Digital Modulation Patents: Who Leads, Where the Gaps Are 2026
- Filing has cooled since its 2018 peak. 134 families filed that year against 108 in 2017 and just 96 at the 2022 midpoint — this is a maturing claim space, not a growing one.
- Six major assignees show zero filings in the latest year. Qualcomm, Samsung, Huawei, LG, Ericsson and ZTE all register 0 in the most recent tracked year, several with a -100% YoY drop, though publication lag understates the true recent count.
- The most-cited prior art predates the current filing wave by decades. The top-cited record, US5282222A on OFDM spread-spectrum multiple access, carries 1,062 citations — a reminder that citation weight favours foundational filings, not current activity.
Filing growth compares 2021 (106 records) with 2024 (74) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 2,528 records in scope (CR5), not by the ranked leaders only.
A dense, narrowing claim space built on decades-old foundations
Digital modulation patenting concentrates overwhelmingly in H04L (digital information transmission), which touches nearly the entire dataset, with meaningful secondary activity in H04B transmission hardware, H04J multiplexing and H03M coding. Filing volume peaked in 2018 and has trended down or flat since, a pattern consistent with a field where the core constellation-mapping and adaptive-modulation techniques are already well claimed rather than one still being actively opened up.
The most-cited records in the corpus — spread-spectrum multiple access and ultra-wideband communication patents from the 1990s — sit well outside the 2015-2026 filing window this landscape tracks, meaning current filers are building on, and designing around, art that is now old enough to be broadly enforceable or already expired in key jurisdictions.
Filing trend and technology composition
2,528 published families across the 2015-2026 window, concentrated in a handful of IPC subclasses and receiving offices, with the most recent year understated by publication lag.
Filings declined from a 2018 peak
From 108 families in 2017, filings rose to a peak of 134 in 2018, held near the 96 mark by the 2022 midpoint, and fell sharply toward the 2026 cut-off (7, partial year) — a flat-to-declining trajectory typical of a technology whose foundational claim territory is already occupied.
H04L dominates; H04B and H04J trail
H04L (digital information transmission) appears in 2,507 of 2,528 records, effectively defining the field. H04B (general transmission, 691) and H04J (multiplex communication, 263) form a secondary tier, with H04W wireless networks (255), H03M coding (230), and smaller counts in H04N video, H03K pulse technique and H03D demodulation marking narrower adjacent branches.
Shares are the percentage of the 2,528 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Digital Modulation Schemes (QAM/PSK) with Eureka
This page is one run against one query. Ask Eureka your own question about digital modulation schemes (qam/psk) and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited foundational art
Digital modulation method and apparatus (Huawei, 2017)
The filing addresses moving constellation points within a rectangular QAM constellation diagram, working across the four quadrants of the coordinate plane to redefine symbol mapping for a rectangular constellation generated by quadrature amplitude modulation of a data bit stream.Abstract text is condensed from the original filing; see the full record for complete claim language.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5282222A | Method and apparatus for multiple access between transceivers in wireless communications using OFDM spread sp… | 1,062 |
| 2 | US5677927A | Ultrawide-band communication system and method | 740 |
| 3 | US6008703A | Digital compensation for wideband modulation of a phase locked loop frequency synthesizer | 472 |
| 4 | US4495619A | Transmitter and receivers using resource sharing and coding for increased capacity | 452 |
| 5 | US6031862A | Ultrawide-band communication system and method | 381 |
| 6 | US6069899A | Home area network system and method | 292 |
| 7 | US6470055B1 | Spectrally efficient FQPSK, FGMSK, and FQAM for enhanced performance CDMA, TDMA, GSM, OFDN, and other systems | 275 |
| 8 | US6005894A | AM-compatible digital broadcasting method and system | 249 |
| 9 | US6757334B1 | Bit rate agile third-generation wireless CDMA, GSM, TDMA and OFDM system | 237 |
| 10 | US6088368A | Ethernet transport facility over digital subscriber lines | 223 |
Citation counts reward age within a searched corpus; treat this table as a map of influential prior art, not of current commercial activity.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three read-throughs from the trend, the IPC mix and the citation table that matter more than any single ranking.
The wave has already crested
Filing peaked in 2018 and has declined toward the 2026 cut-off. Because publication lags filing by roughly 18 months, the last one to two years understate true activity, but the multi-year decline from the 2018 peak through the 2022 midpoint of 96 is a real trend, not an artefact of the lag.
Digital transmission is the field's spine
Nearly every record in the corpus sits in H04L, with H04B transmission hardware and H04J multiplexing forming the next tier. Smaller counts in H04N, H03K and H03D mark adjacent branches — video pictorial transmission, pulse logic, and demodulation circuitry — where modulation art intersects other disciplines but is filed far less densely.
Foundational art predates the tracked window
The five most-cited records in this corpus were filed well before 2015, led by OFDM spread-spectrum and ultra-wideband patents. Current filers are working in the shadow of expired or near-expired foundational claims rather than contesting fresh territory.
Major filers have gone quiet — on paper
Qualcomm, Samsung, Huawei, LG, Ericsson and ZTE each show zero filings in the latest tracked year, several down -100% YoY. Given the ~18-month publication lag, this reflects the reporting window as much as a real halt, but it does mean the visible ranking is built on older filings.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to digital modulation schemes (qam/psk), with the prior art for and against each one.
A concentrated top tier over a long tail
Filing office data and co-assignee pairs point to a small set of large telecom and electronics filers working alongside university and research-institute partners, with commercial-scale activity now visible mainly in the older part of the record set.
US and EPO lead office of filing
The United States (920) and Europe (434) account for the largest shares of receiving-office activity, with China (298), WIPO/PCT (247), India (95) and Japan (85) forming a secondary tier — a filing footprint consistent with global handset and infrastructure telecom strategy rather than a single-region play.
University-industry pairs cluster in Korea
The strongest co-assignee link pairs a major Korean electronics manufacturer with a university technology-licensing office, and a second pair links a Korean research institute with another university partner — a pattern of sponsored academic research feeding directly into commercial filings.
Visible activity has shifted away from top-ranked filers
Every major assignee tracked for recent-year momentum shows zero filings in the latest year. That does not mean these organisations have exited the field — publication lag alone can explain much of it — but it does mean the current top-of-table ranking reflects filings from several years back, not this year's R&D.
| Assignee | Recent year | YoY |
|---|---|---|
| Qualcomm Incorporated | 0 | -100% |
| Samsung Electronics Co., Ltd. | 0 | — |
| Huawei Technologies Co., Ltd. | 0 | — |
| LG Electronics Inc. | 0 | — |
| Telefonaktiebolaget LM Ericsson | 0 | -100% |
| ZTE Corporation | 0 | -100% |
| Electronics and Telecommunications Research Institute (ETRI) | 0 | — |
| Motorola, Inc. | 0 | — |
Where to take this analysis
The dataset points to a mature core and a thinner set of adjacent branches. The next steps depend on whether the goal is freedom-to-operate or a new filing strategy.
Map claims against the most-cited prior art
Before drafting new constellation-mapping or adaptive-modulation claims, check them against the foundational OFDM and ultra-wideband patents that dominate the citation table — several are old enough that their enforceable scope, or lack of it, materially changes freedom-to-operate.
Explore prior art in EurekaWatch the assignees that went quiet
Zero recent-year filings at several major telecom assignees could reflect publication lag, a strategic pivot, or a shift to trade secret. Track their adjacent filings in related IPC classes to tell which.
Track assignee activity in EurekaTest the under-claimed branches
Thin filing counts in H03D, H03K and H04N overlaps suggest lower prior-art density for new claims that combine modulation techniques with those domains.
Run a white space search in EurekaCommon questions on digital modulation patents
The ranking is led by a small group of major telecom and electronics manufacturers, based on family counts across the 2,528 records in this corpus. However, several of the top-ranked assignees show zero filings in the latest tracked year, so the current leaderboard reflects filings accumulated over the 2015-2026 window rather than this year's activity. Because publication lags filing by roughly 18 months, recent filings from any assignee may not yet be visible in the count.
No — filings peaked in 2018 at 134 and have declined since, falling to 96 by the 2022 midpoint and further toward the 2026 cut-off. This is a flat-to-declining trend rather than a growth trend. The decline should be read as the field's core claim territory becoming well occupied, not necessarily as declining commercial interest in the underlying technology.
Start with H04L (digital information transmission), which covers 2,507 of the 2,528 records in this dataset and functions as the field's core classification. Then check H04B (transmission hardware, 691 records) and H03M (coding and code conversion, 230 records), since adaptive modulation claims frequently cross into both. Narrower adjacent classes — H04N for video applications, H03K for pulse-logic circuits, and H03D for demodulation — are worth checking if the claim touches those domains specifically.
That Huawei filing claims a specific method for moving constellation points within a rectangular QAM constellation diagram across the four quadrants of the coordinate plane, so it constrains that particular symbol-remapping approach rather than QAM constellation design broadly. Anyone designing a new constellation scheme should read its specific claim scope directly rather than assume it covers all rectangular-constellation modification techniques. Because it published in 2017, its priority date and prosecution history in each jurisdiction should be checked before relying on any freedom-to-operate conclusion.
The thinner IPC counts — H03D demodulation and frequency conversion at 42 records, H03K pulse technique at 44, and H04N pictorial communication overlap at 84 — suggest lower filing density than the H04L/H04B core. A first claim in these adjacent branches, for example combining adaptive modulation with pulse-logic circuit implementation, is likely to face less crowded prior art than a claim filed squarely in constellation mapping or bit-error-rate optimisation within H04L.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
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Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.