DCT
1:20-cv-05745
Swirlate IP LLC v. VeriFone Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Swirlate IP LLC (Texas)
- Defendant: Verifone, Inc. (Delaware)
- Plaintiff’s Counsel: Direction IP Law
- Case Identification: 1:20-cv-05745, N.D. Ill., 09/28/2020
- Venue Allegations: Venue is alleged to be proper based on Defendant maintaining a place of business in the Northern District of Illinois and allegedly committing acts of infringement within the district.
- Core Dispute: Plaintiff alleges that Defendant’s Verifone V400m payment terminal infringes two patents related to methods for improving data reliability in wireless communication systems using Automatic Repeat reQuest (ARQ) techniques.
- Technical Context: The patents address methods for improving the reliability of data sent over noisy wireless channels by systematically varying the bit-to-symbol mapping (constellation) for retransmitted data packets.
- Key Procedural History: The complaint notes that U.S. Patent No. 7,567,622 is a continuation of the application that resulted in U.S. Patent No. 7,154,961. It also references statements made during the prosecution of the '622 patent to distinguish the invention from prior art, emphasizing the benefits of averaging communication reliabilities and reducing data traffic.
Case Timeline
| Date | Event |
|---|---|
| 2002-10-18 | Earliest Priority Date for '961 and '622 Patents |
| 2006-12-26 | U.S. Patent No. 7,154,961 Issued |
| 2009-07-28 | U.S. Patent No. 7,567,622 Issued |
| 2020-09-28 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,154,961 - "Constellation Rearrangement for ARQ Transmit Diversity Schemes"
- Patent Identification: U.S. Patent No. 7,154,961, "Constellation Rearrangement for ARQ Transmit Diversity Schemes," issued December 26, 2006. (Compl. ¶9).
The Invention Explained
- Problem Addressed: In wireless communication systems employing higher-order modulation (e.g., 16-QAM), the individual bits mapped to a single transmission symbol can have different levels of reliability. Conventional ARQ schemes that simply retransmit data do not address this imbalance, which can lead to degraded decoder performance. (’961 Patent, col. 2:1-12).
- The Patented Solution: The invention proposes improving performance at the receiver by applying different signal constellation mappings for initial transmissions and subsequent ARQ retransmissions. By using a second, distinct modulation scheme for a retransmitted packet, the bit reliabilities are effectively averaged when the receiver combines the transmissions, improving the likelihood of a correct decoding. (’961 Patent, col. 2:18-29; Abstract).
- Technical Importance: This method seeks to enhance data transmission robustness in challenging wireless environments, a key objective in the development of reliable mobile communication standards. (Compl. ¶11).
Key Claims at a Glance
- The complaint asserts at least independent claim 1. (Compl. ¶16).
- Essential elements of claim 1 include:
- An ARQ re-transmission method in a wireless system with a first transmission and a second based on a repeat request.
- Modulating data packets with a first modulation scheme for the first transmission over a first diversity branch.
- Modulating the same data packets with a second modulation scheme for the second transmission over a second diversity branch.
- Demodulating the received data at the receiver using the respective schemes.
- Diversity combining the demodulated data.
- A concluding "wherein" clause specifies that "the modulation schemes are 16 QAM and a number of log₂(M) modulation schemes are used."
U.S. Patent No. 7,567,622 - "Constellation Rearrangement for ARQ Transmit Diversity Schemes"
- Patent Identification: U.S. Patent No. 7,567,622, "Constellation Rearrangement for ARQ Transmit Diversity Schemes," issued July 28, 2009. (Compl. ¶26).
The Invention Explained
- Problem Addressed: The ’622 Patent shares its specification with the ’961 Patent and addresses the same problem of unequal bit reliabilities in higher-order modulation schemes. (Compl. ¶28; ’622 Patent, col. 2:1-12).
- The Patented Solution: The solution is functionally identical to that of the ’961 Patent: using different bit-to-symbol mappings for initial transmissions and retransmissions. The claims of the ’622 Patent are structured differently, focusing on the process initiated "in response to the received repeat request" and requiring the modulation schemes to be "pre-stored in a memory table." (’622 Patent, Claim 1).
- Technical Importance: As with the parent patent, this method aims to improve data reliability, with prosecution history statements noting an advantage in reducing overall data traffic compared to prior art that always transmitted redundant data. (Compl. ¶30).
Key Claims at a Glance
- The complaint asserts at least independent claim 1. (Compl. ¶31).
- Essential elements of claim 1 include:
- An ARQ re-transmission method using a higher-order modulation scheme where more than two bits are mapped to a symbol.
- Modulating data packets with a first mapping to create first data symbols for a first transmission.
- Receiving a repeat request from the receiver.
- In response to the request, modulating the data packets with a second mapping to create second data symbols.
- In response to the request, performing a second transmission with the second data symbols.
- Demodulating and diversity combining the received data.
- A concluding "wherein" clause specifies that "the first and second mapping of said higher order modulation schemes are pre-stored in a memory table."
III. The Accused Instrumentality
Product Identification
- The Verifone V400m payment terminal. (Compl. ¶16).
Functionality and Market Context
- The complaint alleges the Verifone V400m is a wireless device that implements an HARQ (Hybrid ARQ) method for data transmission over an LTE network. (Compl. ¶17).
- It is alleged to use higher-order modulation schemes such as 16QAM and 64QAM. (Compl. ¶18).
- The complaint asserts that, upon receiving a negative acknowledgement (NAK), the device "enables a second mapping of a higher order modulation scheme (i.e., an adaptive re-transmission having a different Modulation Coding Scheme (MCS) than the one used for HARQ transmission)." (Compl. ¶20).
- Allegations regarding market context are not detailed, but Verifone is a prominent supplier of electronic payment and point-of-sale systems.
- No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’961 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| An ARQ re-transmission method in a wireless communication system wherein data packets are transmitted... using a first transmission and at least a second transmission based on a repeat request... | The Accused Instrumentality allegedly uses an HARQ method in an LTE network involving a transmission and retransmission based on a repeat request (NAK). | ¶17 | col. 1:56-63 |
| modulating data packets at the transmitter using a first modulation scheme to obtain first data symbols; | The device allegedly uses 16QAM and/or 64QAM to obtain first data symbols for an LTE 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 device allegedly transmits data symbols over a first diversity branch using multi-antenna processing that maps signals to available antenna ports. | ¶19 | col. 1:30-32 |
| modulating said data packets at the transmitter using a second modulation scheme to obtain second data symbols; | Upon a repeat request, the device allegedly "enables a second mapping of a higher order modulation scheme (i.e., an adaptive re-transmission having 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 device allegedly transmits second data symbols over a second or later diversity branch using multi-antenna processing. | ¶21 | col. 9:23-25 |
| diversity combining the demodulated data received over the first and second diversity branches... | A base station used with the device allegedly performs diversity combining, such as Hybrid ARQ soft-combining of data from multiple received antenna ports. | ¶23 | col. 9:28-30 |
| wherein: the modulation schemes are 16 QAM and a number of log₂(M) modulation schemes are used. | The device allegedly uses 16QAM and 64QAM, which the complaint asserts are log₂(16) and log₂(64) modulation schemes, respectively. | ¶24 | col. 9:30-32 |
- Identified Points of Contention:
- Technical Question: Does the accused product's use of a different "Modulation and Coding Scheme (MCS)" for retransmission constitute the use of a "second modulation scheme" as required by the claim? The analysis will likely focus on whether a change in coding rate (part of MCS) without an explicit change in the bit-to-symbol constellation map (like that shown between Fig. 1 and Fig. 2 of the patent) meets this limitation.
- Scope Question: How should the phrase "a number of log₂(M) modulation schemes" be interpreted? The complaint suggests this broadly covers M-ary QAM schemes. A court may need to determine if the phrase has a more specific technical meaning that limits the claim's scope.
’622 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| An ARQ re-transmission method... using a higher order modulation scheme wherein more than two data bits are mapped onto one data symbol... | The device allegedly uses 16QAM (4 bits/symbol) and 64QAM (6 bits/symbol) in an HARQ method. | ¶32 | col. 2:2-5 |
| modulating data packets at the transmitter using a first mapping of said higher order modulation scheme to obtain first data symbols; | The device allegedly performs a higher-order data modulation (16QAM/64QAM) using a first mapping to obtain first data symbols. | ¶33 | col. 7:44-49 |
| receiving at the transmitter the repeat request issued by the receiver to retransmit the data packets... | The device allegedly receives a repeat request (e.g., a NAK) from the receiver when data packets are not successfully decoded. | ¶35 | col. 1:59-63 |
| modulating, in response to the received repeat request, said data packets... using a second mapping of a higher order modulation scheme... | In response to a NAK, the device allegedly "enables a second mapping of a higher order modulation scheme (i.e., an adaptive re-transmission having a different Modulation Coding Scheme (MCS) than the one used for transmission)". | ¶36 | col. 7:59-col. 8:2 |
| performing, in response to the received repeat request, the second transmission by transmitting the second data symbols over a second diversity branch... | In response to a NAK, the device allegedly transmits second data symbols over a second or later diversity branch. | ¶37 | col. 8:1-3 |
| wherein: the first and second mapping of said higher order modulation schemes are pre-stored in a memory table. | The device allegedly uses higher-order modulation schemes that are "pre-stored in a memory table such as those schemes used by a MAC scheduler." | ¶40 | col. 8:65-col. 9:4 |
- Identified Points of Contention:
- Technical Question: Similar to the '961 Patent, a key question is whether changing the MCS is equivalent to using a "second mapping" that rearranges the constellation as described in the specification.
- Scope Question: Does a MAC scheduler's set of available, dynamically-selected transmission formats meet the "pre-stored in a memory table" limitation? A court may need to decide if this requires a static look-up table of specific constellation patterns (as depicted in patent Figure 5) or if it can be read more broadly to cover the set of schemes available to a scheduler.
V. Key Claim Terms for Construction
For both the '961 and '622 Patents
- The Term: "second modulation scheme" (’961 Patent) / "second mapping" (’622 Patent)
- Context and Importance: These terms are central to the novelty of the invention. The infringement theory hinges on equating the accused product's alleged change in Modulation and Coding Scheme (MCS) for a retransmission with the use of a distinct "scheme" or "mapping." Practitioners may focus on this term because the core technical benefit of the patent—averaging bit reliabilities—is achieved by this specific change.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the invention's idea as "applying different signal constellation mappings to the available distinguishable transmit diversity branches and ARQ (re-) transmissions." (’961 Patent, col. 2:19-22). A party could argue this encompasses any change that results in a different bit-to-symbol treatment upon retransmission, including an MCS change.
- Evidence for a Narrower Interpretation: The patent provides specific examples of different mappings where the bit order is explicitly changed (e.g., Mapping 1 vs. Mapping 2, where bits i₁ and i₂ are swapped). (’961 Patent, col. 7:20-24, Figs. 1-2). A party could argue the term is limited to this type of explicit constellation rearrangement, which provides a predictable averaging of reliabilities, rather than any change in coding rate.
For the '622 Patent
- The Term: "pre-stored in a memory table"
- Context and Importance: This limitation defines how the different mappings are made available to the transmitter. The complaint alleges this is met by schemes available to a MAC scheduler. The validity of this infringement theory depends on the construction of this term.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states that the sequence of patterns can be "pre-stored in the transmitter and the receiver or are signalled by transmitter to the receiver prior to usage." (’622 Patent, col. 9:4-6). This could support a view that any pre-defined set of available schemes, even if selected dynamically, meets the limitation.
- Evidence for a Narrower Interpretation: Figure 5 of the patent explicitly depicts a "table 15" that stores a plurality of "signal constellation patterns #0 . . . #n," suggesting a static, indexed lookup structure. (’622 Patent, Fig. 5; col. 8:65-col. 9:1). A party could argue the term should be limited to such a structure, not the more complex, algorithm-driven selection of schemes by a modern LTE MAC scheduler.
VI. Other Allegations
The complaint does not contain counts for indirect or willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of technical and definitional scope: Can the terms "second modulation scheme" and "second mapping" be construed to cover a change in the "Modulation and Coding Scheme" (MCS) used for a retransmission in an LTE system? The resolution will depend on whether this alleged change in the accused device performs the specific function of constellation rearrangement to average bit reliabilities as taught by the patents.
- A second central question will concern claim construction: Does a modern MAC scheduler's set of available, dynamically selected transmission schemes satisfy the '622 patent's requirement that mappings be "pre-stored in a memory table"? The case may turn on whether this is limited to a static lookup table or can encompass a more functional, pre-defined set of options.
- Finally, a key evidentiary question will be whether Plaintiff can prove, beyond the general allegations based on product datasheets and industry standards, that the Verifone V400m's internal software and hardware actually operate in the manner required by the asserted method claims.