Qualcomm Inc v. UNM Rainforest Innovations

1. Case Identification

• Case #: IPR2021-00377
• Patent #: 8,249,204
• Filed: December 28, 2020
• Petitioner(s): Qualcomm Inc
• Patent Owner(s): UNM Rainforest Innovations
• Challenged Claims: 1, 2, 11-13

2. Patent Overview

• Title: Providing Channel State Information Feedback in Wireless Communication Systems
• Brief Description: The ’204 patent discloses a method for a mobile station in a wireless system to provide feedback to a base station. The method involves calculating channel responses for multiple communication channels, selecting a plurality of "channel taps" (samples) from each response to estimate channel state information (CSI), compressing the estimated CSI, and sending the compressed feedback to the base station for use in adapting future transmissions.

3. Grounds for Unpatentability

Ground 1: Obviousness over Hui - Claims 1, 2, and 11-13

• Prior Art Relied Upon: Hui (Patent 8,213,368).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Hui, which was not considered during prosecution, disclosed every limitation of the challenged claims. Hui described an adaptive CSI compression technique in a MIMO system where a mobile station calculates an "estimated channel response" for each communication channel. Crucially, Petitioner asserted that Hui taught the key limitation of "selecting a plurality of channel taps" by disclosing that each channel response is associated with a filter having "Q non-zero tap coefficients." The mobile station then compresses information about these tap coefficients (CSI) via quantization and transmits the compressed data to the base station.
  • Motivation to Combine (for §103 grounds): As an alternative to anticipation, Petitioner argued it would have been obvious to select a subset of available channel taps as taught by Hui. A POSITA would have been motivated to select only the "more significant" taps or truncate the time-domain response to reduce the amount of feedback information, thereby conserving bandwidth, a known problem acknowledged in Hui.
  • Expectation of Success (for §103 grounds): A POSITA would have reasonably expected success because selecting more significant taps would predictably result in CSI with reasonable accuracy while reducing bandwidth consumption.

Ground 2: Obviousness over Döttling - Claims 1, 2, and 11-13

• Prior Art Relied Upon: Döttling (EP Application # 1 760 925).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that Döttling disclosed a method for efficient compression of complete CSI in a MIMO system. Döttling’s user terminal calculated a "channel impulse response" and then explicitly "identified the most significant channel taps" from that response. Information corresponding to these selected taps, including complex coefficients and delay information, was then compressed and transmitted to the base station. Petitioner asserted this directly teaches the key limitation of selecting a plurality of taps from a calculated channel response to estimate CSI, which was the basis for allowance of the ’204 patent.
  • Motivation to Combine (for §103 grounds): Döttling described its techniques in the context of a single channel but noted their applicability to MIMO scenarios. Petitioner argued a POSITA would have been motivated to apply Döttling’s efficient, tap-selection-based CSI feedback method to each of the multiple channels in a MIMO system to gain the known benefits of improved data rates and reliability associated with MIMO technology.
  • Expectation of Success (for §103 grounds): A POSITA would have expected success in applying the technique to multiple channels, as it was a parallel application of a known compression technique to improve a known system (MIMO) in a predictable manner.

Ground 3: Obviousness over Hui in view of Maltsev - Claims 1, 2, and 11-13

• Prior Art Relied Upon: Hui (Patent 8,213,368) and Maltsev (Application # 2006/0114816).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground was presented as an alternative in case Hui was found not to explicitly teach selecting a subset of channel taps. Hui provided the primary framework of a MIMO system calculating channel responses comprised of taps and sending compressed CSI feedback. Maltsev was introduced for its explicit teaching that a mobile station can "select[] the most significant predetermined number of rays [i.e., taps] from the estimated sampled channel response."
  • Motivation to Combine (for §103 grounds): A POSITA would combine Maltsev’s teaching of selecting only the most significant taps with Hui’s system to solve the known problem of excessive bandwidth consumption from CSI feedback. Maltsev explicitly stated that selecting significant rays reduces both the processing required by the mobile station and bandwidth consumption, providing a clear reason to modify Hui’s system.
  • Expectation of Success (for §103 grounds): The combination would have yielded the predictable result of a more efficient CSI feedback mechanism, as Hui already contemplated that an estimated channel response could be a subset of total possible taps, ensuring compatibility with Maltsev’s selection technique.

• Additional Grounds: Petitioner asserted additional challenges, including that claims are anticipated by Döttling and Koorapaty (Application # 2006/0018389), obvious over Döttling in view of Maltsev, obvious over Koorapaty alone, and obvious over Koorapaty in view of the general knowledge of a POSA.

4. Key Claim Construction Positions

• "channel responses": Petitioner argued this term should be construed as "communication channels' responses in the time domain to transmitted signals," consistent with a construction from related district court litigation.
• "a plurality of channel taps": Petitioner argued this term should be construed as "at least two samples of a channel response at different time delays," also consistent with the related litigation.
• "channel state information (CSI)": Petitioner proposed construing this term as "information regarding the communication channels between the base station and the mobile station," based on an express definition provided in the ’204 patent’s specification.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that the Board should not exercise its discretion to deny institution under 35 U.S.C. §314(a) based on the Fintiv factors. Petitioner contended that the factors weighed in favor of institution because: (1) the trial date in a parallel district court case involving a customer (Dell) was uncertain and likely to slip; (2) there had been minimal investment in the parallel litigation, which was in its early stages; (3) the invalidity grounds in the IPR petition were different from those in the litigation; and (4) Petitioner is not a party to the parallel litigation. Petitioner also noted it filed a motion to join a previously filed IPR by Intel, mitigating concerns of serial petitions.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 2, and 11-13 of the ’204 patent as unpatentable.