DCT

2:22-cv-00066

GenghisComm Holdings LLC v. ASUSTeK Computer Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:22-cv-00066, E.D. Tex., 03/07/2022
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant is not a resident of the United States and may be sued in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s 4G LTE and 5G-capable mobile devices, including smartphones and tablets, infringe five patents related to signal processing techniques for wireless communications.
  • Technical Context: The technology at issue involves methods for generating and processing signals in Orthogonal Frequency Division Multiplexing (OFDM) and Single-Carrier Frequency Division Multiple Access (SC-FDMA) systems, which are foundational to modern 4G LTE and 5G cellular standards.
  • Key Procedural History: The complaint alleges that Plaintiff provided Defendant with pre-suit notice of U.S. Patent Nos. 9,768,842, 10,200,227, and 10,389,568 via a letter with claim charts sent on November 19, 2020. Plaintiff alleges that despite subsequent communications, Defendant did not enter into a license agreement. The complaint itself is alleged to serve as notice for U.S. Patent Nos. 11,075,786 and 11,223,508.

Case Timeline

Date Event
2002-05-14 Earliest Patent Priority Date ('842, '227, '568, '786, '508 Patents)
2017-09-19 U.S. Patent No. 9,768,842 Issues
2019-02-05 U.S. Patent No. 10,200,227 Issues
2019-08-20 U.S. Patent No. 10,389,568 Issues
2020-11-19 Pre-suit notice letter sent to Defendant
2021-07-27 U.S. Patent No. 11,075,786 Issues
2022-01-11 U.S. Patent No. 11,223,508 Issues
2022-03-07 Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,768,842 - "Pre-coding in multi-user MIMO"

  • Patent Identification: U.S. Patent No. 9,768,842, titled "Pre-coding in multi-user MIMO," issued September 19, 2017.

The Invention Explained

  • Problem Addressed: The patent family addresses technical challenges in wireless communication, including the high peak-to-average power ratio (PAPR) of signals in Orthogonal Frequency Division Multiplexing (OFDM) systems, which can require expensive and power-inefficient amplifiers in mobile devices ('227 Patent, col. 7:59-67).
  • The Patented Solution: The invention describes a transmitter that uses a "Discrete Fourier Transform (DFT) spreader" to pre-code data symbols with Fourier coefficients before they are modulated onto OFDM subcarriers by an inverse-DFT ('842 Patent, Abstract). This two-step transform process (DFT followed by an inverse-DFT) generates what is technically known as a Single-Carrier Frequency Division Multiple Access (SC-FDMA) signal, which is designed to have a lower PAPR than a conventional OFDM signal ('842 Patent, Abstract). The overall architecture is depicted in Figure 30A of the patent, showing the signal flow from a DFT Spreader to a Mapper and then to an IFFT ('842 Patent, Fig. 30A).
  • Technical Importance: This technique was adopted as the uplink transmission scheme for 4G LTE cellular standards, as its lower PAPR allows mobile devices to use more power-efficient and less costly power amplifiers, extending battery life.

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 2, 3, 4, 7, 8, and 9 (Compl. ¶¶29, 42, 53, 61, 70, 78, 86).
  • Independent Claim 1 recites:
    • An OFDM transmitter, comprising:
    • an OFDM spreader configured to spread a plurality of data symbols with Fourier coefficients to generate a discrete Fourier Transform (DFT)-spread data signal;
    • a mapper configured to map the DFT-spread data signal to a plurality of OFDM subcarriers; and
    • an OFDM modulator configured to modulate the DFT-spread data signal onto the plurality of OFDM subcarriers to produce an OFDM transmission signal comprising a superposition of the OFDM subcarriers, wherein the OFDM spreader is configured to provide the superposition with a reduced peak-to-average power ratio.

U.S. Patent No. 10,200,227 - "Pre-coding in multi-user MIMO"

  • Patent Identification: U.S. Patent No. 10,200,227, titled "Pre-coding in multi-user MIMO," issued February 5, 2019.

The Invention Explained

  • Problem Addressed: The patent background describes inter-cell interference as a "primary bottleneck for spectral efficiency" in traditional cellular networks and notes the high cost and inefficiency of base station hardware ('227 Patent, col. 1:17-19, col. 2:30-46).
  • The Patented Solution: The patent describes an apparatus with a processor and memory containing instructions to perform a signal generation process. This process involves an "invertible transform" (such as a DFT) to spread data symbols, mapping the spread symbols to OFDM subcarriers, and then using an "M-point inverse discrete Fourier transform (IDFT)" to generate a time-domain signal ('227 Patent, Claim 22). This method is designed to create a final transmission signal with a "reduced peak-to-average power ratio," which is a key characteristic of SC-FDMA signals ('227 Patent, col. 7:59-67).
  • Technical Importance: The technology provides a processor-based implementation of the SC-FDMA signal generation process, which is fundamental for user equipment (e.g., smartphones) to communicate efficiently on the 4G LTE uplink.

Key Claims at a Glance

  • The complaint asserts independent claim 22 and dependent claims 24, 25, 26, and 28 (Compl. ¶¶95, 111, 119, 128, 136).
  • Independent Claim 22 recites:
    • An apparatus comprising a processor and a non-transitory memory with instructions executable by the processor to:
    • perform an invertible transform on a set of data symbols to generate a plurality N of spread data symbols, the invertible transform comprising complex-valued spreading codes;
    • map the N spread data symbols to at least N subcarriers of a plurality M of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers to generate a set of complex subcarrier amplitudes; and
    • perform an M-point inverse discrete Fourier transform (IDFT) on the set of complex subcarrier amplitudes to generate a time-domain sequence...wherein the invertible transform is configured to provide the superposition with a reduced peak-to-average power ratio.

U.S. Patent No. 10,389,568 - "Single carrier frequency division multiple access baseband signal generation"

  • Patent Identification: U.S. Patent No. 10,389,568, "Single carrier frequency division multiple access baseband signal generation," issued August 20, 2019.
  • Technology Synopsis: This patent describes an apparatus for generating an SC-FDMA signal, which is a key component of the 4G LTE uplink. The invention involves dividing a block of symbols, applying transform precoding using orthogonal spreading codes (such as from a DFT) to reduce PAPR, and then generating an OFDM signal modulated by these precoded symbols (Compl. ¶¶145, 150-153).
  • Asserted Claims: Independent claims 24 and 44 (Compl. ¶¶145, 213).
  • Accused Features: The processors and memory within the Accused Asus LTE Devices are alleged to execute instructions for LTE physical channel uplink processing consistent with the claimed method, including transform precoding and SC-FDMA signal generation (Compl. ¶¶148, 150-152).

U.S. Patent No. 11,075,786 - "Multicarrier sub-layer for direct sequence channel and multiple-access coding"

  • Patent Identification: U.S. Patent No. 11,075,786, "Multicarrier sub-layer for direct sequence channel and multiple-access coding," issued July 27, 2021.
  • Technology Synopsis: The patent describes a communication apparatus that employs a first set of complex-valued codes to encode data and a second set (which are complex conjugates of the first) to recover the data. The encoded data is then applied to selected subcarriers to create a spread-OFDM signal. This mirrors the SC-FDMA process where a device uses a DFT for encoding and the base station uses an inverse DFT for decoding (Compl. ¶¶221, 224, 228).
  • Asserted Claims: Independent claim 10 (Compl. ¶221).
  • Accused Features: The Accused Asus LTE Devices allegedly use a DFT (a first set of codes) for transform precoding in the uplink, while the receiving base station uses an inverse DFT (the second, conjugate set of codes) for decoding, which is alleged to map directly onto the claimed invention (Compl. ¶¶224, 228).

U.S. Patent No. 11,223,508 - "Wireless communications using flexible channel bandwidth"

  • Patent Identification: U.S. Patent No. 11,223,508, "Wireless communications using flexible channel bandwidth," issued January 11, 2022.
  • Technology Synopsis: This patent addresses flexible "numerologies" used in 5G wireless standards. It claims an apparatus that provisions selectable subcarrier spacings for OFDM communications, performs DFT coding on data, and then generates a single-carrier signal using an inverse-DFT. Selecting different subcarrier spacings results in different symbol periods, providing the flexibility required for diverse 5G deployment scenarios (Compl. ¶¶267, 271-272, 298).
  • Asserted Claims: Independent claim 17 (Compl. ¶267).
  • Accused Features: The Accused Asus 5G Devices are alleged to practice the 5G standard, which requires selectable subcarrier spacings (e.g., 15, 30, 60, 120, 240 kHz) and the use of transform precoding to generate SC-FDMA signals for uplink, thereby infringing the claims (Compl. ¶¶270-271).

III. The Accused Instrumentality

  • Product Identification: The complaint identifies two categories of accused products: "Accused Asus LTE Devices" and "Accused Asus 5G Devices" (Compl. ¶¶18-19). The LTE devices include specific ZenFone and ZenPad models, while the 5G devices include the ZenFone 7 and 8 series mobile phones (Compl. ¶¶18-19).
  • Functionality and Market Context: The accused instrumentalities are smartphones and tablets equipped with hardware, such as the Qualcomm Snapdragon 888 5G Mobile Platform, and software for connecting to 4G LTE and 5G cellular networks (Compl. ¶¶33, 99). The core accused functionality is their implementation of the uplink transmission schemes defined by the 3GPP LTE and 5G standards, specifically SC-FDMA (Compl. ¶34). This involves using a DFT for "transform precoding" to spread data symbols before modulating them onto OFDM subcarriers with an inverse-DFT for transmission to the network (Compl. ¶¶35, 37). The complaint alleges these products are sold and advertised in the United States through Defendant's website and other retailers (Compl. ¶8).

IV. Analysis of Infringement Allegations

9,768,842 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
An OFDM transmitter, comprising: The Accused Asus LTE Devices contain a transmitter for LTE network connectivity, such as within the Qualcomm Snapdragon 888 5G Mobile Platform. ¶33 Abstract
an OFDM spreader configured to spread a plurality of data symbols with Fourier coefficients to generate a discrete Fourier Transform (DFT)-spread data signal; The transmitter performs "Transform precoding" as required by the LTE standard, which uses a discrete Fourier transform to spread data symbols across multiple subcarriers. The complaint provides an equation from the 3GPP LTE standard detailing this step (Compl. ¶35, p. 7). ¶35 Abstract; Fig. 30A
a mapper configured to map the DFT-spread data signal to a plurality of OFDM subcarriers; The transmitter maps the spread data signals to physical resource elements (subcarriers) as required by section 5.4.3 of the LTE standard ("Mapping to Physical Resources"). ¶36 Abstract; Fig. 30A
an OFDM modulator configured to modulate the DFT-spread data signal onto the plurality of OFDM subcarriers...wherein the OFDM spreader is configured to provide the superposition with a reduced peak-to-average power ratio. The transmitter performs SC-FDMA baseband signal generation per section 5.6 of the LTE standard, which modulates the mapped signals onto subcarriers. This process, initiated by transform precoding, allegedly results in a signal with a lower peak-to-average power ratio (PAPR). ¶¶35, 37 Abstract; Fig. 30A

10,200,227 Patent Infringement Allegations

Claim Element (from Independent Claim 22) Alleged Infringing Functionality Complaint Citation Patent Citation
An apparatus comprising: a processor; and a non-transitory memory...including a set of instructions...executable by the processor to: The Accused Asus LTE Devices contain processors (e.g., Qualcomm Snapdragon 888) and non-transitory memory (e.g., LPRDDR) that store and execute instructions for LTE physical channel processing. ¶99 col. 14:55-62
perform an invertible transform on a set of data symbols to generate a plurality N of spread data symbols, the invertible transform comprising complex-valued spreading codes; The memory includes instructions to perform "transform precoding" on data symbols using a discrete Fourier transform (DFT), which is an invertible transform, as defined in section 5.3.3 of the LTE standard. ¶100 col. 7:59-67; Fig. 31
map the N spread data symbols to at least N subcarriers of a plurality M of Orthogonal Frequency Division Multiplexing (OFDM) subcarriers to generate a set of complex subcarrier amplitudes; and The memory includes instructions for mapping the N spread data symbols to N subcarriers, consistent with section 5.4.3 of the LTE standard ("Mapping to physical resources"). ¶102 col. 7:1-6; Fig. 31
perform an M-point inverse discrete Fourier transform (IDFT)...wherein the invertible transform is configured to provide the superposition with a reduced peak-to-average power ratio. The memory includes instructions to perform SC-FDMA baseband signal generation using an M-point IDFT, per section 5.6 of the LTE standard. The complaint includes an equation for this step (Compl. ¶105, p. 22). This process is alleged to result in a signal with a reduced PAPR. ¶¶101, 104, 105 col. 7:7-12; col. 7:65
  • Identified Points of Contention:
    • Scope Questions: The infringement theory for all asserted patents rests on the allegation that implementing mandatory portions of the 4G LTE and 5G standards necessarily infringes the claims. A central point of contention may be whether the general terms used in the claims (e.g., "OFDM spreader," "invertible transform") should be construed to broadly cover the specific "Transform precoding" function in the 3GPP standards, or if they should be limited to the "Carrier Interferometry" embodiments detailed in the patents' specifications.
    • Technical Questions: The claims require that the apparatus be "configured to provide" a reduced PAPR. The complaint alleges this is an inherent feature of the transform precoding process used in SC-FDMA (Compl. ¶¶35, 101). A question for the court may be whether this inherent property of a standardized method satisfies the "configured to" limitation, or if Plaintiff must show a specific design choice made by the Defendant to achieve that result beyond mere standards compliance.

V. Key Claim Terms for Construction

  • Term: "OFDM spreader" ('842 Patent, Claim 1)

    • Context and Importance: This term is the central active element in claim 1 of the '842 Patent. Its construction will determine whether the "Transform precoding" block mandated by the LTE standard for uplink SC-FDMA signal generation falls within the scope of the claim. Practitioners may focus on this term to dispute whether practicing the standard constitutes infringement.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The patent abstract describes the element simply as a "DFT spreader" that uses "Fourier coefficients" ('842 Patent, Abstract). This general language may support a construction that covers any DFT-based precoding block.
      • Evidence for a Narrower Interpretation: The patent’s Figure 30A includes the parenthetical "(CI Coder)" below the "DFT Spreader" block ('842 Patent, Fig. 30A). A defendant may argue this links the term to the specific "Carrier Interferometry" (CI) techniques described throughout the patent family, potentially narrowing the claim scope to exclude a standard SC-FDMA implementation if it can be distinguished from "CI."

  • Term: "invertible transform" ('227 Patent, Claim 22)

    • Context and Importance: The definition of this term is critical for determining whether the DFT operation used in the LTE standard's "Transform precoding" step meets this claim limitation. The dispute will likely center on whether a standard DFT operation is legally equivalent to the "invertible transform" as contemplated by the patent.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification explicitly describes a "Discreet Fourier Transform (DFT)-spread OFDM signal" and notes that a DFT is an invertible transform, supporting a broad definition that includes the accused functionality ('227 Patent, col. 8:60-62).
      • Evidence for a Narrower Interpretation: The specification also describes the invention in the context of "cooperative subspace processing" and "Carrier Interferometry codes" ('227 Patent, col. 8:5-7, col. 7:59-62). A defendant may argue that the "invertible transform" should be construed in this narrower context, requiring more than the simple application of a standard DFT as used for SC-FDMA.

VI. Other Allegations

  • Indirect Infringement: The complaint states that Asus "has continued to infringe, and/or induce the infringement of, the Patents-in-Suit" (Compl. ¶28), but it does not plead separate counts for indirect infringement. The factual basis for an inducement allegation would likely be Defendant’s alleged knowledge of the patents (from the 2020 notice letter) and subsequent sales of standard-compliant products to customers with the intent that they use them in an infringing manner.
  • Willful Infringement: The complaint includes a specific allegation of willful infringement (Compl. ¶¶311-313). The basis for willfulness regarding the '842, '227, and '568 patents is alleged pre-suit knowledge stemming from a November 19, 2020 notice letter that included claim charts (Compl. ¶¶20, 311). For the '786 and '508 patents, any willfulness would be based on post-suit knowledge, as the complaint itself is alleged to be the first notice (Compl. ¶27).

VII. Analyst’s Conclusion: Key Questions for the Case

  • A core issue will be one of claim scope versus industry standard: Can the patentee's general claim terms (e.g., "OFDM spreader," "invertible transform") be construed to cover mandatory signal processing functions ("Transform precoding") in the 4G LTE and 5G standards, or will the terms be limited to the specific "Carrier Interferometry" embodiments described in the specification, potentially allowing the defendant to argue it is merely practicing a public standard?
  • A central legal question will be one of functionality versus configuration: Does an accused device that implements a standardized process (SC-FDMA), which is widely known to have an inherent technical property (reduced PAPR), satisfy a claim limitation requiring that the device be "configured to provide" that property, or must the plaintiff prove a more specific design choice by the defendant to achieve that result?