PTAB

IPR2023-00964

General Motors LLC v. Neo Wireless LLC

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1. Case Identification

2. Patent Overview

  • Title: Methods and Apparatus for Multi-Carrier Communication Systems with Adaptive Transmission and Feedback
  • Brief Description: The ’941 patent relates to link adaptation techniques in Orthogonal Frequency Division Multiplexing (OFDM) communication systems. The invention purports to improve performance by using a subchannel configuration that is configurable and can be adjusted dynamically based on user profiles or environmental conditions, as opposed to prior art systems with allegedly fixed subchannel configurations.

3. Grounds for Unpatentability

Ground 1: Obviousness over 802.16a and Heath - Claims 1-14 are obvious over 802.16a in view of Heath.

  • Prior Art Relied Upon: 802.16a-2001 and 802.16a-2003 (collectively, "802.16a"), and Heath (Patent 6,937,592).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that 802.16a, an industry standard for wireless metropolitan area networks, disclosed the core elements of the challenged claims. This included an OFDM system where a base station sends control messages (via a Frame Control Header and DL-MAP) to mobile stations, with the messages containing parameters for subsequent data transmission. 802.16a taught using different antenna schemes, including a transmission diversity scheme (Space Time Coding, or STC) and a multi-user Multiple-Input Multiple-Output (MIMO) scheme (Adaptive Antenna System, or AAS). It also disclosed using both localized (adjacent carrier permutation) and distributed (distributed carrier permutation) subcarrier configurations and a mechanism to indicate which configuration to use. Heath was argued to disclose a system that adaptively selects between a transmission diversity scheme and a spatial multiplexing (MIMO) scheme based on channel conditions to optimize performance.
    • Motivation to Combine: A POSITA would combine the teachings of Heath with the 802.16a standard to improve system performance. While 802.16a provided the different antenna schemes (STC and AAS/MIMO), it did not explicitly detail the logic for selecting between them. Petitioner contended a POSITA would look to prior art like Heath to incorporate its mode determination logic, thereby enabling the 802.16a system to intelligently select the most appropriate antenna scheme based on channel conditions, a known method for improving wireless system performance.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involved implementing a known selection strategy (from Heath) into a system (802.16a) that already possessed the functional components to be selected (STC and MIMO modes).

Ground 2: Obviousness over Walton040 and Li017 - Claims 1, 3-8, and 10-14 are obvious over Walton040 in view of Li017.

  • Prior Art Relied Upon: Walton040 (Application # 2003/0125040) and Li017 (Application # 2002/0147017).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Walton040 taught a multi-cell MIMO-OFDM system that adaptively processes data based on Channel State Information (CSI) and communicates parameters like antenna assignments and coding schemes to terminals via a control channel. Walton040 supported various antenna modes, including MISO (for transmit diversity) and MIMO. Li017 was presented as teaching a method for adaptively allocating subcarriers in a multi-cell system to mitigate interference. Li017 specifically disclosed selecting between "coherence clusters" (localized subcarriers) for static users and "diversity clusters" (distributed subcarriers) for mobile users or those near cell edges.
    • Motivation to Combine: A POSITA would combine these references because while Walton040 described a robust MIMO-OFDM system, it did not explicitly teach how to intelligently group or assign subcarriers to different users to handle issues like intercell interference. A POSITA would be motivated to incorporate Li017’s method for selecting subchannel configurations (localized vs. distributed) based on user mobility and location into the Walton040 system. This would address the known problem of interference and improve overall system performance, particularly in the multi-cell environment described by Walton040.
    • Expectation of Success: Success would be expected because the scenarios described in Li017 (mobile users, static users, users near cell edges) are inherent to the multi-cell system of Walton040. Applying Li017's solution would be a predictable improvement.

Ground 3: Obviousness over Walton040, Li017, and Tufvesson - Claims 2 and 9 are obvious over Walton040 in view of Li017 and Tufvesson.

  • Prior Art Relied Upon: Walton040 (Application # 2003/0125040), Li017 (Application # 2002/0147017), and Tufvesson (a 1997 IEEE paper).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon Ground 2 to address the limitation of indicating a "training pilot pattern" (claims 2 and 9). While Walton040 and Li017 relied on pilots for CSI estimation, they did not explicitly teach communicating the specific pilot pattern to the mobile station. Tufvesson was argued to remedy this by teaching that the pilot pattern used for channel estimation must be known to the mobile station and is part of the control information transferred to it.
    • Motivation to Combine: A POSITA implementing the combined Walton040/Li017 system would recognize that for the mobile station to perform CSI estimation, it must know the pilot pattern being used by the base station. Petitioner argued it would be obvious to look to art like Tufvesson and include the training pilot pattern as part of the control channel information. This is a necessary and logical step to make the adaptive features of the underlying system functional.
    • Expectation of Success: The combination would predictably result in a functioning system. Communicating the pilot pattern is a fundamental requirement for pilot-based channel estimation, making its inclusion a straightforward and necessary design choice.

4. Key Claim Construction Positions

  • Petitioner asserted that for the purposes of the petition, no claim terms required explicit construction and that all terms should be given their plain and ordinary meaning.
  • Petitioner noted that the Board, in a prior IPR, determined that the term "mobile station-specific transmission parameters indicate... a corresponding subchannel configuration... characterized by distributed subcarriers or localized subcarriers" requires, at a minimum, that the parameters are capable of indicating both configurations as alternatives. Petitioner argued the prior art meets this interpretation.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued extensively that discretionary denial would be improper under both §314(a) (Fintiv factors) and §325(d) (General Plastic and Advanced Bionics).
  • Fintiv Factors: Petitioner contended the factors favored institution because the parallel district court litigation was in its early stages in a multi-district litigation (MDL) with no trial date set, and Petitioner stipulated it would not pursue the same invalidity grounds at trial if the IPR is instituted.
  • Serial Petitions: Petitioner argued this was not an abusive serial petition because it had not previously challenged the ’941 patent, and a prior IPR filed by a different party (Dell) was based on different prior art combinations and arguments and was denied institution.
  • Previously Presented Art: Petitioner asserted that the art and arguments presented in the petition were new and non-cumulative relative to the art considered by the examiner during prosecution, thus satisfying the Advanced Bionics framework and weighing against denial under §325(d).

6. Relief Requested

  • Petitioner requested that the Board institute an inter partes review and cancel claims 1-14 of the ’941 patent as unpatentable.