DCT

3:23-cv-01363

GenghisComm Holdings LLC v. LG Electronics USA Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:23-cv-01363, S.D. Cal., 07/27/2023
  • Venue Allegations: Plaintiff alleges venue is proper in the Southern District of California because two LG defendants are incorporated or organized in California and maintain regular and established places of business in the district, and because LG has allegedly committed acts of infringement in the district.
  • Core Dispute: Plaintiff alleges that Defendant’s 4G LTE and 5G-capable mobile devices and related components infringe eight patents related to signal processing techniques for wireless communications.
  • Technical Context: The patents relate to methods for modulating and encoding data in wireless systems, such as Orthogonal Frequency Division Multiplexing (OFDM) and Single-Carrier Frequency-Division Multiple Access (SC-FDMA), which are foundational technologies for 4G LTE and 5G cellular standards.
  • Key Procedural History: The complaint alleges that Plaintiff sent notice letters to Defendant LG Electronics on November 2, 2020, and December 21, 2022. The first letter allegedly identified the ’842, ’227, and ’568 patents and included 105 pages of claim charts. The second letter allegedly identified the ’005, ’285, and ’792 patents. These allegations of pre-suit notice may form the basis for Plaintiff's willful infringement claims.

Case Timeline

Date Event
2001-04-26 Earliest Priority Date for ’842, ’227, ’792 Patents
2004-08-02 Earliest Priority Date for ’568, ’786, ’508, ’005, ’285 Patents
2017-09-19 U.S. Patent No. 9,768,842 Issued
2017-09-19 U.S. Patent No. 11,223,508 Issued
2019-02-05 U.S. Patent No. 10,200,227 Issued
2019-08-20 U.S. Patent No. 10,389,568 Issued
2020-11-02 Plaintiff allegedly sent notice letter to LG regarding ’842, ’227, ’568 Patents
2021-07-27 U.S. Patent No. 11,075,786 Issued
2022-02-15 U.S. Patent No. 11,252,005 Issued
2022-07-05 U.S. Patent No. 11,381,285 Issued
2022-08-23 U.S. Patent No. 11,424,792 Issued
2022-12-21 Plaintiff allegedly sent notice letter to LG regarding ’005, ’285, ’792 Patents
2023-07-27 Complaint Filed

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

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

The Invention Explained

  • Problem Addressed: The complaint alleges that certain wireless transmission schemes, such as Orthogonal Frequency Division Multiplexing (OFDM), can result in signals with a high peak-to-average power ratio (PAPR), which is inefficient for power-constrained mobile device transmitters (Compl. ¶39).
  • The Patented Solution: The invention describes a transmitter that uses a "spreader," such as a Discrete Fourier Transform (DFT), to spread data symbols across multiple subcarriers before the primary OFDM modulation step (Compl. ¶39). This "transform precoding" process generates a transmission signal that is a superposition of OFDM subcarriers but has a lower PAPR, making it more suitable for uplink communications from a mobile device (’842 Patent, Abstract; Compl. ¶39).
  • Technical Importance: This technique, known as Single-Carrier Frequency-Division Multiple Access (SC-FDMA), is a core component of the 4G LTE standard for uplink transmissions, designed to improve the power efficiency of mobile devices (Compl. ¶38).

Key Claims at a Glance

  • The complaint asserts independent claim 1 and dependent claims 2, 3, 4, 7, 8, and 9 (Compl. ¶¶33, 46, 57, 65, 74, 82, 90).
  • Independent Claim 1 requires:
    • 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"

The Invention Explained

  • Problem Addressed: The patent addresses the challenge of reducing a transmission signal's peak-to-average power in a multi-user communication system (’227 Patent, Abstract). This is a critical issue for battery-powered mobile devices using OFDM-based technologies.
  • The Patented Solution: The patent describes an apparatus with a processor and memory containing instructions to perform an "invertible transform" (such as a DFT) on data symbols, map the resulting spread symbols to OFDM subcarriers, and then perform an inverse DFT to generate a time-domain signal (’227 Patent, col. 77:22-78:20; '227 Patent, Fig. 1). This process results in a superposition of subcarriers with a reduced PAPR, consistent with SC-FDMA signal generation (Compl. ¶105).
  • Technical Importance: The technology provides a processor-based implementation for generating SC-FDMA signals, which was fundamental to enabling efficient uplink transmissions in the 4G LTE standard (Compl. ¶101).

Key Claims at a Glance

  • The complaint asserts independent claim 22 and dependent claims 24, 25, 26, and 28 (Compl. ¶¶99, 115, 123, 132, 140).
  • Independent Claim 22 requires:
    • An apparatus comprising: a processor and a non-transitory memory.
    • The memory includes 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 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 to be transmitted, 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"

  • Technology Synopsis: The patent describes an apparatus for generating an SC-FDMA signal. It involves dividing a block of symbols, transform precoding them using orthogonal spreading codes, and generating an OFDM signal with a reduced PAPR (Compl. ¶149).
  • Asserted Claims: Independent claim 24 and dependent claims 25, 26, 29, 32, 33, 34, and 44 (Compl. ¶¶148, 162, 172, 180, 189, 199, 208, 217).
  • Accused Features: The accused features are the processors and memories in LG's LTE devices that allegedly execute instructions consistent with the 4G LTE standard for uplink physical channel processing, specifically transform precoding and SC-FDMA baseband signal generation (Compl. ¶¶150, 152-154).

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

  • Technology Synopsis: The patent describes an apparatus for encoding and decoding data symbols in a wireless network using two sets of complex-valued codes. The first set of codes encodes data for transmission as a spread-OFDM signal, and the second set, which are complex conjugates of the first, is used to recover the data from a received signal (Compl. ¶225).
  • Asserted Claims: Independent claim 10 and dependent claims 11, 15, 16, 17, and 18 (Compl. ¶¶224, 240, 246, 252, 258, 264).
  • Accused Features: The accused features are the processors and memories in LG's LTE devices, which allegedly use a first set of complex-valued codes (via a DFT) for transform precoding in uplink SC-FDMA transmissions and an inverse set of codes for decoding at the receiver (eNodeB) (Compl. ¶¶228-232).

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

  • Technology Synopsis: The patent describes an apparatus for communicating in a mobile network that provisions a series of OFDM subcarriers with a plurality of different selectable subcarrier spacings. This selection of spacing provides the resulting single-carrier signal with a particular symbol period, adapting the transmission to different deployment scenarios or channel characteristics (Compl. ¶¶271, 300).
  • Asserted Claims: Independent claim 17 and dependent claims 18-22 (Compl. ¶¶270, 281, 287, 293, 299, 306).
  • Accused Features: The accused features are LG's 5G devices, which allegedly comply with the 5G wireless standard that allows for selectable subcarrier spacings (e.g., 15, 30, 60, 120, or 240 kHz) to accommodate different frequency ranges and channel conditions (Compl. ¶¶272, 275, 302).

U.S. Patent No. 11,252,005 - "Spreading and precoding in OFDM"

  • Technology Synopsis: The patent describes an apparatus for producing subcarrier values by multiplying a code matrix with a data symbol matrix. The resulting values are modulated onto a set of subcarriers to produce a time-domain waveform where the complex codes shape interference patterns to create cyclic-shifted waveforms (Compl. ¶316).
  • Asserted Claims: Independent claim 13 and dependent claims 18 and 19 (Compl. ¶¶315, 330, 339).
  • Accused Features: The accused features are LG's 5G devices, which allegedly use the 5G standard's transform precoding step (a DFT, which is a complex matrix transform) to generate subcarrier values, and then use an inverse transform (IFFT) to create a time-domain waveform from the superposition of modulated subcarriers (Compl. ¶¶320-324).

U.S. Patent No. 11,381,285 - "Transmit pre-coding"

  • Technology Synopsis: The patent describes an apparatus that uses first and second polyphase codes to encode different data symbols. These codes allegedly cause constructive and destructive interference among modulated subcarriers to produce two distinct periodic pulse waveforms centered at different times within an OFDM symbol interval (Compl. ¶348).
  • Asserted Claims: Independent claim 11 and dependent claims 17 and 19 (Compl. ¶¶347, 362, 370).
  • Accused Features: The accused features are LG's 5G devices, which allegedly use polyphasic codes in the 5G standard's transform precoding step to create pulse waveforms centered at specific times within an OFDM symbol (Compl. ¶¶353, 357).

U.S. Patent No. 11,424,792 - "Coordinated multipoint systems"

  • Technology Synopsis: The patent describes an apparatus for providing flexible channel bandwidth by selecting from different subcarrier spacings. The selected spacing provides for one of a plurality of different symbol durations, thereby adapting the signal to different usage scenarios (Compl. ¶¶379, 383).
  • Asserted Claims: Independent claim 8 and dependent claims 9 and 10 (Compl. ¶¶378, 393, 401).
  • Accused Features: The accused features are LG's 5G devices, which allegedly implement the 5G standard's support for multiple "numerologies" (subcarrier spacings) that result in different OFDM symbol durations (Compl. ¶¶383, 384).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies two categories of accused products:
    • "Accused LG LTE Devices": Mobile devices with 4G LTE connectivity, including the K22, K30, K31, K51, K8X, G8X ThinQ, Stylo 6, Xpression, Aristo 5, and Tribute Monarch smart phones, as well as C-V2X transceiver modules (Compl. ¶25).
    • "Accused LG 5G Devices": Mobile devices with 5G network connectivity, including the Wing, K92, Velvet, V50 ThinQ, and V60 ThinQ mobile phones (Compl. ¶26).

Functionality and Market Context

  • The complaint alleges that the accused devices implement and adhere to the 4G LTE and 5G wireless standards, respectively (Compl. ¶¶25, 26, 35). The core accused functionality for the LTE devices is the transmitter's use of Single-Carrier Frequency-Division Multiple Access (SC-FDMA) for uplink communications (Compl. ¶38). This process includes using a "Transform Precoding" step to spread data symbols before mapping them to physical subcarriers and generating a baseband signal (Compl. ¶¶39-41). For example, the LG Velvet is alleged to use a Qualcomm Snapdragon 765G system-on-a-chip with LTE and 5G connectivity (Compl. ¶¶37, 103). The complaint alleges LG makes, uses, sells, and imports these devices throughout the United States (Compl. ¶10).

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 spreader configured to spread a plurality of data symbols with Fourier coefficients to generate a discrete Fourier Transform (DFT)-spread data signal; The accused LTE devices' transmitters allegedly perform "Transform precoding" as defined in section 5.3.3 of the 3GPP LTE standard, using a DFT to spread data symbols across multiple subcarriers. The complaint provides an equation from the 3GPP standard illustrating this DFT operation (Compl. ¶39, Fig. at p. 10). ¶39 col. 77:22-30
a mapper configured to map the DFT-spread data signal to a plurality of OFDM subcarriers; The transmitters allegedly include a mapper that maps the spread data signals onto subcarriers consistent with section 5.4.3 of the LTE standard ("Mapping to Physical Resources"). ¶40 col. 78:6-10
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. The transmitters allegedly perform "SC-FDMA baseband signal generation" per section 5.6 of the LTE standard, which modulates the spread signals onto OFDM subcarriers to create a time-domain signal. The complaint alleges that the initial transform precoding step results in a superposition of subcarriers with a lower PAPR compared to standard OFDM (Compl. ¶41, Fig. at p. 11). ¶39, ¶41 col. 78:11-20

Identified Points of Contention

  • Scope Questions: A central question may be whether the term "OFDM spreader" as used in the patent is synonymous with the "Transform precoding" function described in the 3GPP LTE standard. The defense may argue that the claim term implies a component or function distinct from what the standard specifies.
  • Technical Questions: The complaint alleges that compliance with the LTE standard necessarily results in infringement. A key technical question will be whether the accused devices perform these steps in the precise manner required by the claim. For example, does the alleged "OFDM spreader" (the transform precoding step) itself configure the signal to have a reduced PAPR, as claimed, or is the PAPR reduction an emergent property of the entire SC-FDMA signal chain?

10,200,227 Patent Infringement Allegations

Claim Element (from Independent Claim 22) Alleged Infringing Functionality Complaint Citation Patent Citation
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 processor and memory in the accused devices allegedly execute instructions for "transform precoding" per section 5.3.3 of the LTE standard. This process uses a DFT, which is an invertible transform, to spread data symbols using complex-valued coefficients (Compl. ¶104, Fig. at p. 20). ¶104 col. 77:22-30
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; The processor and memory allegedly execute 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"). ¶106 col. 78:6-10
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. The processor and memory allegedly execute instructions for "SC-FDMA baseband signal generation" per section 5.6 of the LTE standard, which uses an M-point IDFT. The complaint alleges this process, initiated by the invertible transform, results in a signal with a reduced PAPR (Compl. ¶108, Fig. at p. 21). ¶105, ¶108 col. 78:11-20

Identified Points of Contention

  • Scope Questions: Does the claim term "invertible transform" read on the specific DFT implementation in the LTE standard's "Transform precoding" function? The defense might argue for a construction that excludes the standard's method. Further, the relationship "M>N" (asserted in dependent claim 25) is alleged to be met because the number of available subcarriers (M) exceeds the number used (N) (Compl. ¶126); this comparison may be a point of dispute.
  • Technical Questions: The infringement theory relies on the accused devices' processors (e.g., Qualcomm SM7250) executing instructions stored in memory (e.g., RAM) (Compl. ¶103). A key question will be what evidence demonstrates that these specific hardware components execute these specific steps as opposed to using dedicated, hard-wired circuitry not encompassed by the claim's "processor and memory" structure.

V. Key Claim Terms for Construction

  • The Term: "OFDM spreader" (’842 Patent, cl. 1) / "invertible transform" (’227 Patent, cl. 22)

  • Context and Importance: These terms define the core precoding/spreading step of the invention. The infringement case hinges on whether the "Transform precoding" function defined by the 3GPP LTE standard, and allegedly performed by the accused devices, falls within the scope of these terms. Practitioners may focus on these terms because the complaint's entire infringement theory is based on this equivalence.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The '227 patent claims an "invertible transform comprising complex-valued spreading codes" (col. 78:3-5), which is broad language not limited to a specific mathematical operation. The specification may describe the spreader's function in general terms of spreading data across subcarriers.
    • Evidence for a Narrower Interpretation: The abstract of the ’227 Patent explicitly identifies the invention as comprising a "Discrete Fourier Transform (DFT) spreader." The detailed description and figures may consistently use a DFT as the only disclosed embodiment, which could support an argument to limit the claim scope to DFT-based spreaders.

  • The Term: "configured to provide the superposition with a reduced peak-to-average power ratio" (’842 and ’227 Patents, cl. 1 and 22)

  • Context and Importance: This functional language requires a causal link between the "spreader" or "invertible transform" and the reduction in PAPR. The dispute will likely center on whether the claimed element itself achieves this result, or if the reduction is an attribute of the entire SC-FDMA system alleged to be infringing.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The abstract of the ’227 Patent states, "The Fourier coefficients reduce the transmission signal's peak to average power," suggesting the spreading codes themselves are the direct cause of the PAPR reduction.
    • Evidence for a Narrower Interpretation: A defendant may argue that the claim requires the "spreader" or "invertible transform" alone to be configured to achieve this result, while in the accused system, the PAPR reduction is a systemic outcome of the interplay between the DFT precoding, the mapping, and the IDFT modulation.

VI. Other Allegations

  • Indirect Infringement: The complaint includes a conclusory allegation of inducement (Compl. ¶32), but the infringement counts are for direct infringement under 35 U.S.C. § 271(a) (e.g., Compl. ¶44, ¶55). The complaint does not provide sufficient detail for analysis of specific facts supporting induced infringement, such as allegations that LG's user manuals instruct customers to perform infringing acts.
  • Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge of the patents (Compl. ¶¶409-411). The alleged basis for this knowledge is a series of notice letters sent to LG, starting on November 2, 2020, which allegedly identified specific patents-in-suit and included detailed claim charts demonstrating infringement (Compl. ¶¶27, 29).

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

  • A core issue will be one of definitional scope: will the claim terms "OFDM spreader" and "invertible transform," described in the patents, be construed to cover the specific "Transform Precoding" function defined in the 3GPP 4G LTE wireless standard? The outcome of this claim construction will be central to the infringement analysis.
  • A key evidentiary question will be one of proof of implementation: can Plaintiff provide sufficient evidence that the accused LG devices, by complying with the 4G LTE and 5G standards, necessarily practice each element of the asserted claims? The case will likely require detailed technical evidence mapping the operation of the accused processors and transmitters to the specific limitations recited in the patent claims.
  • A central legal question will be willfulness: given the allegation that Plaintiff provided LG with notice letters including detailed infringement charts more than two years before filing suit, the court will likely examine whether LG's continued sales of the accused products constituted objective recklessness, which could expose LG to the risk of enhanced damages.