PTAB

IPR2019-00959

Apple Inc v. Invt SPE LLC

Log In
Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Communication Apparatus and Subband Group Combination Method
  • Brief Description: The ’439 patent describes a method for adaptive modulation and coding (AMC) in Orthogonal Frequency Division Multiplexing (OFDM) wireless communication systems. The invention purports to reduce feedback overhead by grouping multiple "subbands" (bundles of subcarriers) into larger "subband groups" and applying a single, joint modulation and coding parameter to each entire group.

3. Grounds for Unpatentability

Ground 1: Claim 8 is obvious over Li in view of Vijayan, Hashem, and Cioffi.

  • Prior Art Relied Upon: Li (Patent 6,904,283), Vijayan (Patent 7,221,680), Hashem (Patent 6,721,569), and Cioffi (Patent 5,596,604).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of references taught every limitation of claim 8. Li was asserted to disclose the basic framework of a communication apparatus (a "subscriber" or UE) that performs channel estimation per "cluster" (subband), groups these clusters, decides modulation/coding parameters for a group based on the estimation, and transmits this parameter information back to a base station (BS). Vijayan was argued to teach applying a joint modulation and coding scheme to an entire group of subbands (a "subband group"), a more efficient approach than Li's. Hashem was introduced for its teaching that signaling overhead can be further reduced if the UE itself calculates the optimum transmission parameters ("Link Mode") and sends back a simple index, rather than having the BS perform the calculation. Finally, Petitioner asserted Cioffi taught applying a "weighting factor" to subchannels to account for factors beyond signal-to-noise ratio (SNR), such as interference, when allocating information bits. The combination, Petitioner argued, rendered it obvious to create a UE that estimates channels per subband (Li), decides a joint modulation/coding parameter for an entire subband group (Vijayan), where the decision is made at the UE to save overhead (Hashem), transmits that parameter to a BS (Li, Hashem), receives data encoded using that group-wide parameter (Li, Vijayan), and applies a weighting factor to the group when deciding coding parameters (Cioffi).
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA) would have been motivated to combine the references to solve the well-known problem of reducing feedback overhead and improving spectral efficiency in OFDM systems. A POSITA would combine Li's grouping concept with Vijayan's more efficient joint coding scheme for groups to reduce overhead. Adding Hashem's teaching to have the UE decide the parameters would be a known technique to further minimize signaling. Finally, a POSITA would integrate Cioffi's weighting method to improve the robustness of the link adaptation in the Li/Vijayan system by accounting for real-world factors like interference, a known issue in cellular networks.
    • Expectation of Success: All references operate in the same technical field of OFDM communication and address interrelated problems of channel estimation, adaptive coding, and overhead reduction. Petitioner asserted that combining these known techniques to achieve their predictable benefits would have been straightforward for a POSITA with a reasonable expectation of success.

4. Key Claim Construction Positions

  • "subband" (claim 8): Petitioner proposed this term means "a group of subcarriers in neighboring positions on the frequency domain," based on the patent's specification.
  • "pattern storage section" (claim 8): Petitioner proposed this term means "a memory for storing patterns for selecting subbands." This construction was argued to be central because the prosecution history indicated this was a distinguishing feature over other art.
  • "patterns for selecting subbands" (claim 8): Petitioner proposed this term means "particular configurations or arrangements of subbands on the frequency and/or time domains."

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claim 8 of the ’439 patent as unpatentable.