alternative signal sequences and selecting the one with the lower PAR, a process that involved rotating carrier phases based on random assignment. While Laroia suggested random assignment, Suzuki ’415 again provided the specific mechanism for implementing it using a PRNG that could be synchronized between transceivers.
    • Motivation to Combine: A POSITA would be motivated to implement Laroia's PAR-reduction techniques within a standard-compliant ADSL system as described by T1.413 to address the known problem of high PAR. Upon implementing Laroia’s random assignment feature, a POSITA would naturally turn to a known method for generating synchronized random numbers, such as that taught by Suzuki ’415, to complete the system.
    • Expectation of Success: The combination was portrayed as the application of a known PAR-reduction method (Laroia) to a standard communication system (T1.413), using a standard component for implementation (the PRNG from Suzuki ’415), leading to a high expectation of success.

Ground 3: Obviousness over Fifield/McGregor - Claims 1, 6, 7, and 29 are obvious over Fifield (’951 patent) in combination with Suzuki (’415 patent) and McGregor (’100 patent).

  • Prior Art Relied Upon: Fifield (Patent 6,781,951), Suzuki (Patent 5,694,415), and McGregor (Patent 5,577,100).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Fifield taught an OFDM-based radio communication system that randomized the initial phase shifts of carriers to improve signal integrity, explicitly stating this randomization could be done in "a variety of ways known to the person skilled in the art." Petitioner asserted that Suzuki ’415 provided exactly such a well-known way, teaching the use of a PRNG to create phase shifts. McGregor was again used to teach the claimed limitation of transporting one or more applications over the communication system.
    • Motivation to Combine: The motivation was explicit in Fifield itself, which invited the use of known randomization techniques. A POSITA, when implementing Fifield's system, would have found it obvious to use the known PRNG method from Suzuki ’415 as a straightforward design choice. Combining McGregor was argued to be a simple addition of a known feature (application transport) to Fifield's communication system.
    • Expectation of Success: Success was expected because Fifield expressly suggested incorporating a known randomization method, and Suzuki ’415 provided a compatible and well-understood solution.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 6, 7, and 29 of the ’427 patent as unpatentable under 35 U.S.C. §103.