PTAB

IPR2018-01555

HTC Corp v. Invt SPE Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Communication Apparatus and Adaptive Modulation and Coding Method
  • Brief Description: The ’439 patent describes a communication apparatus for Orthogonal Frequency Division Multiplexing (OFDM) wireless systems. The technology aims to reduce feedback signaling overhead by grouping multiple frequency subbands into "subband groups" and then selecting a single, joint set of modulation and coding parameters for each entire group based on pre-stored combination patterns.

3. Grounds for Unpatentability

Ground 1: Claims 1-7 are obvious over Li in view of Vijayan and Hashem.

  • Prior Art Relied Upon: Li (Patent 6,904,283), Vijayan (Patent 7,221,680), and Hashem (Patent 6,721,569).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the claimed invention is an obvious combination of known elements from three contemporaneous references addressing the same technical problem of reducing feedback overhead in OFDM systems.
      • Li was asserted to teach the foundational system: a user device ("subscriber") that performs channel estimation per subband ("cluster"), groups these clusters into "cluster groups" (the claimed "subband groups") based on predefined patterns, and decides corresponding modulation/coding parameters to reduce feedback.
      • Vijayan was asserted to teach the key improvement of applying a single joint modulation and a joint coding parameter to an entire group of subbands, which further reduces signaling overhead compared to assigning parameters to individual subbands within a group.
      • Hashem was asserted to teach that signaling overhead can be further reduced if the user device—rather than the base station—calculates the optimal modulation and coding parameters (a "Link Mode") and transmits only an index representing those parameters back to the base station.
      • Petitioner contended that combining these teachings renders independent claims 1 (the communication apparatus) and 7 (the base station) obvious. Li provides the framework, Vijayan provides the joint parameter assignment for the group, and Hashem provides the rationale for having the user device perform the calculation.
      • Dependent claims 2-4 were argued to be obvious because Li and Vijayan explicitly teach the claimed subband grouping patterns: grouping neighboring subbands (claim 2, taught by Vijayan), grouping subbands at predetermined intervals (claim 3, taught by Li), and grouping all subbands in a time domain (claim 4, taught by Vijayan).
      • Dependent claims 5 and 6 were argued to be obvious design choices. A person of ordinary skill in the art (POSITA) would know to select the modulation scheme with the highest classification (claim 5) when channel conditions are excellent and to select coding parameters that do not exceed the maximum bit rate of the channel (claim 6), as these are fundamental principles of adaptive modulation and coding taught by Li and Vijayan.
    • Motivation to Combine: A POSITA would combine these references to achieve the well-understood and explicitly stated goal of reducing feedback overhead. Li and Vijayan both address this problem through different grouping and parameter assignment strategies. A POSITA would combine Vijayan’s more efficient joint-parameter approach with Li’s grouping framework to achieve a predictable improvement. Further, because Hashem explicitly teaches the overhead-saving benefits of moving the parameter calculation to the user device, a POSITA would be motivated to apply that teaching to the Li/Vijayan system for the same reason.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in making this combination. The proposal involved applying known techniques (joint parameters, UE-based calculation) from one OFDM system to another (Li’s grouping framework) to achieve the predictable result of improved signaling efficiency, a known trade-off in the art.

4. Key Claim Construction Positions

  • Petitioner proposed constructions for several terms central to its obviousness arguments, asserting they should be given their plain and ordinary meaning consistent with the specification.
    • "subband" (claims 1-6): Proposed as "a group of subcarriers in neighboring positions on the frequency domain." This construction was used to equate the "clusters" in Li with the claimed "subbands."
    • "pattern storage section" (claim 1): Proposed as "a memory for storing patterns for selecting subbands." Petitioner argued a POSITA would understand this to be a computer memory, which is necessary for the user device and base station to coordinate the selection of subband groups according to the patterns disclosed in Li and Vijayan.
    • "patterns for selecting subbands" (claim 1): Proposed as "particular configurations or arrangements of subbands on the frequency and/or time domains." This construction was used to map the grouping diagrams in both Li (e.g., selecting every fourth cluster) and Vijayan (e.g., rectangular slot assignments) to the claimed patterns.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-7 of the ’439 patent as unpatentable.