PTAB

IPR2017-00628

Apple Inc v. Andrea Electronics Corp

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Interference Canceling Method and Apparatus
  • Brief Description: The ’607 patent relates to a system for canceling acoustic echo in teleconferencing systems. The disclosed technology splits a local microphone signal (target signal) and a far-end audio signal (interference signal) into corresponding frequency sub-bands and uses adaptive filters to remove the echo from each sub-band individually before recombining the signal for transmission.

3. Grounds for Unpatentability

Ground 1: Anticipation by Chu - Claims 1 and 25 are anticipated by Chu under 35 U.S.C. §102.

  • Prior Art Relied Upon: Chu (Patent 5,263,019).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Chu teaches an echo canceling system that anticipates every element of independent claims 1 and 25. Chu disclosed a system with inputs for a near-end microphone signal (“target signal”) and a far-end speaker signal (“interference signal”). Petitioner asserted that Chu’s signal splitters (elements 16 and 30) perform the function of the claimed “beam splitter” by separating both the target and interference signals into a plurality of corresponding, frequency-limited bands. Furthermore, Chu’s echo canceller bank (element 18) was argued to be an adaptive filter that estimates and subtracts the echo from each corresponding band, thus meeting the final limitation of the challenged claims.
    • Key Aspects: Petitioner contended that the overall scheme for sub-band echo cancellation depicted in Figure 1 of Chu is “effectively indistinguishable” from the system claimed in the ’607 patent.

Ground 2: Obviousness over Chu and Kellermann - Claims 1 and 25 are obvious over Chu in view of Kellermann under 35 U.S.C. §103.

  • Prior Art Relied Upon: Chu (Patent 5,263,019) and Kellermann (a 1997 IEEE publication titled "Strategies for Combining Acoustic Echo Cancellation and Adaptive Beamforming Microphone Arrays").
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative in the event the claims were construed to require a “beam” formed by a microphone array—a feature Petitioner argued Chu does not explicitly disclose. Petitioner asserted that Kellermann supplies this teaching, as it describes the benefits of replacing a single microphone with an adaptive beamforming microphone array to improve echo cancellation in teleconferencing applications. The combination of Chu’s sub-band processing architecture with Kellermann’s advanced beamforming input would, Petitioner argued, result in the claimed invention.
    • Motivation to Combine: A POSITA would combine the teachings of Chu and Kellermann because both references address the identical problem of acoustic echo in hands-free teleconferencing using the same core technology of adaptive filtering. Kellermann explicitly suggested using a microphone array to solve known challenges such as multiple speakers in a room, a scenario that Chu’s conferencing system was designed to handle. This provided a clear reason to enhance Chu’s system with Kellermann’s well-understood microphone array technology for improved performance.
    • Expectation of Success: Petitioner argued that integrating a beamforming microphone array into Chu's system represented a routine engineering design choice. Because Kellermann provided extensive guidance on the implementation and predictable benefits of its microphone arrays, a POSITA would have had a high expectation of success in making this modification.

4. Key Claim Construction Positions

  • "target signal": Petitioner proposed the construction "a signal containing signals from a target source and an interference source." This construction was argued to be consistent with the ’607 patent’s specification, which describes the signal input for processing (termed a "beam signal") as containing both desired speech from the near-end and the undesired echo (interference).
  • "interference signal": The proposed construction was "a signal from the far end, or a signal representing the echo generated by the broadcast of the far end signal." Petitioner based this on the specification’s disclosure that the "far end signal" is used as the reference input to the adaptive filters to estimate and cancel the echo from the target signal.
  • "beam splitter": Petitioner proposed construing this term as "hardware or software for dividing the target signal into band-limited components... and for dividing the interference signal into band-limited components." This broader construction was advanced to argue that the term is not limited to splitting a "beam" from a microphone array but applies to any signal splitter, consistent with figures in the ’607 patent that show splitters acting on both the microphone signal and the far-end signal.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1 and 25 of Patent 6,049,607 as unpatentable.