DCT

2:25-cv-00837

Empire Technology Development LLC v. Lenovo Group Ltd

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Key Events
Amended Complaint
amended complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00837, E.D. Tex., 01/21/2026
  • Venue Allegations: Plaintiff alleges venue is proper because Defendants transact business in the district, have committed acts of infringement in the district, and maintain a regular and established place of business through authorized sellers and service providers. Alternatively, as foreign corporations not residing in the United States, venue is alleged to be proper in any judicial district.
  • Core Dispute: Plaintiff alleges that Defendant’s 5G-compatible smartphones, tablets, and computers infringe patents related to adaptive power control and channel estimation techniques for wireless communications.
  • Technical Context: The technologies at issue concern methods for improving the efficiency, performance, and regulatory compliance of wireless devices operating in modern cellular networks such as 5G.
  • Key Procedural History: The complaint alleges the patents-in-suit originated from research at the University of Texas and were exclusively licensed to Plaintiff’s predecessor-in-interest in 2009. Plaintiff asserts that it provided Defendant with notice of the patents in a portfolio offered for sale beginning in May 2019. The complaint also notes a pending Inter Partes Review (IPR) proceeding concerning the ’120 Patent, IPR2024-00896.

Case Timeline

Date Event
2009-03-18 U.S. Patent No. 8,798,120 Priority Date
2009-06-26 Master License Agreement for patents-in-suit effective
2010-08-20 U.S. Patent No. 8,565,331 Priority Date
2013-10-22 U.S. Patent No. 8,565,331 Issued
2014-08-05 U.S. Patent No. 8,798,120 Issued
2019-05-31 Plaintiff’s counsel allegedly first contacted Defendant regarding a patent portfolio including the patents-in-suit
2020-01-06 Defendant allegedly released first accused product (Flex 5G laptop) in the U.S.
2026-01-21 Complaint Filing Date

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

U.S. Patent No. 8,798,120 - "METHODS AND COMMUNICATION SYSTEMS HAVING ADAPTIVE MODE SELECTION"

  • Patent Identification: U.S. Patent No. 8,798,120, “METHODS AND COMMUNICATION SYSTEMS HAVING ADAPTIVE MODE SELECTION,” issued August 5, 2014 (Compl. ¶31).

The Invention Explained

  • Problem Addressed: The complaint asserts that modern wireless devices must balance competing demands: prolonging battery life, delivering high performance (which may require short bursts of high power), and complying with strict FCC regulations on radio frequency (RF) exposure (Compl. ¶¶37-39). The patent addresses the selection of transmission modes in Multiple-Input Multiple-Output (MIMO) and Single-Input Multiple-Output (SIMO) communication systems (’120 Patent, col. 1:15-24).
  • The Patented Solution: The invention is a mobile station and method for adaptively selecting between a multi-antenna (MIMO) transmission mode and a single-antenna (SIMO) transmission mode (’120 Patent, Abstract). This selection is based on a control signal that is generated, at least in part, by considering the power consumption of the transmission circuitry and the device's power consumption during idle periods (’120 Patent, col. 10:17-20). By dynamically choosing the most appropriate mode, the system can optimize for factors like energy efficiency.
  • Technical Importance: This adaptive mode selection allows a device to intelligently manage its power resources to balance data throughput, energy consumption, and regulatory compliance in real-time wireless network conditions (Compl. ¶¶36, 39).

Key Claims at a Glance

  • The complaint asserts independent claim 25 (Compl. ¶57).
  • The essential elements of claim 25 are:
    • A mobile station comprising a first antenna and a second antenna.
    • First and second circuitry coupled to the respective antennas for processing transmission signals.
    • A controller configured to receive a control signal and, based on it, select between a MIMO mode (both antennas transmit) and a SIMO mode (only one antenna transmits).
    • The control signal is based, at least in part, on the power consumption of the first and second circuitry.
    • The control signal is based, at least in part, on an idle power consumption of the mobile station.
  • The complaint reserves the right to assert other claims of the ’120 Patent (Compl. ¶63).

U.S. Patent No. 8,565,331 - "INSERTING AND DECODING REPLICATED DATA SYMBOLS IN WIRELESS COMMUNICATIONS"

  • Patent Identification: U.S. Patent No. 8,565,331, “INSERTING AND DECODING REPLICATED DATA SYMBOLS IN WIRELESS COMMUNICATIONS,” issued October 22, 2013 (Compl. ¶33).

The Invention Explained

  • Problem Addressed: To ensure reliable communication, a wireless receiver must accurately estimate the characteristics of the communication channel, a process known as channel estimation (’331 Patent, col. 1:26-34). This is often accomplished by transmitting known "pilot symbols," which the receiver uses as a reference. However, transmitting these non-data symbols reduces the overall data rate available to the user (’331 Patent, col. 2:1-6).
  • The Patented Solution: The patent proposes a method where, in addition to using traditional pilot symbols for an initial channel estimate, a transmitter replicates actual data symbols from one data stream and inserts them into a second data stream (’331 Patent, Abstract; col. 4:7-14). The receiver can decode this replicated data using the initial estimate and then, because the data is now known, use it as a new reference point to generate an "updated estimate of the channel matrix." This refined estimate is then used to decode subsequent data more accurately, improving reliability without dedicating as much transmission overhead to non-data pilot symbols (’331 Patent, col. 4:7-14).
  • Technical Importance: This technique aims to improve the accuracy of channel estimation in multi-antenna systems, which is critical for achieving reliable, high-speed data transmission in complex wireless environments (Compl. ¶42).

Key Claims at a Glance

  • The complaint asserts independent claim 1 (Compl. ¶100).
  • The essential elements of claim 1, a method of decoding, are:
    • Receiving a pilot symbol.
    • Estimating a channel matrix based on the pilot symbol.
    • Receiving replicated data from multiple data streams.
    • Decoding the replicated data using the estimated channel matrix.
    • Generating an updated estimate of the channel matrix based on the decoded replicated data.
    • Decoding subsequently received signals using the updated estimate.
  • The complaint reserves the right to assert other claims of the ’331 Patent (Compl. ¶105).

III. The Accused Instrumentality

Product Identification

  • The complaint accuses a wide range of Lenovo’s 5G-compatible products, including the Flex 5G laptop; Edge, Moto, One, and Razr series smartphones; and Tab series tablets (Compl. ¶¶54-56).

Functionality and Market Context

  • The accused functionality for the ’120 Patent infringement is Defendant’s "Smart Transmit" technology (versions 1.0, 2.0, and 3.0), which is present in its 5G-compatible devices (Compl. ¶57). This technology is alleged to manage RF transmission power to optimize performance while complying with regulatory limits, purportedly by controlling instantaneous and time-averaged power output (Compl. ¶¶78-82).
  • For the ’331 Patent, the accused functionality resides in devices containing 5G-compatible modems, such as the Qualcomm Snapdragon X55 (Compl. ¶107). These modems perform channel estimation using pilot signals and employ techniques like "spatial diversity," which involves sending the same data across different paths for reliability (Compl. ¶¶110, 120). The complaint alleges these devices are significant products in the 5G device market (Compl. ¶43).

IV. Analysis of Infringement Allegations

U.S. Patent No. 8,798,120 Infringement Allegations

Claim Element (from Independent Claim 25) Alleged Infringing Functionality Complaint Citation Patent Citation
[a] a first antenna and a second antenna; The accused Flex 5G product contains multiple antennas, identified in FCC submissions as "Wireless WAN antennas." The complaint includes a diagram from an FCC submission showing the location of "WWAN ANT 1" and "WWAN ANT 3" (Compl. p. 26). ¶¶66-67 col. 10:3-4
[b] first circuitry coupled to the first antenna...; second circuitry coupled to the second antenna...; The accused products contain modules and circuitry for processing signals, such as the RF front-end (RFFE) solutions designed to work with the Snapdragon X55 5G modem. An internal photograph of the Flex 5G shows these antenna modules and associated circuitry (Compl. p. 28). ¶¶72-74 col. 10:5-10
[c] a controller...to select between a multiple-input multiple-output (MIMO) mode...and a single-input multiple-output (SIMO) mode... The accused products are compatible with LTE Release 12, which defines distinct uplink transmission modes for SIMO and MIMO that can be selected via a Downlink Control Information (DCI) signal. ¶¶75-77 col. 10:11-17
[d] wherein the control signal is based, at least in part, on a power consumption of the first and second circuitry, The accused "Smart Transmit" technology allegedly manages and optimizes transmit power. A screenshot from a promotional video shows transmit power being dynamically adjusted over time, which the complaint alleges is based on the power consumption of the RF circuitry (Compl. p. 32). ¶¶78-80 col. 10:17-19
[e] wherein the control signal is based, at least in part, on an idle power consumption of the mobile station. The complaint alleges that because "Smart Transmit" relies on time-averaging transmit power, it necessarily accounts for periods of idle time in its overall power budget. An RF Exposure Report test plot is cited to show power management behavior that allegedly implicates idle states (Compl. p. 35). ¶¶86-89 col. 10:19-20
  • Identified Points of Contention:
    • Scope Questions: A central question may be whether the selection of standardized LTE "Transmission Modes" constitutes the specific "select[ion] between a...MIMO mode...and a...SIMO mode" as claimed by the patent.
    • Technical Questions: The complaint's assertion for the "idle power consumption" element appears to be based on an inference that time-averaging power management inherently "accounts for" idle periods. A key point of contention may be whether this inferential link is sufficient to prove the control signal is affirmatively "based...on" idle power consumption, or if the claim requires a more direct measurement or input related to the device's idle state.

U.S. Patent No. 8,565,331 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
[a] receiving a pilot symbol over the communications channel; The accused products' Snapdragon X55 modem receives pilot signals (also called reference signals), which are a fundamental component of 4G and 5G cellular systems for channel estimation. ¶¶109-111 col. 2:1-3
[b] estimating a channel matrix of the communications channel based, at least in part, on the pilot symbol; The accused products perform channel estimation based on received pilot symbols, such as Demodulation Reference Signals (DM-RS). The complaint provides a diagram illustrating how DM-RS are used to estimate the channel (Compl. p. 41). ¶¶112-115 col. 2:61-65
[c] receiving replicated data from multiple data streams transmitted over the communications channel; The complaint alleges that the Snapdragon X55 modem's use of "spatial diversity"—a technique where "the same data" is sent "across different...spatial, paths"—satisfies this limitation. ¶¶117-120 col. 2:65-66
[d] decoding the replicated data using the estimated channel matrix; Decoding any received data, including the data sent via spatial diversity, requires using the channel estimate. ¶¶121-124 col. 2:67-68
[e] generating an updated estimate of the channel matrix based, at least in part, on the replicated data; and The complaint alleges that data within a received data block is "also used to improve or update the channel estimate," thereby generating an updated estimate based on what it defines as replicated data. ¶¶127-129 col. 3:1-3
[f] decoding subsequently received signals over the communications channel using the updated estimate of the channel matrix. This updated channel estimate is then allegedly used for decoding subsequent transmissions to improve accuracy. ¶¶130-132 col. 16:6-9
  • Identified Points of Contention:
    • Scope Questions: The case may turn on the definition of "replicated data." A question for the court will be whether the accused implementation of "spatial diversity," a known technique for improving transmission reliability, falls within the patent's description of replicating data symbols from one stream into another for the specific purpose of updating a channel estimate.
    • Technical Questions: What evidence does the complaint provide that the data received via spatial diversity is specifically used to "generat[e] an updated estimate of the channel matrix"? The complaint alleges this occurs, but the provided support speaks generally to channel estimation rather than detailing this specific feedback loop in the accused products.

V. Key Claim Terms for Construction

  • The Term: "based, at least in part, on an idle power consumption of the mobile station" (’120 Patent, Claim 25)
  • Context and Importance: This term is critical because it links the mode selection logic to a specific condition: the power consumed when the device is not actively transmitting. The infringement argument hinges on whether the accused "Smart Transmit" feature, which uses time-averaging, meets this requirement. Practitioners may focus on this term because it appears to be the most technically specific and potentially difficult limitation for the plaintiff to prove directly.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The specification discusses energy efficiency and mentions that the "idle time is a time during which the transceiver may be waiting to send data" (’120 Patent, col. 7:59-62). This could support an argument that any power management system that accounts for both active and inactive periods in its energy budget is "based on" idle power consumption.
    • Evidence for a Narrower Interpretation: The claim language requires the "control signal" itself to be "based...on" this factor. This suggests a more direct causal link, potentially requiring a measurement or consideration of idle power as an input to the selection algorithm. The patent's detailed embodiments do not explicitly describe measuring idle power and feeding it into the mode selector, which may support a narrower construction.
  • The Term: "replicated data" (’331 Patent, Claim 1)
  • Context and Importance: Plaintiff's infringement theory equates this term with data transmitted using "spatial diversity." The viability of the infringement claim for the ’331 patent depends on this interpretation. A dispute over whether these two concepts are technically and legally synonymous is foreseeable.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The patent abstract describes the invention as "inserting at least a portion of data from a first data stream into a second data stream." An argument could be made that sending identical data streams over different antennas or paths is a form of this process.
    • Evidence for a Narrower Interpretation: The patent's detailed description and figures illustrate a specific action: copying a symbol from one distinct stream and placing it into another distinct stream at a specific location to serve as a new reference point (e.g., ’331 Patent, Fig. 3, showing symbol 312 replicated). This appears technically distinct from spatial diversity, which typically involves transmitting entire identical streams for redundancy and reliability, not for creating new channel estimation pilots from data.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement for both patents. Inducement is based on allegations that Defendants provide the accused products along with instructions, manuals, and software that encourage and enable end-users to operate them in an infringing manner (Compl. ¶¶60, 102).
  • Willful Infringement: Willfulness is alleged for both patents based on pre-suit knowledge. The complaint asserts that Plaintiff's counsel contacted Defendant by email starting on May 31, 2019, identifying a portfolio of patents for sale that included the ’120 and ’331 Patents. This alleged notice predates the January 6, 2020 launch of the first accused product (Compl. ¶¶54, 91, 134).

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

  • A core issue will be one of definitional scope: Can the term "replicated data," as taught in the ’331 Patent for creating new channel estimation reference points, be construed to cover the accused products’ use of "spatial diversity," a conventional technique for improving transmission reliability?
  • A key evidentiary question will be one of causality and proof: For the ’120 Patent, does the accused "Smart Transmit" system's use of time-averaged power control provide a sufficient evidentiary basis to meet the claim requirement that mode selection be "based, at least in part, on an idle power consumption of the mobile station," or is this connection too indirect to prove infringement?
  • A third central question will concern willfulness: Did the 2019 communications, which framed the patents as part of a portfolio for sale, provide Defendant with knowledge of infringement that was sufficiently clear and explicit to support a finding of willful infringement for products launched thereafter?