Eligibility Issues Explained: Constellation Designs, LLC

On April 28, 2026, the Court of Appeals for the Federal Circuit issued an opinion in Constellation Designs, LLC v LG Electronics Inc.¹ One of several issues in the opinion relates to patent eligibility under 35 USC 101. The opinion analyzed two representative claims: claim 17 of U.S. Patent No. 8,842,761 and claim 21 of U.S. Patent No. 11,019,509.

One conclusion from the opinion is that a claim that is described in a result-oriented way is more likely to be found patent ineligible than a claim that relies on structure.

The Optimization Claims

Claim 17 was determined to be representative of the plurality of claims referred to in the decision as the optimization claims:

A digital communication system, comprising:

• a receiver configured to receive signals transmitted via a communication channel using a QAM symbol constellation; wherein the receiver comprises:
  • a demodulator configured to demodulate the signal received via the communication channel;
  • a demapper configured to estimate the likelihoods of symbols in a QAM symbol constellation from the demodulated signal;
  • decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper using an LDPC code; and herein, the QAM symbol constellation is a geometrically spaced symbol constellation optimized for capacity using parallel decode capacity that provides a given capacity at a reduced signal-to-noise ratio compared to a QAM signal constellation that maximizes d_min.

The decision begins by summarizing the most recent Supreme Court guidance on 35 USC 101 patent eligibility:

To determine whether a patent claims ineligible subject matter, the Supreme Court has established a two-step framework. First, we must determine whether the claims at issue are directed to a patent-ineligible concept such as an abstract idea [step one]. Second, if the claims are directed to an abstract idea, we must “consider the elements of each claim both individually and ‘as an ordered combination’ to determine whether the additional elements ‘transform the nature of the claim’ into a patent-eligible application.” [step two]. To transform an abstract idea into a patent-eligible application, the claims must do “more than simply stat[e] the [abstract idea] while adding the words ‘apply it.’” 

In the step one analysis, the Court decided that claim 17 was directed to a patent-ineligible concept, in this case an abstract idea. Specifically, the claim recites that the QAM symbol constellation is “optimized” for PD (parallel decode) capacity to achieve a particular result: capacity at a reduced signal-to-noise ratio compared to conventional QAM signal constellations that maximize d_min. The Court determined that this was an “important and distinguishing element of the claim”. Furthermore, the Court concluded that the feature is defined in a result orientedresult-oriented way, i.e., reciting the intended result without reciting how to achieve the intended result, i.e., a constellation “optimized” for PD capacity. The Court then concluded that the claim is directed toat an abstract idea under step one of the Alice test, at least in part, because it is directed to all ways of achieving the recited result.

The decision relied on an old Supreme Court decision O’Reilly v Morse. In Morse, the Supreme Court “upheld claims related to the details of Samuel Morse’s invention of the electromagnetic telegraph, but invalidated a claim for the use of ‘electromagnetism, however developed for marking or printing intelligible characters, signs, or letters, at any distances.’” The Court [in Morse] expressed concern that such a broad claim would cover any application of printing at a distance via electromagnetism regardless of whether those applications used the invention in the patent. Morse’s invalidated claim encompassed all solutions for achieving a desired result and was “drafted in such a result-oriented way that [it] amounted to encompassing the ‘principle in the abstract’ no matter how implemented.”

In the present case, the Court concluded that claim 17 “covers all manners and ways of optimizing a constellation based on one of a limited number of known characteristics of constellations—capacity—and one of a limited number of known capacity measures—PD capacity.” The Court explained that, even if the specification includes enough detail to describe the invention, the patent eligibility inquiry must focus on the claim language, not the specification. Thus, the Court concluded that claim 17 is directed to an abstract idea under step one of the Alice test.

At step two of the Alice inquiry, the Court recognized that one must consider the elements of each claim both individually and “as an ordered combination” to determine whether the additional elements ”transform the nature of the claim” into a patent-eligible application. Where a claim is directed to an abstract idea, the claim “must include ‘additional features’ to ensure ‘that the [claim] is more than a drafting effort designed to monopolize the [abstract idea].’” These additional features cannot simply be “well-understood, routine, conventional activities” previously known to the industry. Instead, the inventive concept must be “sufficient to ensure that the patent in practice amounts to significantly more” than a patent on the abstract idea.

The Court concluded that the inventive concept of claim 17 is the application of the abstract idea itself and was not defined by any additional elements that transformed the claim into a patent-eligible claim. Therefore, claim 17 did not pass step two of the Alice test.

The Constellation Claims

In contrast to the “optimization” claims, the Court found that Claim 21 was patent eligible:

A communication system, comprising a receiver that receives signals via a communication channel having a channel signal-to-noise ratio (SNR), wherein the receiver uses a symbol constellation to transform the received signals into received bits, and the symbol constellation includes constellation points at a plurality of unique point locations, where:

• the plurality of unique point locations are unequally spaced;
• the constellation points each have a location and a different label; and
• the locations of at least two of the constellation points are the same.

Specifically, the Court concluded that claim 21 covers a concrete implementation of a technological improvement to solve a technological problem. The problem perceived by the patentee was overcoming the limits of constellation capacity to achieve better coding gains. See ’509 patent col. 1 l. 55–col. 2 l. 5. The specification explains that Constellation’s invention is the idea of “us[ing] signal constellations, which have unequally spaced (i.e.[,] ‘geometrically’ shaped) points,” in which “the locations of geometrically shaped points are designed to provide a given capacity measure at a reduced [SNR] compared to the SNR required by[ ]a constellation that maximizes d_min,” thus improving coding gains. ’509 patent col. 4 l. 65–col. 5 l. 8.

The inventors discovered that moving constellation points with the objective of maximizing capacity between the input of a mapper and the output of a demapper, instead of the output of the demodulator, led to the counterintuitive conclusion that “[t]he best thing to do is to start having points land on top of one another.” See, e.g., the last phrase of claim 21, which requires that the locations of at least two of the constellation points are the same.

The Court concluded that “claim 21 in its entirety is directed to solving a particular technological problem—overcoming capacity constraints to improve coding gains—using a particular technological solution—specific, non-uniform constellations with overlapping constellation point locations.”

Conclusions

The Constellation Designs opinion is helpful in that it contrasts two claims – one patent eligible and the other not patent eligible. As such, the opinion does provide some helpful thoughts in the patent eligibility analysis. However, it still fails to provide objective criteria in determining what is an abstract idea and what is needed to render an abstract idea patent eligible.

At step one of the Alice inquiry, one must determine whether the claims at issue are directed to a patent-ineligible concept. The Court recognized that “[a]t some level, ‘all inventions . . . embody, use, reflect, rest upon, or apply laws of nature, natural phenomena, or abstract ideas.’…Thus, at Alice step one, ‘it is not enough to merely identify a patent-ineligible concept underlying the claim; we must determine whether that patent-ineligible concept is what the claim is ‘directed to.’” 
In determining what claim 17 is directed to, the Court indirectly focused on what it considered to be the inventive concept of the claim, i.e., the feature that the inventors believed distinguished the claim over the prior art. In this case, the Court concluded that claim 17 is indeed directed to the abstract idea of “optimizing” a constellation for PD capacity.

A problem with this concept is that it is at odds with the well established principle that it is improper to look for the gist of a claim to determine patentability. Traditional jurisprudence emphasizes that a claim must be considered as a whole. Accordingly, the patent eligibility test of considering the inventive concept of the claim is contrary to the patentable concept of considering the claim as a whole. See, e.g., § 2103(C) of the Manual of Patent Examining Procedure, which states in part:

Finally, when evaluating the scope of a claim, every limitation in the claim must be considered. Examiners may not dissect a claimed invention into discrete elements and then evaluate the elements in isolation. Instead, the claim as a whole must be considered. See, e.g., Diamond v. Diehr, 450 U.S. 175, 188-89, 209 USPQ 1, 9 (1981) (“In determining the eligibility of respondents’ claimed process for patent protection under § 101, their claims must be considered as a whole. It is inappropriate to dissect the claims into old and new elements and then to ignore the presence of the old elements in the analysis. This is particularly true in a process claim because a new combination of steps in a process may be patentable even though all the constituents of the combination were well known and in common use before the combination was made.”).

In its patent eligibility analysis, the Court considered what it considered to be “the inventive concept” of the claim. The Court seems to have addressed the requirements of § 2103(C) by indicating that “Constellation points to no elements of the claims individually or as an ordered combination that transform the nature of the claim.” This implies that the Court did consider all of the elements of the claim as required by § 2103(C).

Based on this decision, drafters of claims should ensure that any claim that may arguably contain an abstract idea is directed toward using a particular technological solution to solve a particular technological problem.

Footnote

1. Constellation Designs, LLC v. LG Electronics Inc., 2024-1822 (Fed. Cir. Apr. 28, 2026)

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