PTAB

IPR2025-01387

Volex PLC v. Credo Technology Group Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Communication Methods, Links, and Transceivers
  • Brief Description: The ’111 patent relates to methods and systems for pre-equalizing high-data-rate communication signals to compensate for channel distortion. The invention involves storing multiple sets of pre-equalizer filter coefficients, where each set corresponds to a different channel model, selecting an appropriate set as initial values, and then adaptively updating these values during a training phase.

3. Grounds for Unpatentability

Ground 1: Claims 1-19 are obvious over Lugthart-706 in view of Das Sharma and Mezer.

  • Prior Art Relied Upon: Lugthart-706 (Patent 9,882,706), Das Sharma (Application # 2014/0281067), and Mezer (Patent 7,239,665).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the prior art combination discloses all limitations of the challenged claims. Lugthart-706 taught an active cable system with transceivers that perform pre-equalization (termed "pre-emphasis") on signals transmitted between a pluggable module and a host device over a chip-to-module (C2M) channel. Das Sharma taught an adaptive pre-equalization process where initial filter coefficients are stored in registers and then updated during a training phase to optimize signal transmission, specifically in the context of high-speed SerDes protocols like PCI Express, which Lugthart-706 supports. Mezer taught pre-computing and storing multiple different sets of initial equalizer coefficients for various channel types ("channel models") and selecting the most suitable set based on the specific channel in use to accelerate the convergence of an adaptive equalization process. Petitioner contended that combining these teachings results in the method of independent claim 1: selecting one of multiple registers corresponding to a different channel model (Mezer), updating the initial coefficients during a training phase (Das Sharma), and using the updated values to transmit data (Lugthart-706). Petitioner further asserted this combination renders obvious the apparatus claims (8, 11, 16) and all dependent claims, which add limitations also taught by the combination, such as applying the method to C2M channels (Lugthart-706) or using performance characteristics like bit error rate (Das Sharma) or error signal energy (Mezer) to select the best coefficient set.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine Lugthart-706 with Das Sharma to implement the well-known technique of adaptive pre-equalization to improve data transmission performance and reduce bit error rate, a clear benefit for the high-speed link in Lugthart-706. A POSA would have been further motivated to incorporate Mezer's teachings to make the adaptive process more efficient. Storing multiple pre-computed coefficient sets for different potential channel models and selecting the best one as a starting point, as taught by Mezer, would shorten the training time and potentially reduce hardware complexity, which were known and desirable goals in the field. This was particularly relevant for a pluggable module like that in Lugthart-706, which could be connected to various host devices with different channel characteristics.
    • Expectation of Success: A POSA would have had a reasonable expectation of success in creating the claimed invention. The combination involved applying known techniques (adaptive equalization, storing initial coefficients, using different coefficient sets for different channels) to a known system (an active cable with C2M links) to achieve predictable results (improved performance and efficiency). All components and methods were well-understood in the art of high-speed digital communications and their integration was a matter of routine engineering.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial would be inappropriate. This petition is substantially the same as a previously filed petition by another party (Amphenol in IPR2025-00699), and Petitioner stated its intention to file a motion to join that proceeding upon institution. Petitioner further argued that a final written decision (FWD) in the co-pending IPR would issue well before the scheduled trial date in the parallel district court litigation (Texas Litigation), and that Petitioner would stipulate not to pursue any ground raised or reasonably available in this IPR in that litigation.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-19 of the ’111 patent as unpatentable under 35 U.S.C. §103.