LG Electronics Inc v. Jawbone Innovations LLC

1. Case Identification

• Case #: IPR2023-01134
• Patent #: 11,122,357
• Filed: June 29, 2023
• Petitioner(s): LG Electronics Inc.
• Patent Owner(s): Jawbone Innovations, LLC
• Challenged Claims: 1-20

2. Patent Overview

• Title: Audio Processing Using Virtual Microphones
• Brief Description: The ’357 patent discloses devices for reducing noise in audio signals captured by a microphone array. The system creates two "virtual" microphones by combining signals from two physical microphones, where one virtual microphone captures a target signal (speech) plus noise, and the other is designed to capture only noise, allowing for subsequent noise cancellation.

3. Grounds for Unpatentability

Ground 1: Claims 1-20 are obvious over Brandstein and Gannot.

• Prior Art Relied Upon: Brandstein (a 2001 reference book, MICROPHONE ARRAYS: SIGNAL PROCESSING TECHNIQUES AND APPLICATIONS) and Gannot (a 2001 article in IEEE TRANSACTIONS ON SIGNAL PROCESSING).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Brandstein taught all fundamental elements of the claims by describing the widely known Generalized Sidelobe Canceler (GSC) for speech enhancement. Brandstein’s GSC created a first virtual microphone (a fixed beamformer) to capture speech plus noise and a second virtual microphone (using a blocking matrix) to capture only noise. These virtual microphones inherently had dissimilar responses to speech but similar responses to noise, allowing noise to be canceled by subtracting the output of the second from the first. To meet the "varying linear transfer function" limitation of claims 1 and 15, Petitioner relied on Gannot. Gannot explicitly disclosed an enhanced GSC that handles arbitrary and time-varying linear transfer functions between microphones to improve performance in complex acoustic environments.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references because Gannot started with the standard GSC framework disclosed in Brandstein and proposed a specific, well-defined modification to improve its robustness. The motivation was to enhance a known noise reduction system to handle more complex, real-world acoustic conditions, a problem Gannot explicitly addressed.
  • Expectation of Success: Gannot not only proposed the modification but also provided the complete underlying algorithm and reported successful results from a real-world implementation. This demonstration of a working system provided a strong expectation of success.

Ground 2: Claims 4, 13, 14, 18, and 19 are obvious over Brandstein and Gannot in view of Griffiths-Jim.

• Prior Art Relied Upon: Brandstein, Gannot, and Griffiths-Jim (a 1982 article in IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an alternative argument for claims reciting signal delays. Petitioner contended that while Brandstein taught a "delay-and-subtract" structure for its GSC blocking matrix, it did not explicitly show the delay elements. Griffiths-Jim, the seminal paper that introduced the GSC, explicitly disclosed using delay elements to time-align sensor signals before subtraction in the blocking matrix. This alignment is necessary to block the target signal effectively when it arrives from an off-perpendicular angle.
  • Motivation to Combine: A POSITA would combine Griffiths-Jim with Brandstein because Brandstein’s discussion of the GSC was based on and cited the original Griffiths-Jim paper. A skilled artisan implementing the system described in Brandstein would naturally refer to the foundational Griffiths-Jim paper for explicit implementation details, such as the required delay elements. This combination represented supplementing a summary with its original source, not combining disparate technologies.

Ground 3: Claims 4, 5, 6, 13, 14, 18, and 19 are obvious over Brandstein and Gannot in view of McCowan.

• Prior Art Relied Upon: Brandstein, Gannot, and McCowan (a 2002 article in DIGITAL SIGNAL PROCESSING).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground provided an alternative basis for claims relating to delays, particularly for near-field sources (claims 5 and 6). Petitioner argued that Brandstein taught that GSC beamforming could be extended from far-field to near-field assumptions. McCowan expressly taught how to achieve this by introducing a "near-field compensation unit" to the standard GSC. This unit time-aligned microphone signals using complex exponential delay terms derived from standard near-field propagation models, directly teaching the limitations of claims 5 and 6.
  • Motivation to Combine: A POSITA would combine McCowan with Brandstein because McCowan addressed a known issue—adapting the standard GSC for near-field conditions, a scenario Brandstein itself contemplated. McCowan provided a direct, successful solution to a known problem within the GSC framework, motivating its integration to improve the system's versatility.
  • Expectation of Success: McCowan explained exactly how to modify the GSC, reported successful results of its implementation, and showed that once near-field compensation was performed, a standard GSC blocking matrix could be used. This provided a clear path to implementation with a high expectation of success.

4. Arguments Regarding Discretionary Denial

• Discretionary Denial under Fintiv: Petitioner argued against discretionary denial under 35 U.S.C. §314(a), asserting that the co-pending district court litigation was in its earliest stages, with no trial date set and minimal investment by the parties. Petitioner noted it would move to stay the litigation and stipulated that, if a stay is denied, it would not pursue the same invalidity grounds in court, thus avoiding duplicative efforts.
• Prior IPR Petitions (General Plastic): Petitioner argued that this petition, filed with a motion for joinder to an already-instituted IPR on the same patent, should not be denied under the General Plastic factors. Petitioner asserted that such "me-too" petitions are generally not subject to denial on these grounds.
• Discretionary Denial under §325(d): Petitioner argued that denial under 35 U.S.C. §325(d) was inappropriate because the prior art references central to all grounds (Brandstein, Gannot, Griffiths-Jim, and McCowan) were never considered by the examiner during the original prosecution of the ’357 patent.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-20 of the ’357 patent as unpatentable.