Apple Inc v. Unwired Planet Intl Ltd

1. Case Identification

• Case #: IPR2020-00642
• Patent #: 9,001,774
• Filed: February 28, 2020
• Petitioner(s): Apple Inc.
• Patent Owner(s): Unwired Planet International Limited
• Challenged Claims: 6-10

2. Patent Overview

• Title: Method for Controlling Downlink Transmissions in a Wireless Network
• Brief Description: The ’774 patent discloses a method for use in a multi-antenna wireless communication system. The method involves receiving a "processing parameter" (which includes at least one of a time delay, phase rotation, and gain) determined from an uplink signal, and then using that parameter along with pilot signals to demodulate data transmitted over two antenna ports.

3. Grounds for Unpatentability

The petition's arguments hinge on the construction of the claim term "at least one of a time delay, a phase rotation and a gain." Petitioner presented two separate obviousness grounds, each based on a different construction of this key term from a co-pending litigation.

Ground 1: Claims 6-10 are obvious over Onggosanusi in view of Kuchi (using Patent Owner's broader construction).

• Prior Art Relied Upon: Onggosanusi (Application # 2002/0114269) and Kuchi (Patent 6,542,556).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that this ground was based on the Patent Owner's proposed disjunctive construction, which requires only one of a time delay, a phase rotation, or a gain. Onggosanusi was asserted to disclose a "processing parameter" in the form of "beamformer weights," which are complex values containing both a magnitude ("gain") and a phase ("phase rotation"). Petitioner contended that Onggosanusi's disclosure of gain and phase rotation, determined from received channel state information (CSI), satisfies the requirements of independent claim 6 under this broad construction. Kuchi was cited primarily to teach that such transmit diversity schemes have practical application in a base station, which would receive an "uplink" signal from a mobile terminal, as recited in the claim.
  • Motivation to Combine: Petitioner argued a POSITA would combine the references because they address the same problem of improving signal reception in multi-antenna wireless systems. A POSITA would be motivated to apply Onggosanusi's method for managing a space-time channel to the practical base station context taught by Kuchi, as it would be a natural and predictable application of the technology.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involves applying Onggosanusi's transmitter and receiver for their intended purpose in a standard cellular system configuration taught by Kuchi, which would be a predictable implementation yielding improved signal diversity.

Ground 2: Claims 6-10 are obvious over Onggosanusi in view of Kuchi (using Petitioner's narrower construction).

• Prior Art Relied Upon: Onggosanusi (Application # 2002/0114269) and Kuchi (Patent 6,542,556).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was based on Petitioner's own proposed conjunctive construction, which requires the processing parameter to include all three elements: at least one time delay, at least one phase rotation, and at least one gain. Petitioner asserted that Onggosanusi's beamformer weights supply the required "gain" and "phase rotation." Kuchi was then relied upon to supply the missing "time delay" element, as Kuchi explicitly discloses using a time delay (e.g., a "2 symbol period delay") for transmit diversity. The combination of Onggosanusi's beamformer weights and Kuchi's time delay thus provides a processing parameter with all three required components, determined based on an uplink signal in the combined system.
  • Motivation to Combine: Petitioner contended that a POSITA would be motivated to modify Onggosanusi's system to include the time delay taught by Kuchi to further improve signal quality. Since gain/phase rotation (from Onggosanusi) and time delay (from Kuchi) are known, complementary techniques for achieving diversity, a POSITA would combine them to enhance performance. Petitioner also noted that Kuchi itself teaches using all three parameters in a transmitter, suggesting the desirability of such a combination.
  • Expectation of Success: A POSITA would expect success in adding Kuchi's time delay function to Onggosanusi's system. The combination involves integrating known diversity techniques with predictable results, and the modification would be straightforward for a person skilled in the art of wireless system design.

4. Key Claim Construction Positions

• The petition's two grounds are explicitly based on competing constructions of the term "at least one of a time delay, a phase rotation and a gain" from claim 6.
  • Patent Owner's Construction (for Ground 1): Petitioner stated the Patent Owner argues for a disjunctive meaning, requiring "at least one of any of the three listed items alone or in some combination," but not necessarily all three.
  • Petitioner's Construction (for Ground 2): Petitioner argued for a conjunctive meaning, requiring "at least one time delay, at least one phase rotation, and at least one gain," submitting that the phrase "at least one of" modifies each category in the conjunctive list that follows.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise its discretion to deny institution under §314(a). Key reasons asserted were:
  • No previous IPR petition had been filed against the ’774 patent by any party, so serial petition concerns under General Plastic were inapplicable.
  • The co-pending district court litigation was in its early stages, with no claim construction ruling issued and fact discovery not yet closed, making an IPR a more efficient forum for resolving the invalidity dispute based on patents and printed publications.
  • The technical subject matter—involving signal processing in multi-antenna wireless systems—is well-suited to the expertise of the PTAB's administrative patent judges.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 6-10 of Patent 9,001,774 as unpatentable.