PTAB

IPR2025-00790

Samsung Electronics Co Ltd v. GenghisComm Holdings LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Transmitting and Receiving Multicarrier Signals
  • Brief Description: The ’508 patent describes methods and systems for wireless communications, particularly for reducing the peak-to-average power ratio (PAPR) in Orthogonal Frequency Division Multiplexing (OFDM) systems. The disclosed technique involves spreading data symbols using codes from a discrete Fourier transform (DFT) before modulation and transmission, creating a single-carrier frequency division multiple access (SC-FDMA) signal.

3. Grounds for Unpatentability

Ground 1: Anticipation and Obviousness over Shattil-537 - Claims 1, 3, 5, 9, 11, 13, 17, 19, and 21 are anticipated by or obvious over Shattil-537.

  • Prior Art Relied Upon: Shattil-537 (International Publication No. WO 02/054537).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shattil-537, which discloses a system using Carrier Interferometry (CI), teaches all limitations of the independent claims. Shattil-537’s use of CI codes derived from a Fourier transform for multicarrier processing is alleged to be the same as the claimed DFT coding. The reference explicitly discloses provisioning selectable "Carrier Spacing" to adapt transceiver operations based on channel characteristics, meeting the selectable subcarrier spacing limitation. Petitioner asserted that Shattil-537’s generation of a "single-carrier signal" via an inverse fast Fourier transform (IFFT) on the DFT-coded symbols corresponds to the claimed generation of an SC-FDMA signal. Finally, Shattil-537 expressly teaches that symbol duration is the inverse of carrier spacing, directly mapping to the claim limitation of providing a symbol period by selecting a subcarrier spacing.
    • Key Aspects: Petitioner contended that the inventor of the ’508 patent is also the inventor of Shattil-537, yet failed to disclose this reference to the USPTO during prosecution.

Ground 2: Obviousness over Shattil-537 in view of Doufexi or Lucent - Claims 2, 4-6, 10, 12-14, 18, and 20-22 are obvious over Shattil-537 in view of Doufexi or, alternatively, Lucent.

  • Prior Art Relied Upon: Shattil-537 (WO 02/054537), Doufexi (a 2002 IEEE paper), and Lucent (a 2002 3GPP contribution).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that while Shattil-537 teaches the core concept of an adaptable system with selectable subcarrier spacings, it lacks specific numerical examples and configurations for different deployment scenarios as recited in the dependent claims. Doufexi and Lucent remedy this deficiency.
      • Doufexi discloses specific selectable subcarrier spacings for a 4G system (e.g., 16 kHz and 8 kHz) to optimize performance across a "wide range of environments." This teaches the limitations of claims 2, 10, and 18 (spacing as a power of two) and claims 4, 12, and 20 (integer multiples of a first spacing).
      • Lucent proposes a baseline OFDM system with three distinct configurations for different environments (Indoor, Vehicular, Pedestrian), each with a specific subcarrier spacing (19.2 kHz, 9.6 kHz, and 4.8 kHz). This directly teaches configuring spacings for different deployment scenarios (claims 5, 13, 21) and providing a different number of symbols per frame based on the chosen spacing (claims 6, 14, 22).
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the adaptable framework of Shattil-537 with the concrete, performance-enhancing configurations from Doufexi and Lucent. Both secondary references explicitly state that a fixed set of parameters is insufficient for modern wireless systems and that dynamically adapting parameters like subcarrier spacing is necessary to achieve superior performance across different environments. This provides a clear motivation to implement the specific spacing schemes of Doufexi or Lucent within the system taught by Shattil-537.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because combining these teachings involves applying known design principles to achieve a predictable improvement in system adaptability and performance. The underlying relationship between subcarrier spacing and orthogonality was well-understood, ensuring the combined system would function as expected.

4. Arguments Regarding Discretionary Denial

  • §314(a) Fintiv Factors: Petitioner argued against discretionary denial under Fintiv, stating that the factors weigh in favor of institution. Petitioner contended it will seek a stay of the co-pending district court litigation. The parallel trial date is scheduled for April 2026, which is after the projected Final Written Decision (FWD) deadline, and its firmness is speculative. The district court case is in its early stages with minimal investment, and Petitioner has stipulated it will not pursue the same invalidity grounds in district court if the IPR is instituted.
  • §325(d) Factors: Petitioner argued that denial under §325(d) is unwarranted. The primary prior art reference, Shattil-537, was never presented to or considered by the Examiner during the prosecution of the ’508 patent, despite its inventor being the same as the inventor of the challenged patent. Therefore, the petition raises issues that the USPTO has not previously had a chance to consider.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 9-14, and 17-22 of Patent 11,223,508 as unpatentable.