PTAB

IPR2025-00899

Samsung Electronics Co Ltd v. GenghisComm Holdings LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Receiving a Signal in a Wireless Network
  • Brief Description: The ’386 patent relates to methods and apparatus for receiving Orthogonal Frequency Division Multiplexing (OFDM) signals in a wireless network. The technology focuses on reducing high peak-to-average power ratios (PAPR) by shaping an OFDM signal into a superposition of cyclic-shifted pulse waveforms using complex-valued codes.

3. Grounds for Unpatentability

Ground 1: Anticipation and Obviousness over Shattil - Claims 1-3, 5-8, 10-12, 14-17, 19-21, and 23-26 are anticipated by or obvious over Shattil.

  • Prior Art Relied Upon: Shattil (International Publication No. WO 02/054537).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Shattil, which teaches "Carrier Interferometry" (CI) techniques applicable to multicarrier systems like OFDM, discloses every limitation of the challenged claims. Shattil described a receiver that processes OFDM signals by converting them to the frequency domain using an FFT processor. It explicitly taught decoding CI-coded symbols by correlating the received signal with an inverse or complex-conjugate of the transmit-side codes, which were derived from a Fourier transform. Petitioner contended this directly maps to the claim limitations of receiving an OFDM signal, converting it to frequency-domain values, and decoding those values using codes that are inverse to, or complex-conjugate of, the codes used for shaping the signal.
    • Motivation to Combine (for §103 grounds): For the alternative obviousness ground, Petitioner asserted that because Shattil explicitly stated its CI techniques could be applied to OFDM systems, a POSITA would have been motivated to implement Shattil’s disclosed methods in a standard OFDM receiver to manage signal characteristics.
    • Expectation of Success (for §103 grounds): A POSITA would have a high expectation of success, as Shattil taught the direct application of its CI coding and decoding processes to OFDM protocols.

Ground 2: Obviousness over Galda and Brüninghaus - Claims 1 and 6-8 are obvious over Galda in view of Brüninghaus.

  • Prior Art Relied Upon: Galda (a 2002 IEEE conference paper) and Brüninghaus (a 1998 IEEE conference paper).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Galda taught a method for receiving an OFDM-FDMA signal from a mobile terminal that used DFT spreading to reduce PAR. Galda’s receiver converted the signal to the frequency domain via an FFT but only generally referred to using "well known... detection techniques" for decoding. Brüninghaus was cited to supply the specific decoding method.
    • Motivation to Combine: A POSITA implementing Galda’s system would need a specific method to reverse the DFT spreading operation. Petitioner argued that Brüninghaus, which was cited as a reference in Galda, explicitly taught despreading a Fourier-spread signal by using an inverse Fast-Fourier matrix (i.e., the complex-conjugate transpose of the spreading matrix). A POSITA would therefore combine Brüninghaus's specific despreading technique with Galda’s receiver to create a complete, functional system.
    • Expectation of Success: Success would be expected because using an inverse, complex-conjugate transform to reverse a spreading operation was a known and predictable mathematical technique in signal processing.

Ground 3: Obviousness over Galda, Brüninghaus, and Dowling - Claims 10, 15-17, 19, and 24-26 are obvious over Galda in view of Brüninghaus and further in view of Dowling.

  • Prior Art Relied Upon: Galda (a 2002 IEEE conference paper), Brüninghaus (a 1998 IEEE conference paper), and Dowling (Patent 6,597,745).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground extended the combination of Galda and Brüninghaus to meet the apparatus and computer-program product claims, which require implementation via a processor and non-transitory memory. While Galda and Brüninghaus taught the functional method, they did not explicitly specify a hardware or software implementation. Dowling was introduced to provide this missing element, as it taught that OFDM receiver components and modulation techniques could be implemented as software modules executing on a programmable processor.
    • Motivation to Combine: Petitioner argued that implementing the receiver functions taught by Galda and Brüninghaus in software, as suggested by Dowling, was an obvious design choice for a POSITA. Software-based radios were well-known and offered greater flexibility and easier updates compared to fixed hardware. A POSITA would be motivated to use this known implementation approach for the combined Galda/Brüninghaus system.
    • Expectation of Success: A POSITA would have a high expectation of success in implementing the known mathematical operations from Galda and Brüninghaus in software on a standard processor, as this was a common and routine practice in the field.

4. Arguments Regarding Discretionary Denial

  • Petitioner reserved arguments regarding discretionary denial for a potential reply brief. However, it stipulated that it would not challenge the patent based on any prior art that it could have reasonably presented in the instant proceeding, in accordance with the PTAB's guidance in Sotera Wireless, Inc. v. Masimo Corporation.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 5-8, 10-12, 14-17, 19-21, and 23-26 of the ’386 patent as unpatentable.