PTAB

IPR2018-01477

Apple Inc. v. INVT SPE, INC.

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1. Case Identification

2. Patent Overview

  • Title: Communication Apparatus, Communication System and Communication Method
  • Brief Description: The ’439 patent discloses a communication system, such as an Orthogonal Frequency Division Multiplexing (OFDM) system, that uses adaptive modulation and coding (AMC). The invention aims to reduce feedback overhead by combining multiple frequency subbands into "subband groups" and then selecting a single modulation and coding scheme for each entire group based on measured channel quality.

3. Grounds for Unpatentability

Ground 1: Obviousness over Li and Walton - Claims 1, 3, 5-11 are obvious over Li in view of Walton.

  • Prior Art Relied Upon: Li (Patent 6,904,283) and Walton (Patent 7,885,228).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Li teaches the foundational elements of the challenged claims, including an OFDM system where a handset measures channel quality (e.g., SINR) for subcarrier clusters and reports this information to a base station to reduce feedback overhead. Li also discloses partitioning these clusters into pre-defined "groups." However, Petitioner contended that Li suggests deciding modulation/coding parameters for each cluster individually within a group, not for the group as a whole. Walton was argued to supply this missing element by teaching a group-based AMC method that minimizes feedback overhead by calculating an "operating SNR" for a group of channels and then selecting a single transmission mode (modulation and coding parameters) to be "utilized for all of the multiple transmission channels" within that group.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Li and Walton to further the shared, explicit goal of reducing feedback overhead. Li teaches grouping subbands to reduce overhead but stops short of applying a single modulation scheme to the entire group, which still requires significant feedback. Walton explicitly teaches applying a single scheme to a group for the express purpose of reducing the "high feedback rate" associated with channel-by-channel AMC. A POSITA would have recognized that applying Walton's single-scheme-per-group method to Li's system was a straightforward modification to achieve a more efficient reduction in feedback, a key objective of both references.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining the references, as both operate in the same technical field (OFDM-based AMC) and address the same problem (feedback overhead). The proposed modification involved applying a known technique (Walton's group-based parameter selection) to a compatible system (Li's) to achieve predictable improvements.
    • Key Aspects: Petitioner asserted that several claim limitations are met by the combination. For dependent claim 5 (deciding parameters based on the highest classification), Walton's teaching of a zero "back-off factor" when channel variance is zero was argued to result in selecting the highest classification. For dependent claims 6 and 8 (calculating parameters based on a sum of information bits, with claim 8 adding a weight), Walton's "operating SNR" calculation, which uses a "back-off factor" to discount the average SNR based on channel variance, was argued to be a direct analog to weighting the total throughput to prevent overloading lower-quality subbands.

Ground 2: Obviousness over Li, Walton, and Vijayan - Claims 2 and 4 are obvious over Li in view of Walton and in further view of Vijayan.

  • Prior Art Relied Upon: Li (Patent 6,904,283), Walton (Patent 7,885,228), and Vijayan (Patent 7,221,680).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground incorporated the arguments from Ground 1 and addressed the specific subband grouping patterns recited in claims 2 and 4. Petitioner argued that while Li teaches grouping subbands at "predetermined intervals" (i.e., spaced apart), claim 2 requires grouping "neighboring" (contiguous) subbands, and claim 4 requires grouping "all of the subbands." Vijayan was introduced to show that these alternative grouping schemes were well-known and interchangeable options in the art. Vijayan explicitly discloses various grouping methods, including arranging subbands into "consecutive usable subbands" (meeting claim 2) and allocating "all...data subbands" to a user (meeting claim 4).
    • Motivation to Combine: A POSITA would have been motivated to modify the Li/Walton system with the grouping schemes from Vijayan as a matter of simple design choice. Li describes its spaced-grouping method as merely "exemplary," and Vijayan presents contiguous, spaced, and other grouping schemes as known, interchangeable alternatives. A POSITA would have understood that the optimal grouping strategy is implementation-dependent and would have readily substituted Vijayan's contiguous or all-subband grouping into the Li/Walton framework to suit different system requirements, without requiring undue experimentation.
    • Expectation of Success: The combination was asserted to be predictable because it involved substituting one known subband grouping technique for another within a standard OFDM system architecture to achieve the known benefits of different diversity schemes.

4. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-11 of the ’439 patent as unpatentable.