DCT
4:22-cv-03744
Swirlate IP LLC v. Noodoe Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Swirlate IP LLC (Texas)
- Defendant: Noodoe Inc. (Delaware, with a place of business in Texas)
- Plaintiff’s Counsel: Ni, Wang & Massand, PLLC
- Case Identification: 4:22-cv-03744, S.D. Tex., 10/28/2022
- Venue Allegations: Venue is alleged to be proper in the Southern District of Texas because the Defendant maintains a regular and established place of business in Houston, Texas, and has allegedly committed acts of infringement within the district.
- Core Dispute: Plaintiff alleges that Defendant’s Noodoe EV G100 4G Gateway infringes two patents related to methods for improving data transmission reliability in wireless systems by using different signal constellation mappings for initial transmissions and subsequent retransmissions.
- Technical Context: The technology addresses the challenge of maintaining data integrity in wireless communication protocols like Hybrid Automatic Repeat Request (HARQ) by optimizing how data bits are mapped to modulation symbols to improve performance over unreliable channels.
- Key Procedural History: The '622 Patent is a continuation of the application that resulted in the '961 Patent, and both patents share an identical specification. The complaint notes that during the prosecution of the '622 Patent, the applicant distinguished the invention from prior art by emphasizing that it employs different bit mappings for the initial transmission and the retransmission to average out communication reliabilities and improve the likelihood of correctly receiving the data.
Case Timeline
| Date | Event |
|---|---|
| 2002-10-18 | Earliest Priority Date ('961 & '622 Patents) |
| 2006-12-26 | U.S. Patent No. 7,154,961 Issued |
| 2009-07-28 | U.S. Patent No. 7,567,622 Issued |
| 2022-10-28 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,154,961 - "Constellation Rearrangement for ARQ Transmit Diversity Schemes," issued December 26, 2006
The Invention Explained
- Problem Addressed: In wireless systems using Automatic Repeat reQuest (ARQ) protocols, higher-order modulation formats (like 16-QAM or 64-QAM) are used to increase data rates. However, a side effect is that the individual bits mapped to a single modulation symbol have different levels of reliability against transmission errors. Conventional systems did not account for this variation, which could lead to degraded decoder performance ('961 Patent, col. 2:1-11; Compl. ¶14).
- The Patented Solution: The invention proposes improving performance by applying different signal constellation mappings for different transmissions of the same data, for instance, between an initial transmission and a subsequent retransmission over a different diversity branch. By altering the bit-to-symbol mapping, the reliability levels of the individual bits are effectively averaged out when the signals are combined at the receiver, increasing the probability of a correct decoding ('961 Patent, col. 2:18-29; Compl. ¶15).
- Technical Importance: This technique provided a method to enhance the robustness of HARQ, a fundamental technology for reliable data transfer in modern mobile communication standards, without requiring additional bandwidth. ('961 Patent, col. 1:12-15).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶16).
- Claim 1 recites a method for ARQ re-transmission with the following key steps:
- Modulating data packets using a first modulation scheme to obtain first data symbols.
- Transmitting the first data symbols over a first diversity branch.
- Modulating the same data packets using a second modulation scheme to obtain second data symbols.
- Transmitting the second data symbols over a second diversity branch.
- Demodulating the received symbols using the respective modulation schemes.
- Diversity combining the demodulated data, where the modulation schemes are specified as being 16-QAM and a number of log2(M) schemes are used.
- The complaint does not explicitly reserve the right to assert dependent claims.
U.S. Patent No. 7,567,622 - "Constellation Rearrangement for ARQ Transmit Diversity Schemes," issued July 28, 2009
The Invention Explained
- Problem Addressed: As this patent shares its specification with the ’961 Patent, it addresses the same problem of unequal bit reliabilities in higher-order modulation schemes ('622 Patent, col. 2:1-11; Compl. ¶28).
- The Patented Solution: The solution is fundamentally the same: using different modulation mappings for retransmissions. However, the claims of the '622 Patent add specific operational conditions. The complaint highlights that an advantage of the claimed subject matter is reducing overall data traffic by performing retransmission only when an initial transmission fails, as opposed to prior art that might always transmit data over multiple parallel paths (Compl. ¶30).
- Technical Importance: This claimed method focuses on implementing the constellation rearrangement technique in a more resource-efficient manner, which is crucial for managing load and latency in commercial wireless networks (Compl. ¶30).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (Compl. ¶31).
- Claim 1 recites a method for ARQ re-transmission with the following key steps:
- Modulating data packets using a first mapping of a higher-order modulation scheme.
- Transmitting the first data symbols over a first diversity branch.
- Receiving at the transmitter a repeat request if the first transmission was not successfully decoded.
- In response to the repeat request, modulating the data packets using a second mapping of the higher-order modulation scheme.
- In response to the repeat request, transmitting the resulting second data symbols over a second diversity branch.
- The claim further requires that the first and second mappings are pre-stored in a memory table.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
Product Identification
- The Noodoe EV G100, described as a "4G Gateway" for electric vehicle charging stations (Compl. ¶16). An image of the product is provided in the complaint. (Compl. p. 37).
Functionality and Market Context
- The complaint alleges the Noodoe EV G100 functions as a wireless communication device operating on an LTE network (Compl. ¶17). Its accused functionality centers on its use of a Hybrid Automatic Repeat Request (HARQ) protocol to transmit data. The complaint alleges the device uses modulation schemes including QPSK, 16QAM, and 64QAM (Compl. ¶18, ¶32). The infringement allegations are based on how the device allegedly modulates and re-transmits data packets when errors occur, specifically by using an "Adaptive Re-transmission" feature where the Modulation Coding Scheme (MCS) is changed for the re-sent data (Compl. ¶20, ¶36). A diagram from a third-party technical source is used to illustrate the HARQ process allegedly practiced by the device. (Compl. p. 39).
- The complaint does not provide sufficient detail for analysis of the product's commercial importance or market positioning.
IV. Analysis of Infringement Allegations
’961 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| modulating data packets at the transmitter using a first modulation scheme to obtain first data symbols; | The Accused Instrumentality modulates data using a first modulation scheme (e.g., QPSK, 16QAM, or 64QAM) as part of an initial HARQ transmission. | ¶18 | col. 9:14-16 |
| performing the first transmission by transmitting the first data symbols over a first diversity branch to the receiver; | The Accused Instrumentality transmits the initial data symbols over a first diversity branch to a receiver (e.g., an LTE base station). | ¶19 | col. 9:17-19 |
| modulating said data packets at the transmitter using a second modulation scheme to obtain second data symbols; | Upon a retransmission request, the Accused Instrumentality allegedly uses a second, distinct modulation scheme, described as an "Adaptive Re-transmission" with a different Modulation Coding Scheme (MCS). | ¶20 | col. 9:20-22 |
| performing the second transmission by transmitting the second data symbols over a second diversity branch to the receiver; | The Accused Instrumentality transmits the second data symbols over a second diversity branch during the HARQ retransmission. | ¶21 | col. 9:23-25 |
| diversity combining the demodulated data received over the first and second diversity branches... | A base station receiving transmissions from the Accused Instrumentality performs HARQ soft-combining of the data from the first and second transmissions. A diagram illustrates this soft-combining process. (Compl. p. 31). | ¶23 | col. 9:30-32 |
| ...wherein: the modulation schemes are 16 QAM and a number of log2 (M) modulation schemes are used. | The Accused Instrumentality allegedly uses 16QAM and 64QAM, which are log2(M) modulation schemes where M > 4. | ¶24 | col. 9:30-32 |
- Identified Points of Contention:
- Scope Question: Does the accused "Adaptive Re-transmission," which changes the "Modulation and Coding Scheme (MCS)" (Compl. ¶20), meet the claim limitation of using a "second modulation scheme"? The defense may argue that MCS is a broader concept that includes coding rates in addition to the constellation mapping, while the patent's specification focuses specifically on rearranging the constellation itself ('961 Patent, Figs. 1-2).
- Technical Question: The complaint relies on general technical standards for LTE to describe the accused functionality. A key question for the court will be what evidence demonstrates that the Noodoe EV G100 product specifically implements these optional and configurable features of the standard in an infringing manner.
’622 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| ...a higher order modulation scheme wherein more than two data bits are mapped onto one data symbol... | The Accused Instrumentality allegedly uses 16QAM (4 bits per symbol) and 64QAM (6 bits per symbol), which are higher-order schemes. A table from a technical website is referenced to support this. (Compl. p. 41). | ¶32 | col. 7:38-42 |
| receiving at the transmitter the repeat request issued by the receiver to retransmit the data packets in case the data packets of the first transmission have not been successfully decoded; | The complaint alleges the Accused Instrumentality receives a repeat request (a NAK) from the base station when data is unsuccessfully decoded, triggering a retransmission. This is supported by a physical-layer model diagram. (Compl. p. 51). | ¶35 | col. 8:1-5 |
| modulating, in response to the received repeat request, said data packets at the transmitter using a second mapping of said higher order modulation scheme... | In response to the NAK, the Accused Instrumentality allegedly uses a second mapping, described as an "Adaptive Re-transmission" with a different MCS. A screenshot describes this adaptive process. (Compl. p. 53). | ¶36 | col. 8:6-10 |
| ...wherein: the first and second mapping of said higher order modulation schemes are pre-stored in a memory table. | The complaint alleges that the modulation schemes are decided by a MAC Scheduler and are pre-stored in a memory table, referencing a generic physical-layer model diagram. | ¶40 | col. 8:22-24 |
- Identified Points of Contention:
- Technical Question: Claim 1 explicitly requires the transmitter to receive a repeat request and modulate in response. The infringement theory relies heavily on diagrams of the general LTE HARQ process. The plaintiff will need to provide evidence that the accused product itself, not just the network it operates on, performs this specific sequence of actions.
- Scope Question: The claim requires that mappings are "pre-stored in a memory table." The complaint points to a general LTE diagram indicating that modulation schemes are decided by a scheduler (Compl. ¶40, p. 70). This raises the question of whether this general architectural feature satisfies the specific "pre-stored in a memory table" limitation as construed in light of the patent's specification.
V. Key Claim Terms for Construction
The Term: "modulation scheme" ('961 Patent) / "mapping" ('622 Patent)
- Context and Importance: These terms are central to the invention. The infringement case hinges on equating the accused product's alleged change in "Modulation and Coding Scheme (MCS)" with the patents' requirement for a different "modulation scheme" or "mapping." Practitioners may focus on this term because LTE's MCS parameter includes both the modulation order (e.g., 16QAM) and the channel coding rate, whereas the patent specification appears to focus narrowly on changing the bit-to-symbol constellation pattern.
- Intrinsic Evidence for a Broader Interpretation: The patent states the invention's objective is to improve performance by "applying different signal constellation mappings" to average bit reliabilities, which could arguably encompass any change in transmission parameters (including MCS) that achieves this result ('961 Patent, col. 2:18-23).
- Intrinsic Evidence for a Narrower Interpretation: The detailed description and figures provide specific examples of changing the bit-mapping order within the same constellation (e.g., comparing FIG. 1 and FIG. 2, which both depict 16-QAM but with different bit assignments). This could support a narrower construction limited to constellation rearrangement, excluding changes to the coding rate.
The Term: "diversity branch"
- Context and Importance: The claims require transmitting symbols over first and second "diversity branches." The complaint alleges infringement via HARQ, where a retransmission occurs at a later time. The interpretation of "diversity branch" will determine if a simple temporal retransmission qualifies.
- Intrinsic Evidence for a Broader Interpretation: The patent's background explicitly lists "Time Diversity" as a known diversity technique, which involves mapping a signal onto "different interleaving sequences" ('961 Patent, col. 1:39-40). This may support construing a subsequent HARQ retransmission as transmission on a second time-diversity branch.
- Intrinsic Evidence for a Narrower Interpretation: The specification also provides examples of spatial diversity, such as using different antennas or transmission sites ('961 Patent, col. 1:26-32). A defendant could argue that the term requires physically distinct transmission paths and that a simple retransmission over the same physical channel at a later time is insufficient.
VI. Other Allegations
- Indirect Infringement: The complaint focuses on direct infringement by the Defendant and does not plead specific facts or include separate counts to support claims of induced or contributory infringement.
- Willful Infringement: The complaint does not contain an explicit allegation of willful infringement. It alleges constructive notice of the patents through compliance with marking statutes but does not plead facts suggesting pre-suit knowledge or egregious conduct (Compl. ¶42).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central evidentiary issue will be one of technical proof: can the plaintiff's reliance on generic technical standards and third-party articles establish that the Defendant's Noodoe EV G100 product, specifically, practices the claimed methods, particularly the more detailed and conditional steps recited in the '622 Patent?
- A key legal issue will be one of definitional scope: can the terms "modulation scheme" and "mapping," which the patent specification illustrates through specific constellation rearrangements, be construed broadly enough to read on the accused product's alleged change of the entire "Modulation and Coding Scheme (MCS)," which also involves the channel coding rate?
- For the '622 Patent, the case may turn on a narrow point of claim construction and proof: what evidence will be required to show that the accused device uses mappings that are "pre-stored in a memory table," as explicitly required by the claim, and is the evidence from a general architectural diagram sufficient to meet this burden?