By Michael Borella –

Eligibility wins at the Federal Circuit are scarce enough that any decision finding a claim to survive § 101 is worth a read. Constellation Designs, LLC v. LG Electronics Inc. is worth two reads, because the panel managed to do something more useful than affirm or reverse across the Board. Confronted with four patents drawn to the same basic invention, the Federal Circuit held one group of claims ineligible and a second group eligible, in a single opinion, and explained why. The result is about as clean a side-by-side of result-oriented claiming and specific-implementation claiming as one is likely to find (even though the difference between these approaches is blurrier in practice than the Court suggests).
By way of reminder, Alice v. CLS Bank Int’l sets up the familiar two-step eligibility inquiry. At step one, a court asks whether the claim is directed to a patent-ineligible concept such as an abstract idea. If it is, then at step two the court searches the claim, element by element and as an ordered combination, for an inventive concept that amounts to significantly more than the abstract idea itself.
The Technology
The patents concern digital communication systems, such as those that carry over-the-air television signals. A transmitter maps groups of bits to symbols and sends them across a noisy channel. Then, a receiver demodulates, demaps, and decodes them back into bits. The set of possible symbols is called a constellation, typically drawn as points on a plane, where each point corresponds to a unique bit pattern.
For years, the conventional wisdom held that capacity was maximized by spacing constellation points as far apart as possible, that is, by maximizing the minimum distance between points. The inventors took a different approach. Rather than optimizing for the minimum distance, they optimized non-uniform (unequally spaced) constellations for a measure called parallel decode (PD) capacity, which compares the information going into the mapper at one end of the channel with the information coming out of the demapper at the other. The payoff was a constellation that delivered a given capacity at a lower signal-to-noise ratio than a conventional minimum distance based design. Counterintuitively, the inventors found that the best results sometimes came from letting constellation points be on top of one another.
One feature of the record looms over the eligibility analysis. An inventor conceded that they did not invent the communication hardware, did not invent the use of non-uniform constellations, and did not even invent the idea of optimizing non-uniform constellations for a particular characteristic. The patents themselves cite an earlier reference optimizing a non-uniform constellation for PD capacity to achieve a shaping gain. That framing mattered to the panel when considering the scope of the claims.
The Claims
Constellation asserted nine claims across four patents, and the panel sorted them into two groups. The first, which it called the optimization claims, comprises claims in U.S. Patent Nos. 8,842,761 and 10,693,700. Claim 17 of the ‘761 patent is representative:
17. 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 likelihoods of symbols in a QAM symbol constellation from the demodulated signal;
a decoder that is configured to estimate decoded bits from the likelihoods generated by the demapper using an LDPC code; and
wherein 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 dmin.[1]
The second group, the constellation claims, comprises claims in U.S. Patent Nos. 11,019,509 and 11,018,922. Claim 21 of the ‘509 patent is representative:
21. 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.
Claim 17 recites a constellation “optimized for capacity using parallel decode capacity” to achieve a stated objective. Claim 21 recites a constellation with particular structural properties – unequally spaced points, distinct labels, and at least two points sharing a location. This distinction was determinative to the court.
The Eligibility Decision
The District Court had granted summary judgment that all of the asserted claims were eligible, on the theory that they recited a technical solution to a technical problem. The Federal Circuit agreed in part and disagreed in part.
The Court held that claim 17 is directed to the abstract idea of optimizing a constellation for PD capacity. The problem was breadth. The claim recites that the constellation is optimized for PD capacity to reach a particular result, namely a given capacity at a reduced SNR relative to a minimum distance based approach, but it does not recite how that optimization is accomplished. The panel invoked the venerable O’Reilly v. Morse and its more recent descendant ChargePoint v. SemaConnect, both of which look dimly on claims drafted so that they capture every means of achieving a result rather than a particular way of achieving it. Claim 17, the Court reasoned, covers all manners of optimizing a constellation based on one known characteristic, capacity, and one known capacity measure, PD capacity, and thus is drawn to an abstract idea.
Notably, the specification was not short on technical detail. It describes an iterative process, illustrated in Figure 5, for selecting the points and labeling of a geometrically shaped constellation. But the optimization claims do not recite that process, and the court reaffirmed the unforgiving rule that the § 101 inquiry focuses on the claim language and that details left in the specification cannot be imported to rescue a claim that does not recite them. At step two, the court found no inventive concept, observing that Constellation’s asserted inventive concept was the abstract idea itself, and that the company’s reliance on novelty and on LG’s failed obviousness challenges conflated the §§ 102 and 103 inquiries with the search for something significantly more. Claim 17, and the optimization claims with it, were held ineligible.
The constellation claims fared differently, and the Court resolved them at step one without ever reaching step two. Rather than claiming the objective of optimization, claim 21 recites specific structural constraints on the constellation. The points are unequally spaced, bearing different labels, and with at least two occupying the same location. The panel treated this as a concrete implementation of a technological solution to a technological problem, the problem being the capacity constraints of conventional constellations and the solution being a particular class of non-uniform constellations with overlapping point locations. Because the claim recited enough specificity and structure, it was not directed to an abstract idea, and the inquiry ended there. The constellation claims are eligible.
Analysis
The reason this case is interesting is that it isolates the eligibility inquiry better than most. Both groups of claims are based on the core innovation, that optimizing non-uniform constellations for PD capacity yields better performance at lower SNR. What differs is not the invention but the drafting. The optimization claims tried to capture the invention at the level of its goal, reciting a constellation “optimized for capacity using parallel decode capacity”, and in doing so claimed just the result. Under Morse and ChargePoint, claiming the result without how to achieve it is claiming in the abstract. The constellation claims captured the same invention at the level of its output, reciting the structural aspects of the constellation, and in doing so claimed a particular solution.
Still, there is an irony worth dwelling on. The “how” that the optimization claims lacked was not missing from the patents at all. It was present in the specification and the drawings. But a disclosure is not a claim, and the Federal Circuit is generally unwilling to read the specification’s language into claims that do not recite it. That is a harsh rule and is not new, but few cases illustrate its bite as plainly as this one, where the eligible and ineligible claims were litigated in the same case before the same panel.
Nonetheless, Thales Visionix Inc. v. United States, which we covered when it issued in 2017, makes for an uneasy comparison. Thales upheld a single-step method claim reciting only “determining an orientation of an object relative to a moving reference frame” based on signals from two inertial sensors mounted on the object and the frame. That is at least as result-oriented as a constellation “optimized for capacity using parallel decode capacity,” yet the Court found it eligible at step one by leaning on the specification’s account of why the underlying sensor configuration was unconventional. Here, the Court held that a disclosed-but-unclaimed technique counts for little. The two cases are not easily reconciled, and the friction is the sharper because this panel cited Thales for its step-one analysis and because Judge Stoll, who wrote this opinion, was on the Thales panel.
Also, when viewed against the record, the ineligibility of the optimization claims starts to look like the Court’s answer to claims that it regarded as scarcely distinguishable from the prior art but insulated from an easy dismissal under §§ 102 and 103 by fact-finding of lower tribunals. The breadth that doomed the optimization claims is breadth relative to the prior art, the very concern that animates novelty and obviousness, and the panel’s refrain that Constellation’s asserted inventive concept “was the abstract idea itself” reads at points less like a holding about eligible subject matter than like a finding that the gap between the claims and the prior art was too small.
Patent eligibility has long been the tool of choice for disposing of a patent a court does not believe in, precisely because it can reach that result on the pleadings or on summary judgment without the evidentiary discipline §§ 102 and 103 demand. Thales may simply be a case where the court believed in the invention while here it did not. That is not a principle one can put in a treatise, but it may explain this outcome.
Further, the Court’s reliance on preemption is a curious yardstick, because every valid patent claim preempts something.[2] That is what a claim is – a boundary that excludes others from practicing what falls inside it. Every single granted claim preempts all uses and objects that meet its limitations. The question can never be whether a claim preempts, only whether it preempts too much, which is exactly the judgment that § 101 was never designed to make and supplies no metric for making. The eligible constellation claims preempt every non-uniform constellation with unequally spaced points, distinct labels, and at least two coincident locations, which is hardly a narrow swath. What separated them from the optimization claims was not the quantity of preemption but the Court’s gut feeling that they claimed a thing rather than a goal. If that is the real distinction, and the analysis above suggests it is, then preemption is doing rhetorical rather than analytical work.
Indeed, after 12 years of post-Alice head scratching, it seems that one could replace the entire patent eligibility test with squinting at a claim and pronouncing whether it is “just too broad” in the subjective view of the beholder.[3] We would at least be spared the pretense that Morse and ChargePoint are supplying anything more than a framework to support an educated guess. It is a strange body of law that operates on intuition while insisting that it operates on doctrine, but here we are.
For practitioners, the lesson at hand is about drafting claims. When the inventive contribution is a way of producing a particular structure, claim the structure with the constraints and parameters that distinguish it, rather than the aspirational outcome that motivated it. A claim that recites just the goal of achieving a result invites a Morse problem. A claim that recites how the goal is achieved gives a court something concrete to hold. If the drafter decides to draft a result-driven independent claim anyway, at least one of its dependents should recite the “how” and not just the “what.”
None of this resolves the deeper incoherence in § 101, of course. But within the rules as they are, Constellation Designs is a rare decision that shows where the line between eligibility and ineligibility (a lightly drawn and dotted line, at best) is roughly located.
Constellation Designs, LLC v. LG Electronics Inc. (Fed. Cir. 2026)
Panel: Circuit Judges Lourie and Stoll and District Judge Oetken
Opinion by Circuit Judge Stoll
[1] Here, dmin refers to the minimum distance.
[2] Again, we get to blame the Supreme Court for this mess, as they introduced the notion of preemption into the § 101 analysis without providing substantive guidance as to how it should be used.
[3] This is not an academic or hyperbolic criticism. Many, many times I have interviewed USPTO examiners and the only rationale that they could give me for their § 101 rejection of a claim is that it was “too broad.”









