CommPlex Systems LLC v. Teldat Sau

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: CommPlex Systems LLC (New Mexico)
  • Defendant: Teldat, Sau. (Spain)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-01166, E.D. Tex., 11/26/2025
• Venue Allegations: Venue is alleged to be proper because the defendant is a foreign corporation, and the complaint asserts that acts of infringement occurred in the district.
• Core Dispute: Plaintiff alleges that Defendant’s unnamed products infringe a patent related to systems for transmitting and receiving digital data using multiple orthogonal frequencies.
• Technical Context: The technology at issue involves methods for increasing the rate and efficiency of digital data transmission over wireless channels by encoding data onto multiple, distinct carrier frequencies.
• Key Procedural History: The complaint does not mention any prior litigation, licensing history, or administrative proceedings related to the patent-in-suit.

Case Timeline

Date	Event
2006-10-30	’900 Patent Priority Date
2011-01-04	’900 Patent Issue Date
2025-11-26	Complaint Filing Date

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

U.S. Patent No. 7,864,900 - "Communication system for sending and receiving digital data"

The Invention Explained

• Problem Addressed: The patent's background section describes limitations of conventional Frequency Shift Keying (FSK) data transmission systems, where inaccuracies in determining the center frequency can lead to a "distorted mark/space ratio in the demodulated data," causing transmission errors (Compl. Ex. 1, ’900 Patent, col. 2:60-64).
• The Patented Solution: The invention proposes a communication system that uses multiple orthogonal frequencies, where groups of data bits are represented by simultaneously transmitting a specific combination of frequencies from a larger available set (’900 Patent, Abstract). This "Multiple Orthogonal locked frequencies Narrow Band Frequency Shift Keying (Mary-NBFSK)" approach aims to increase the amount of data transmitted per unit of bandwidth (’900 Patent, col. 4:8-14). A transmitter encodes data into frequency combinations using a look-up table, and a receiver decodes the received frequencies back into the original data (’900 Patent, Fig. 7, Fig. 9).
• Technical Importance: The patent asserts that this method achieves a higher code density and requires less hardware and power compared to systems that use multiple parallel, individually coded binary FSK channels (’900 Patent, col. 4:15-23).

Key Claims at a Glance

• The complaint alleges infringement of "one or more claims" and refers to "Exemplary '900 Patent Claims" identified in an attached Exhibit 2, which was not provided with the filed complaint (Compl. ¶11, ¶16). For the purpose of analysis, the first independent claim is summarized below.
• Claim 1: A communication system comprising:
  • A transmitter and a receiver
  • A general binary coded Orthogonal Frequency-Division Multiplexing (OFDM) carrier scheme between the transmitter and receiver to increase code density and data rate
  • A plurality of narrow band carrier frequencies that are orthogonal and transmitted in a binary code
  • The narrow band carrier frequencies include a narrow band separation between the orthogonal carriers

III. The Accused Instrumentality

Product Identification

• The complaint does not identify any accused products by name. It refers generally to "Exemplary Defendant Products" that are identified in charts within an Exhibit 2, which was not provided with the filed complaint (Compl. ¶11, ¶16).

Functionality and Market Context

• The complaint does not provide sufficient detail for analysis of the accused instrumentality's functionality or market context. It alleges only that the "Exemplary Defendant Products practice the technology claimed by the '900 Patent" (Compl. ¶16). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint incorporates infringement allegations by reference to claim charts in an external Exhibit 2, which was not filed with the complaint (Compl. ¶16-17). The complaint itself does not contain specific factual allegations mapping claim elements to features of an accused product. The narrative infringement theory is limited to the assertion that the "Exemplary Defendant Products incorporated in these charts satisfy all elements of the Exemplary '900 Patent Claims" (Compl. ¶16).

Identified Points of Contention

• Lacking specific infringement allegations, a court's analysis would likely focus on several foundational questions.
  • Technical Questions: A primary question will be whether discovery provides evidence that the accused products utilize a "general binary coded Orthogonal Frequency-Division Multiplexing carrier scheme" as required by Claim 1. The specific method of how data is encoded onto carrier frequencies and decoded by a receiver will be a central point of technical inquiry.
  • Scope Questions: A potential dispute may arise over the scope of "narrow band carrier frequencies" and whether the accused products operate with frequency separations that fall within the patent's teachings, such as the "separation between orthogonal carriers of the order of 0.1 MHz" mentioned in the specification (’900 Patent, col. 9:5-8).

V. Key Claim Terms for Construction

• The Term: "Orthogonal Frequency-Division Multiplexing carrier scheme"
• Context and Importance: This term appears in the preamble of independent claim 1 and describes the core architecture of the claimed system. Its construction will be critical, as the infringement case depends on whether the defendant's technology can be properly characterized as an "OFDM carrier scheme."
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: Plaintiff may argue the term should be read broadly in light of the specification's description of its system as a "Multiple Orthogonal locked frequencies Narrow Band Frequency Shift Keying (Mary-NBFSK) system" (’900 Patent, col. 4:8-11), suggesting the claim term encompasses various multi-carrier orthogonal systems.
  • Evidence for a Narrower Interpretation: Defendant may argue that "OFDM" is a well-established term of art with a specific technical meaning that requires certain features (e.g., use of an Inverse Fast Fourier Transform to generate signals) not present in its products. The patent's own distinction from other FSK systems could be used to argue for a definition limited to the specific embodiments disclosed (’900 Patent, col. 1:15-2:62).

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement of infringement, stating that Defendant distributes "product literature and website materials inducing end users...to use its products in the customary and intended manner that infringes the '900 Patent" (Compl. ¶14).
• Willful Infringement: The complaint does not explicitly use the term "willful." However, it alleges that service of the complaint "constitutes actual knowledge of infringement" (Compl. ¶13). This allegation may form the basis for a claim of post-filing willful infringement and a request for enhanced damages if infringement is found.

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

Based on the complaint and patent, the litigation will likely revolve around two central questions for the court:

1. A question of definition: How should the term "Orthogonal Frequency-Division Multiplexing carrier scheme" be construed? The outcome will depend on whether the court defines it broadly to encompass a range of multi-carrier orthogonal systems like the one described in the patent, or narrowly as a specific technical standard that the accused products may not practice.
2. An evidentiary question of operation: As the complaint lacks specific factual allegations, a core issue will be whether the plaintiff can, through discovery, produce sufficient technical evidence to demonstrate that the accused products, in their actual operation, use "a plurality of narrow band carrier frequencies" that are "orthogonal" and "transmitted in a binary code" to represent data as required by the asserted claims.