PTAB

IPR2017-00210

Apple Inc v. California Institute Of Technology

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Serial Concatenation of Interleaved Convolutional Codes Forming Turbo-Like Codes
  • Brief Description: The ’710 patent describes methods and systems for error-correcting codes, specifically "irregular repeat-accumulate" (IRA) codes. The disclosed encoder uses a first "outer" coder that irregularly repeats bits, an interleaver that scrambles the repeated bits, and a second "inner" coder that accumulates the bits to generate parity information.

3. Grounds for Unpatentability

Ground 1: Anticipation over Frey - Claims 1 and 3 are anticipated by Frey

  • Prior Art Relied Upon: Frey (B. J. Frey and D. J. C. MacKay, “Irregular Turbocodes,” published on or before March 20, 2000).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Frey taught every limitation of claims 1 and 3. Frey described an encoding method for "irregular turbocodes" which involved: (1) obtaining a block of data; (2) partitioning the data into sub-blocks according to a "degree profile"; (3) a first encoding step that repeated bits in different sub-blocks a different number of times ("irregular repetition"); (4) interleaving the repeated bits using a "permuter"; and (5) a second encoding step using a convolutional encoder. Petitioner contended Frey’s second encoder had a rate of approximately 0.74, which met the "close to one" limitation under its proposed construction.
    • Key Aspects: This ground relied on the petitioner's proposed construction of "close to one" to mean "within 50% of one," which would encompass Frey's disclosed encoder rate of 0.74.

Ground 2: Obviousness over Divsalar and Frey - Claims 1-8 and 11-14 are obvious over Divsalar in view of Frey

  • Prior Art Relied Upon: Divsalar (D. Divsalar et al., “Coding theorems for 'turbo-like' codes," published March 1999) and Frey.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted Divsalar taught a "repeat-accumulate" (RA) code structure that met most limitations of the independent claims. Divsalar’s encoder included a first coder (a regular repeater that duplicates each bit the same number of times), an interleaver, and a second coder (a rate-1 accumulator). The key element missing from Divsalar was the "irregular" repetition taught in the ’710 patent. Petitioner argued that Frey supplied this missing element by explicitly teaching how to construct "irregular turbocodes" where different information bits are repeated a different number of times to improve performance.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references because both addressed the same field of turbo-like error-correcting codes and had highly similar encoder architectures (repeater -> interleaver -> convolutional encoder). Frey demonstrated that introducing irregularity yielded codes with significantly better performance than regular codes. A POSITA would therefore have been motivated to apply Frey’s proven technique of irregular repetition to Divsalar’s regular RA code architecture to achieve the same predictable performance benefits.
    • Expectation of Success: A POSITA would have had a high expectation of success because modifying Divsalar’s regular repeater to be irregular, as taught by Frey, was a simple design change that involved only redistributing connections in the code’s known graphical representation (Tanner graph).

Ground 3: Obviousness over Divsalar, Frey, and Luby97 - Claims 15-17, 19-22, and 24-33 are obvious over Divsalar in view of Frey and further in view of Luby97

  • Prior Art Relied Upon: Divsalar, Frey, and Luby97 (M. Luby et al., “Practical Loss-Resilient Codes,” published in 1997).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Divsalar and Frey to address claims requiring the encoder to receive a "stream of bits" (e.g., claim 15) rather than just a "block." Petitioner argued that while Divsalar and Frey focused on block-based processing, Luby97—a foundational paper on irregular codes—explicitly taught receiving a "stream of data symbols" that is then partitioned into blocks for encoding.
    • Motivation to Combine: A POSITA seeking to apply the block-based Divsalar/Frey encoder to a more practical, continuous data stream would have been motivated to incorporate the well-known teachings of Luby97. Modifying the encoder to handle a stream partitioned into blocks was a conventional and necessary step for real-world application, and Luby97 provided an express roadmap for doing so in the context of irregular codes.
  • Additional Grounds: Petitioner asserted additional obviousness challenges, including that claim 10 was obvious over Divsalar and Frey in view of Pfister (which taught adding a second accumulator to improve performance), and claim 23 was obvious over Divsalar, Frey, and Luby97 in view of Pfister.

4. Key Claim Construction Positions

  • "close to one" (Claims 1 and 3): Petitioner argued this term should be construed to mean "within 50% of one." This construction was based on the patent’s specification, which stated the inner code "can have a rate that is close to one, e.g., within 50%," and the prosecution history, where the Patent Owner amended a claim to recite "a rate within 50% of one" to overcome a rejection, suggesting the original phrase was at least that broad.

5. Key Technical Contentions (Beyond Claim Construction)

  • Irregularity as a Known Improvement Technique: A central technical contention was that by the ’710 patent’s priority date, the concept of "irregularity" was a well-known, conventional technique for improving the performance of error-correcting codes. Petitioner argued that Luby97 first introduced the benefits of irregular codes and that Frey later demonstrated these benefits specifically for turbocodes. Therefore, applying irregularity to any known regular code structure, such as the RA codes in Divsalar, was not an inventive step but rather the obvious application of a known principle to achieve predictable results.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-8, 10-17, and 19-33 of the ’710 patent as unpatentable under 35 U.S.C. §§ 102 and 103.