Apple Inc v. Saint Lawrence Communications LLC

1. Case Identification

• Case #: IPR2017-01077
• Patent #: 7,260,521
• Filed: March 13, 2017
• Petitioner(s): Apple Inc.
• Patent Owner(s): Saint Lawrence Communications LLC
• Challenged Claims: 1, 2, 5-8, 10, 11, 14, 15, 17, 28, 29, 32, 33, 35, 37, 38, 41, 42, 44, 55, 56, 59, 60, and 62

2. Patent Overview

• Title: Pitch Prediction of a Synthesized Speech Signal
• Brief Description: The ’521 patent discloses a method and device for reducing pitch prediction error in a Code Excited Linear Prediction (CELP) speech encoder. The invention uses multiple signal paths, each with a different frequency shaping filter, to test pitch codebook parameters, calculates a prediction error for each path, and selects the parameters from the path with the lowest error.

3. Grounds for Unpatentability

Ground 1: Anticipation over Qian - Claims 1, 2, 8, 55, 56, and 62 are anticipated under 35 U.S.C. § 102 over Qian.

• Prior Art Relied Upon: Qian ("Pseudo-Multi-Tap Pitch Filters in a Low Bit-Rate Speech Coder," a 1994 journal article).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Qian discloses every element of the challenged independent claims. Qian described a CELP coder with a "switching configuration" that uses two distinct signal paths to select a pitch filter that "performs the best." One path used a pseudo-multi-tap filter (providing spectral shaping, akin to the ’521 patent’s filtering), while the other used a one-tap filter (providing no spectral shaping, a "constant envelope"). Petitioner asserted Qian’s system calculates a pitch prediction error for each path and selects the one with the higher "predictor gain," which corresponds to the lowest prediction error, thus teaching the claimed selector. Qian’s one-tap filter path meets the limitation of claim 2 requiring a path with "no filter."

Ground 2: Obviousness over Qian and GSM 6.60 - Claims 5, 6, 7, 59, and 60 are obvious over Qian in view of GSM 6.60.

• Prior Art Relied Upon: Qian (1994 journal article) and GSM 6.60 (European Telecommunication Standard, 1997).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that dependent claims 5, 6, 7, 59, and 60 add limitations common to industry-standard CELP coding not explicitly detailed in Qian, which focused on the pitch filter stage. These limitations include using a convolution unit, a pitch gain calculator, and an amplifier. Petitioner asserted that GSM 6.60, an industry standard describing a complete CELP encoder, explicitly teaches these well-known components, such as convolving the past excitation (pitch codevector) with a weighted synthesis impulse response signal (h(n)) and calculating the pitch gain based on the target signal and the convolved codevector.
  • Motivation to Combine: A POSITA seeking to implement Qian's pitch filter improvements would have been motivated to look to a well-known, complete CELP standard like GSM 6.60 for implementation details of the surrounding components. Qian suggests its improvements apply to standard CELP encoders, and GSM 6.60 was a prominent public standard at the time.
  • Expectation of Success: A POSITA would have reasonably expected success in substituting the single pitch filter of GSM 6.60 with the superior switching multi-path configuration from Qian, as it was a predictable integration of a known improvement into a standard architecture.

Ground 3: Obviousness over Qian, Ordentlich, and GSM 6.60 - Claims 10, 11, 14, 15, 17, 28, 29, 32, 33, 35, 37, 38, 41, 42, and 44 are obvious over Qian in view of Ordentlich and in further view of GSM 6.60.

• Prior Art Relied Upon: Qian (1994 journal article), Ordentlich (Patent 5,235,669), and GSM 6.60 (1997 standard).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground targets claims related to an encoder for a "wideband input signal." While Qian and GSM 6.60 describe narrowband CELP systems, Ordentlich explicitly teaches how to adapt existing CELP techniques for wideband speech. Ordentlich addresses the specific problem of modifying the noise weighting filter to handle the different spectral tilt of wideband signals. Petitioner argued that combining the multi-path pitch analysis from Qian with the standard CELP framework of GSM 6.60, and then modifying that combination for wideband use as taught by Ordentlich, renders the wideband-specific claims obvious.
  • Motivation to Combine: A POSITA designing a wideband speech encoder would have sought to adapt well-known, efficient narrowband techniques to minimize the quality and bit-rate tradeoff inherent in wideband coding. Ordentlich provides an explicit motivation and roadmap for adapting systems like those described in Qian and GSM 6.60 for wideband signals, addressing a known problem in the art.
  • Expectation of Success: The combination was presented as a straightforward application of known solutions to known problems. A POSITA would have expected that applying Ordentlich's wideband adaptation techniques to a state-of-the-art narrowband encoder (based on Qian and GSM 6.60) would predictably result in a functional wideband encoder.

4. Key Claim Construction Positions

• "filter for filtering": Petitioner proposed this term should be construed to mean a "frequency shaping filter." This construction is based on the ’521 patent’s specification, which describes using "frequency shaping filters" to compute filtered versions of a codevector and then selecting the filter that minimizes prediction error.
• "pitch codebook": Petitioner argued this term is synonymous with "past excitation" and "adaptive codebook," as the ’521 patent uses these terms interchangeably. The specification explains that the "pitch contribution can be seen as a pitch codebook containing the past excitation signal."
• Means-Plus-Function Terms: For numerous means-plus-function limitations (e.g., in claims 6, 8, and 10), Petitioner adopted constructions previously issued by the U.S. District Court for the Eastern District of Texas in a related litigation, identifying specific processors and algorithms from the specification as the corresponding structure.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. § 325(d) would be inappropriate. The petition asserted that it presented different prior art and arguments than those in two previously filed IPRs against the ’521 patent (IPR2016-00705 and IPR2015-01875). Petitioner noted that Apple Inc. was not a real party-in-interest in those prior cases and that this petition relies on Qian for its primary anticipation challenge, whereas the prior petitions relied on a different reference (Ozawa).

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 2, 5-8, 10, 11, 14, 15, 17, 28, 29, 32, 33, 35, 37, 38, 41, 42, 44, 55, 56, 59, 60, and 62 of the ’521 patent as unpatentable.