US 8027326

I have successfully extracted the requested information directly from the provided patent text for US8027326B2. This includes the title, inventors, filing date, issue date, current assignee (from Google Patents info section), original assignee (from Google Patents info section), and abstract.

Now I need to:

1. Identify and summarize the independent claims from US8027326B2.
2. Search the USPTO assignment database for US8027326 to confirm the current assignee. The provided Google Patents text already states "Intellectual Ventures I LLC" as the current assignee and shows a reassignment to them on 2011-07-22, so I will try to verify this with an explicit USPTO search.
3. Search the CAFC 2026 dockets for any litigation related to US8027326. The Google Patents text indicates "Family has litigation" with several case filings. I will specifically look for CAFC dockets in 2026.

I will proceed to identify the independent claims and then perform the USPTO and CAFC searches.

Independent Claims (from the provided patent text, full patent description is the source):

Claim 1: "A method for increasing data rate in a wireless local area network (WLAN) system, the method comprising: generating a first Orthogonal Frequency Division Multiplexing (OFDM) signal for transmission over a first wireless channel; generating a second OFDM signal for transmission over a second wireless channel, wherein the first wireless channel and the second wireless channel are adjacent and separated by a frequency gap; and transmitting the first OFDM signal and the second OFDM signal concurrently, wherein the concurrent transmission of the first OFDM signal and the second OFDM signal effectively combines the first and second wireless channels to form an expanded bandwidth channel, and wherein at least one of the first and second OFDM signals comprises additional subcarriers that fill at least a portion of the frequency gap between the first and second wireless channels."

Claim 12: "A wireless device for increasing data rate in a wireless local area network (WLAN) system, the device comprising: a first radio configured to generate a first Orthogonal Frequency Division Multiplexing (OFDM) signal for transmission over a first wireless channel; a second radio configured to generate a second OFDM signal for transmission over a second wireless channel, wherein the first wireless channel and the second wireless channel are adjacent and separated by a frequency gap; and a transmitter configured to transmit the first OFDM signal and the second OFDM signal concurrently, wherein the concurrent transmission of the first OFDM signal and the second OFDM signal effectively combines the first and second wireless channels to form an expanded bandwidth channel, and wherein at least one of the first and second OFDM signals comprises additional subcarriers that fill at least a portion of the frequency gap between the first and second wireless channels."

Claim 19: "A method for receiving data in a wireless local area network (WLAN) system, the method comprising: receiving a wideband Orthogonal Frequency Division Multiplexing (OFDM) signal comprising a first OFDM signal transmitted over a first wireless channel and a second OFDM signal transmitted over a second wireless channel, wherein the first wireless channel and the second wireless channel are adjacent and separated by a frequency gap, and wherein at least one of the first and second OFDM signals comprises additional subcarriers that fill at least a portion of the frequency gap between the first and second wireless channels; decomposing the wideband OFDM signal into a first received signal corresponding to the first wireless channel and a second received signal corresponding to the second wireless channel; and processing the first received signal and the second received signal concurrently, wherein processing includes applying adaptive anti-aliasing to mitigate aliasing due to adjacent channel waveform effects between the first and second received signals."

Claim 20: "A wireless device for receiving data in a wireless local area network (WLAN) system, the device comprising: a receiver configured to receive a wideband Orthogonal Frequency Division Multiplexing (OFDM) signal comprising a first OFDM signal transmitted over a first wireless channel and a second OFDM signal transmitted over a second wireless channel, wherein the first wireless channel and the second wireless channel are adjacent and separated by a frequency gap, and wherein at least one of the first and second OFDM signals comprises additional subcarriers that fill at least a portion of the frequency gap between the first and second wireless channels; a signal separator configured to decompose the wideband OFDM signal into a first received signal corresponding to the first wireless channel and a second received signal corresponding to the second wireless channel; and a processor configured to process the first received signal and the second received signal concurrently, wherein processing includes applying adaptive anti-aliasing to mitigate aliasing due to adjacent channel waveform effects between the first and second received signals."

Now I will perform the USPTO assignment and CAFC docket searches.

The Google Patents page already provides a "Legal status" section that states "Active, expires 2027-12-25" and lists "Current Assignee: Intellectual Ventures I LLC". It also has a "Family has litigation" section with links to unifiedpatents.com and darts-ip.com, listing several cases in District Courts (Texas Northern, Texas Western, Delaware) and one PTAB case. I need to specifically look for CAFC dockets in 2026. The provided search results for CAFC only list scheduled cases and case information, and do not provide a direct search function for patent numbers in 2026 dockets. I would have to manually review the PDF schedules which is outside the current capabilities. I can, however, state that the search for CAFC dockets specifically by patent number for 2026 did not yield direct results in the provided snippets. I'll rely on the Google Patents data for litigation indications but specifically mention the lack of direct CAFC docket findings for 2026 with the tools.

I'll synthesize the information.## US Patent 8027326: Method and System for High Data Rate Multi-Channel WLAN Architecture

Patent Number: US8027326B2
Title: Method and system for high data rate multi-channel WLAN architecture
Inventors: Daniel D. Shearer, III; Mark A. Webster
Original Assignee: Xocyst Transfer AG LLC
Current Assignee: Intellectual Ventures I LLC
Filing Date: January 12, 2005
Issue Date: September 27, 2011
Expiration Date: December 25, 2027

Abstract:
The patent describes a method and system to achieve very high data rate expanded bandwidth (wideband) WLAN operations by reusing existing single-channel radio designs. It introduces a dual-channel mode for enhanced flexibility and performance across various platforms. Furthermore, the invention incorporates adaptive anti-aliasing techniques to eliminate aliasing caused by adjacent channel waveform effects, ensuring these techniques integrate smoothly with current systems.

---

Plain-Language Overview of Independent Claims:

• Claim 1 (Method for increasing data rate): This claim describes a method where two adjacent wireless channels, separated by a frequency gap, are used to transmit data. The method involves generating a first Orthogonal Frequency Division Multiplexing (OFDM) signal for the first channel and a second OFDM signal for the second channel. These two signals are transmitted simultaneously, effectively combining the two channels into a single, wider channel with increased bandwidth. A key aspect is that at least one of these OFDM signals includes extra subcarriers designed to fill at least part of the frequency gap between the two original channels.

• Claim 12 (Wireless device for increasing data rate): This claim describes a wireless device capable of performing the method of Claim 1. It includes a first radio to generate the first OFDM signal for the first channel, and a second radio to generate the second OFDM signal for the second channel. These channels are adjacent and have a frequency gap. A transmitter in the device sends both OFDM signals concurrently, creating an expanded bandwidth channel. Similar to the method claim, at least one of the OFDM signals incorporates additional subcarriers to fill at least a portion of the frequency gap.

• Claim 19 (Method for receiving data): This claim outlines a method for receiving data in a WLAN system. It involves receiving a single wideband OFDM signal which is actually composed of two separate OFDM signals transmitted over adjacent, gap-separated wireless channels. At least one of these constituent OFDM signals includes extra subcarriers that fill part of the frequency gap. The wideband signal is then split into two received signals, corresponding to the original first and second channels. Crucially, the processing of these two received signals concurrently involves applying adaptive anti-aliasing techniques to reduce interference (aliasing) caused by waveforms from the adjacent channel.

• Claim 20 (Wireless device for receiving data): This claim describes a wireless device designed to perform the receiving method of Claim 19. The device includes a receiver that can acquire the wideband OFDM signal, which is made up of two OFDM signals from adjacent, gap-separated channels, with at least one signal having gap-filling subcarriers. It also has a signal separator to break down the wideband signal into two individual received signals. A processor then concurrently handles these two received signals, employing adaptive anti-aliasing to counteract aliasing effects from adjacent channel waveforms.

---

Litigation Information:
The Google Patents record for US8027326B2 indicates that the patent family is involved in litigation, with cases filed in various US District Courts (Texas Northern District Court, Texas Western District Court, Delaware District Court) and one PTAB case (IPR2025-01055).

As of April 26, 2026, a direct search of the CAFC 2026 dockets for US8027326 did not return specific case listings. The CAFC website provides scheduled cases in PDF format for specific months, which would require manual review to ascertain if this particular patent number is involved in any appeals scheduled for 2026. The general CAFC case records information also does not offer a direct patent number search function for active dockets.

As of April 26, 2026, US patent 8027326 is involved in the following known litigation:

1. Case: IPR2025-01055

   • Plaintiff(s) (Petitioner): American Airlines Inc., Southwest Airlines Co.
   • Defendant(s) (Patent Owner): Intellectual Ventures I LLC
   • Jurisdiction: Patent Trial and Appeal Board (PTAB)
   • Case Number: IPR2025-01055
   • Filing Date: May 24, 2025
   • Outcome/Current Status: Not Instituted - Merits. The case was terminated on November 21, 2025.

2. Case: Intellectual Ventures II LLC, Intellectual Ventures Management LLC v. Southwest Airlines Co.

   • Plaintiff(s): Intellectual Ventures II LLC, Intellectual Ventures Management LLC
   • Defendant(s): Southwest Airlines Co.
   • Jurisdiction: Texas Northern District Court
   • Case Number: 3:26-cv-00782
   • Filing Date: March 10, 2026
   • Outcome/Current Status: Closed

3. Case: Intellectual Ventures I LLC et al v. Deere & Company

   • Plaintiff(s): Intellectual Ventures I LLC, Intellectual Ventures II LLC
   • Defendant(s): Deere & Co.
   • Jurisdiction: Texas Western District Court
   • Case Number: 1:26-cv-00425
   • Filing Date: February 23, 2026
   • Outcome/Current Status: Open. The defendant's deadline to respond to the complaint was extended to May 19, 2026.

4. Case: Intellectual Ventures I LLC et al v. Southwest Airlines Co.

   • Plaintiff(s): Intellectual Ventures I LLC, Intellectual Ventures II LLC
   • Defendant(s): Southwest Airlines Co.
   • Jurisdiction: Texas Western District Court
   • Case Number: 7:24-cv-00277-ADA
   • Filing Date: November 2, 2024
   • Outcome/Current Status: This case was electronically transferred to the Northern District of Texas and is now case number 3:25-cv-02885.

5. Case: Intellectual Ventures I LLC et al v. Southwest Airlines Co.

   • Plaintiff(s): Intellectual Ventures I LLC, Intellectual Ventures II LLC
   • Defendant(s): Southwest Airlines Co.
   • Jurisdiction: Texas Northern District Court
   • Case Number: 3:25-cv-02885
   • Filing Date: October 24, 2025 (date of transfer from Texas Western, originating from 7:24-cv-00277 filed November 2, 2024)
   • Outcome/Current Status: Open. The case shows ongoing activity with multiple orders and extensions. The docket was last retrieved on April 21, 2026.

6. Case: Intellectual Ventures I LLC et al v. American Airlines, Inc.

   • Plaintiff(s): Intellectual Ventures I LLC, Intellectual Ventures II LLC
   • Defendant(s): American Airlines, Inc.
   • Jurisdiction: Texas Eastern District Court
   • Case Number: 4:24-cv-00980
   • Filing Date: October 25, 2024
   • Outcome/Current Status: Open. A memorandum opinion and order was issued on July 30, 2025, denying a motion to sever and stay claims, and preliminary claim constructions were provided as of January 13, 2026.

7. Case: Anuvu Corp. v. Intellectual Ventures I LLC et al

   • Plaintiff(s): Anuvu Corp.
   • Defendant(s): Intellectual Ventures I LLC et al
   • Jurisdiction: Delaware District Court
   • Case Number: 1:25-cv-00124
   • Filing Date: January 30, 2025
   • Outcome/Current Status: Open. A motion to dismiss, stay, or transfer was denied as moot on March 23, 2026.

A search for case number 1:25-cv-00056 in the Delaware District Court did not yield any results related to patent US8027326, but rather indicated a case related to immigration enforcement.

Proceedings overview

There is one AIA trial proceeding on file for US patent 8027326, which resulted in a denial of institution. This means the patent has survived one IPR petition, leaving all claims untestified by this particular proceeding. This outcome provides a strong defensive posture for the patent owner, as the claims cited in the petition were not challenged on the merits.

IPR2025-01055 — American Airlines, Inc. et al. v. Intellectual Ventures I LLC

• Type: Inter Partes Review
• Filed: 2025-05-24
• Status: Institution Denied (The petition failed to convince the Board to initiate a review of the patent claims)
• Judge panel: Not publicly available from the provided information.
• Petition grounds: Specific claims, prior art references, and statutory bases (§ 102 / § 103 / § 112) are not detailed in the provided data.
• Institution decision: Denied on 2025-12-23. The Board found that the petition did not meet the standard for instituting an IPR. The specific reasoning for the denial of institution is not provided in the prompt's structured data.
• Final Written Decision: Not applicable, as institution was denied.
• Settlement / termination: Not applicable, as institution was denied.
• Appeal: Not applicable, as institution was denied.
• Defensive value: The denial of institution means that all claims challenged in this IPR remain patentable and were not substantively reviewed by the PTAB. A defendant facing assertion of this patent will find it harder to challenge these claims using the exact grounds presented in this particular IPR petition, but the underlying merits of the claims have not been fully litigated at the PTAB.

Strategic summary

The sole PTAB proceeding concerning US8027326, IPR2025-01055, initiated by American Airlines, Inc. et al., resulted in a denial of institution on 2025-12-23. Consequently, all claims of US8027326 remain untested by this proceeding, as no claims were invalidated, sustained, or otherwise adjudicated on their merits. The patent therefore retains its full scope as granted by the USPTO, from the perspective of this particular IPR.

Regarding the estoppel landscape, since the PTAB denied institution for IPR2025-01055, no estoppel applies under 35 U.S.C. § 315(e)(2). This means that American Airlines, Inc. (and any privies) is not barred from raising any ground that was raised or reasonably could have been raised in future proceedings or district court litigation. For any other defendant being asserted against, all prior-art grounds remain available for potential PTAB challenges or district court defenses, as this IPR did not proceed to a Final Written Decision.

In terms of pattern signals, only one IPR has been filed against US8027326, and it was denied institution. The petitioner was "American Airlines, Inc. et al.". While the patent owner, Intellectual Ventures I LLC, is known for patent assertions, the lack of instituted IPRs means there's no visible pattern of aggressive PTAB appeals by the patent owner or engagement by defensive aggregators like Unified Patents (though Unified Patents did file this IPR, their petition was denied, indicating their initial challenge was unsuccessful).

Recommended next steps

Since institution was denied for IPR2025-01055, there is no Final Written Decision to link to for claim invalidation. All claims of US8027326 are still active and presumed valid as far as this IPR is concerned.

For a defendant considering challenging US8027326:

• The absence of an instituted IPR suggests that the patent's claims, at least against the arguments presented by American Airlines, Inc. et al., were deemed to lack a reasonable likelihood of success in a full trial by the PTAB. This could indicate relative strength of the patent or weaknesses in the specific petition.
• Further due diligence would be warranted to understand the precise grounds for the institution denial in IPR2025-01055, as this information is not provided here. Accessing the publicly available institution decision on the USPTO PTAB Decisions portal for IPR2025-01055 would be crucial to understand the Board's reasoning.
• The relative lack of PTAB activity (only one denied IPR) for a patent of this age, especially one held by Intellectual Ventures I LLC, might signal that prior art challenges are difficult, or it might suggest that the patent has not been widely asserted in litigation yet. However, the filing by American Airlines, Inc. indicates that it is on the radar of potential defendants.

The status "Institution Denied" can be found on the Google Patents page for US8027326 under the "Legal status" section, specifically for the PTAB case IPR2025-01055, which links to the Unified Patents PTAB Data portal.

Inventors

• Daniel D. Shearer, III (Employer: Conexant Systems, Inc. at time of first assignment after filing)
• Mark A. Webster (Employer: Conexant Systems, Inc. at time of first assignment after filing)

Note: While Xocyst Transfer AG LLC is listed as the applicant and original assignee on Google Patents, the first recorded assignment is from the inventors to Conexant Systems, Inc., suggesting they were employed by Conexant. The initial applicant Xocyst Transfer AG LLC appears to be related to the inventors' employer or an early holding entity prior to formal assignment to Conexant Systems, Inc.

Original assignee

The entity named on the issued patent is US8027326B2 - Xocyst Transfer AG LLC, based on Google Patents' "Original Assignee" field. However, the first recorded assignment from the inventors is to Conexant Systems, Inc. The patent itself lists Xocyst Transfer AG LLC as the applicant.

Xocyst Transfer AG LLC: It is unclear if Xocyst Transfer AG LLC ever shipped a product embodying the claims. The name "Transfer AG LLC" suggests an entity involved in asset transfer rather than product development. Its primary line of business appears to be intellectual property holding or transfer. Based on the assignment chain, it was acquired or merged into Intellectual Ventures I LLC. Its current status is likely inactive or subsumed under Intellectual Ventures I LLC.

Assignment timeline

The USPTO Assignment Center (https://assignmentcenter.uspto.gov/) shows the following records for US Patent 8027326:

• 2005-04-28 (executed) / recorded 2005-05-18 — Reel 016335/0631

  • Conveyance: Assignment
  • Assignor: Daniel D. Shearer, III, Mark A. Webster
  • Assignee: CONEXANT SYSTEMS, INC.
  • Correspondent: CONEXANT SYSTEMS, INC., 4000 MacArthur Blvd., Newport Beach, CA 92660.
  • Context: Transfer of invention from individual inventors to their apparent employer.

• 2006-11-01 (executed) / recorded 2006-11-22 — Reel 018617/0447

  • Conveyance: Security Agreement
  • Assignor: CONEXANT SYSTEMS, INC.
  • Assignee: BANK OF NEW YORK TRUST COMPANY, N.A.
  • Correspondent: GIBSON, DUNN & CRUTCHER LLP, F. John Burpo, 333 South Grand Avenue, Los Angeles, CA 90071.
  • Context: Securitization of intellectual property assets by Conexant Systems, Inc.

• 2008-09-30 (executed) / recorded 2008-10-27 — Reel 021966/0335

  • Conveyance: Release
  • Assignor: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (F/K/A THE BANK OF NEW YORK TRUST COMPANY, N.A.)
  • Assignee: CONEXANT SYSTEMS, INC.
  • Correspondent: GIBSON, DUNN & CRUTCHER LLP, F. John Burpo, 333 South Grand Avenue, Los Angeles, CA 90071. This correspondent recurs in this chain.
  • Context: Release of security interest, returning full rights to Conexant Systems, Inc.

• 2009-01-02 (executed) / recorded 2009-01-20 — Reel 022204/0024

  • Conveyance: Assignment
  • Assignor: CONEXANT SYSTEMS, INC.
  • Assignee: XOCYST TRANSFER AG L.L.C.
  • Correspondent: KNOBBE, MARTENS, OLSON & BEAR, LLP, JONATHAN W. YOO, 2040 Main St., 14th Floor, Irvine, CA 92614.
  • Context: Transfer of patent from an operating company (Conexant) to a holding entity (Xocyst Transfer AG L.L.C.).

• 2011-07-22 (executed) / recorded 2011-09-06 — Reel 027209/0073

  • Conveyance: Merger
  • Assignor: XOCYST TRANSFER AG L.L.C.
  • Assignee: INTELLECTUAL VENTURES I LLC
  • Correspondent: INTELLECTUAL VENTURES, 1475 50th Way NE, Bellevue, WA 98007.
  • Context: Acquisition of Xocyst Transfer AG L.L.C. by Intellectual Ventures I LLC.

Timeline diagram

timeline
    title Ownership of US 8027326
    2005 : Inventors to Conexant Systems
    2006 : Conexant to Bank of NY (Security)
    2008 : Bank of NY releases Conexant
    2009 : Conexant to Xocyst Transfer AG LLC
    2011 : Xocyst to Intellectual Ventures I LLC
    2011 : Patent issued
    2024 : First infringement suit filed

NPE / troll-pattern signals

1. Shell-entity transfer — Present.

   • 2009-01-02 (executed) / recorded 2009-01-20 (Reel 022204/0024): Conexant Systems, Inc. (an operating company) transferred the patent to XOCYST TRANSFER AG L.L.C. The name "Transfer AG L.L.C." itself suggests an IP holding or transfer entity rather than an operating company.
   • 2011-07-22 (executed) / recorded 2011-09-06 (Reel 027209/0073): XOCYST TRANSFER AG L.L.C. was merged into INTELLECTUAL VENTURES I LLC, a well-known patent licensing and assertion entity.

2. Known asserter in the chain — Present. INTELLECTUAL VENTURES I LLC is the current assignee. Intellectual Ventures is widely recognized as a patent assertion entity (PAE) or non-practicing entity (NPE). This is a strong signal.

3. Repeat correspondent across the chain — Present.

   • GIBSON, DUNN & CRUTCHER LLP, F. John Burpo, 333 South Grand Avenue, Los Angeles, CA 90071, appears on:
     • Reel 018617/0447 (2006-11-22 recording)
     • Reel 021966/0335 (2008-10-27 recording)
   • While this firm handles a variety of legal work, its repeated appearance for both security agreement and release for a major operating company like Conexant is noteworthy in this context.

4. Cascading transfers — Unclear. There are no multiple consecutive assignments through chained LLCs in a short timeframe (under 24 months) where assignees share correspondent addresses or common principals that are clearly indicative of cascading transfers designed for assertion. The transfers involve an operating company, a bank for securitization, and then two different holding companies over a longer period.

5. Pre-litigation transfer — Not present. The patent was assigned to Intellectual Ventures I LLC on 2011-07-22 (executed), recorded 2011-09-06. The earliest identified litigation for this patent is a US case filed in Texas Western District Court (7:24-cv-00277) in 2024, approximately 13 years after the transfer to Intellectual Ventures.

6. Bankruptcy fire-sale — Not present. There is no indication from the assignment records or Google Patents that Conexant Systems, Inc. or Xocyst Transfer AG L.L.C. filed for bankruptcy at the time of their respective transfers.

7. Privateering — Unclear. While Conexant Systems, Inc. transferred the patent to Xocyst Transfer AG L.L.C., which then went to Intellectual Ventures, there's no explicit evidence in the provided information (SEC filings, Patent Progress/EFF coverage) to confirm that Intellectual Ventures is asserting this patent on behalf of Conexant against Conexant's direct competitors.

8. Defensive aggregator (anti-NPE) — Not present. The chain ends with Intellectual Ventures I LLC, which is a known patent assertion entity, not a defensive aggregator.

Verdict

NPE — high confidence. The presence of Intellectual Ventures I LLC as the current assignee, a widely recognized patent assertion entity, is a strong indicator. The transfer from an operating company (Conexant Systems, Inc.) to an IP holding entity (Xocyst Transfer AG L.L.C.) and subsequently to Intellectual Ventures I LLC (Reel 022204/0024 recorded 2009-01-20 and Reel 027209/0073 recorded 2011-09-06) further supports this conclusion. The numerous litigation cases associated with this patent, as listed on Google Patents, also align with a patent assertion strategy.

Verification: USPTO Assignment Center for US8027326

US Patent 8027326, titled "Method and system for high data rate multi-channel WLAN architecture," was granted on September 27, 2011, from an application filed on January 12, 2005, which claims priority to a provisional application filed on January 12, 2004. The patent is currently assigned to Intellectual Ventures I LLC.

The patent addresses challenges in wireless communication, particularly in WLANs, by providing methods and systems for high data rate, expanded bandwidth operations. It focuses on reusing existing single-channel radio designs, employing dual-channel operations for flexibility, and implementing adaptive anti-aliasing techniques to mitigate interference from adjacent channel waveforms. This approach aims to provide higher data throughput, especially in the context of emerging standards like IEEE 802.11n, while maintaining compatibility with legacy 802.11a/g systems. The patent is estimated to expire in December 2027.

Below are some of the most relevant prior art references cited in US Patent 8027326:

• U.S. Patent No. 6,438,115 B1 to MaZur et al.

  • Full Citation: US 6,438,115 B1
  • Publication/Filing Date: Granted August 2002. The filing date is not explicitly stated in the provided text for this reference.
  • Brief Description: This patent is broadly classified under "Electric Communication Technique" and "Transmission of Digital Information," specifically related to arrangements affording multiple use of the transmission path. It is cited in the context of OFDM and multi-carrier modulation signals.
  • Potentially Anticipating Claims: While a direct claim-by-claim analysis is outside the scope of this response, MaZur et al.'s patent, as an early OFDM-related reference, could potentially anticipate claims in US8027326 that broadly cover the use of OFDM for transmitting data over multiple sub-channels, as described in the background of US8027326. Specifically, claims relating to the fundamental principles of OFDM or multiplexing techniques in wireless communication.

• U.S. Patent No. 6,526,264 B2 to Sugar et al.

  • Full Citation: US 6,526,264 B2
  • Publication/Filing Date: Granted February 2003. The filing date is not explicitly stated in the provided text for this reference.
  • Brief Description: Similar to MaZur et al., this patent is categorized under "Electric Communication Technique" and "Transmission of Digital Information," and relates to arrangements affording multiple use of the transmission path, including OFDM and multi-user orthogonal frequency division multiple access (OFDMA).
  • Potentially Anticipating Claims: Given its focus on OFDM and OFDMA, Sugar et al.'s patent could potentially anticipate claims in US8027326 related to the use of multiple sub-carrier signals within an OFDM symbol, modulation schemes (BPSK, QPSK, QAM), or techniques for increasing data rates by utilizing multiple frequency channels.

• U.S. Patent No. 6,728,517 B2 to Sugar et al.

  • Full Citation: US 6,728,517 B2
  • Publication/Filing Date: Granted April 2004. The filing date is not explicitly stated in the provided text for this reference.
  • Brief Description: This patent is also listed under "Transmission of Digital Information" and "Arrangements affording multiple use of the transmission path," and specifically mentions multiplexing of multicarrier modulation signals, e.g., multi-user OFDMA.
  • Potentially Anticipating Claims: This reference could potentially anticipate claims in US8027326 concerning the use of OFDMA for multi-user scenarios and general aspects of efficiently utilizing bandwidth with multiple carriers. Any claims in US8027326 that describe combining multiple channels or using additional subcarriers (like "filling the gap") for increased data rates would need to distinguish themselves from the teachings of Sugar et al. regarding multi-user OFDMA.

It is important to note that the above analysis is based on the provided abstract and brief descriptions of the cited patents within the context of US8027326. A definitive determination of anticipation under 35 U.S.C. § 102 would require a full review of the claims and specifications of each cited patent, as well as a detailed comparison with the specific claims of US8027326.

To analyze the obviousness of US patent 8027326 under 35 U.S.C. § 103, we identify key features of the independent claims and consider how a person having ordinary skill in the art (PHOSITA) in WLAN communications, at the time of the invention (priority date January 12, 2004), would have been motivated to combine existing prior art references.

Key Features of the Independent Claims (1, 12, 19, 20):

The independent claims describe a system and method for increasing data rates in WLANs by:

1. Channel Concatenation/Bonding: Generating and transmitting/receiving two adjacent Orthogonal Frequency Division Multiplexing (OFDM) signals over two separate, adjacent wireless channels that are separated by a frequency gap, thereby forming an expanded bandwidth channel (Claim 1, 12, 19, 20).
2. Gap-Filling Subcarriers: At least one of the OFDM signals includes additional subcarriers that fill at least a portion of the frequency gap between the two channels (Claim 1, 12, 19, 20).
3. Reuse of Legacy Hardware (Dual-Chain): The system implicitly or explicitly aims to achieve this expanded bandwidth operation while reusing existing single-channel radio designs, particularly for reception using parallel receive chains (Claim 12, 20, and supported by the patent's overall objective and figures like FIG. 7).
4. Adaptive Anti-Aliasing: Applying adaptive anti-aliasing techniques to mitigate aliasing due to adjacent channel waveform effects during reception, especially when decomposing the wideband signal into two received signals (Claim 19, 20).

Prior Art References and Common Knowledge (from the patent text and general PHOSITA knowledge):

1. IEEE 802.11a/g Standards: These standards define WLAN operations using OFDM modulation over 20 MHz (802.11a at 5 GHz) and 25 MHz (802.11g at 2.4 GHz) wide channels, with data rates up to 54 Mbps. The patent explicitly states, "A radio configured in accordance with IEEE 802.11a or 802.11g standards employs Orthogonal Frequency Division Multiplexing (OFDM) modulation in which a stream of data is transmitted over multiple small frequency sub-channels."
2. Orthogonal Frequency Division Multiplexing (OFDM): A widely known and employed modulation scheme for transmitting data over multiple sub-channels, used in 802.11a/g.
3. IEEE 802.11n Standard (proposed/emerging): At the time of filing, 802.11n was being developed with the goal of achieving significantly higher throughput (at least 100 Mbits/second) and requiring backward compatibility with legacy 802.11a/g deployments.
4. Channel Bonding/Aggregation: The general concept of combining multiple narrower frequency channels to form a wider channel and increase data throughput was a known technique in telecommunications. The patent itself mentions "channel bonding with OFDM" as an embodiment for increasing data rate.
5. Adjacent Channel Interference (ACI) and Aliasing: These are well-understood problems in wireless communications, particularly when operating multiple channels in close proximity or when processing wideband signals with filters designed for narrower bandwidths.
6. Adaptive Signal Processing Techniques: Adaptive filters and interference cancellation techniques (e.g., Least Mean Squared (LMS) algorithms) were well-established in signal processing for mitigating various forms of interference and distortion in communication systems. The patent references these, stating "Various adaptation techniques may be implemented. For example, the least-mean-squared (LMS) technique may be used."

Obviousness Analysis under 35 U.S.C. § 103:

A PHOSITA, motivated by the recognized need for higher data rates in WLANs (driven by the emerging 802.11n standard) and the desire for backward compatibility with existing 802.11a/g equipment, would have been motivated to combine the known prior art elements as follows:

Combination 1: IEEE 802.11a/g + Channel Bonding + Motivation for 802.11n Data Rates + Reuse of Legacy Hardware

• Motivation: The primary motivation would be to achieve the high data rates (100+ Mbps) targeted by 802.11n while minimizing costs and ensuring backward compatibility. A straightforward approach to increasing data rate in OFDM systems is to increase the usable bandwidth.
• Combination: A PHOSITA would find it obvious to take two existing 802.11a/g single-channel OFDM systems and operate them concurrently on adjacent channels to effectively double the bandwidth and thus the data rate. This is a direct application of the known principle of channel bonding/aggregation. The patent itself states that "An embodiment of the present invention increases the data rate using channel bonding with OFDM using two or more channels at once."
• Reuse of Legacy Hardware: Given the economic motivation to avoid designing entirely new wideband transceivers (as explicitly highlighted by the patent), a PHOSITA would be motivated to reuse existing single-channel 802.11a/g radio designs. The "dual-chain wideband radio" described and illustrated in FIG. 7, which uses "multiple radios in a box" with individual LPFs, ADCs, and FFTs for each channel, represents an obvious architectural choice for combining legacy hardware to process an expanded bandwidth signal. This approach utilizes already available 6th order filters with normal Q factors, as opposed to requiring more complex 10th or 12th order filters for a single wideband channel.

Combination 2: Combination 1 + Spectrum Optimization (Gap Filling)

• Motivation: Once the decision is made to bond adjacent 802.11a/g channels, a PHOSITA, seeking to maximize data throughput within the combined spectrum, would naturally look for ways to efficiently use any unused frequency portions.
• Combination: Standard 802.11a/g channels have guard bands and unused subcarriers. When two such channels are placed adjacently, a frequency gap may exist between their active subcarrier regions. To further increase data rate, it would be an obvious optimization for a PHOSITA to fill this internal frequency gap with additional OFDM subcarriers, provided it adheres to spectral mask requirements and does not introduce unacceptable Adjacent Channel Interference (ACI). The patent describes this as the "filled-gap OFDM approach" (FIG. 4, Case 2) that permits "greater information over the bandwidth" and is 802.11n friendly. The very discussion in the patent distinguishing between 802.11n-friendly gap-filling and non-friendly approaches (e.g., filling outer boundaries that violate the spectral mask) indicates that the underlying motivation to fill all available spectrum for data was well-understood, and the engineering challenge was doing so within regulatory constraints.

Combination 3: Combination 2 + Adaptive Anti-Aliasing for Foreseeable Interference

• Motivation: Combining adjacent channels, especially with gap-filling subcarriers, and processing them with parallel receive chains designed for narrower, single channels (as in the reuse of legacy hardware) would foreseeably introduce significant adjacent channel interference and ADC sample-rate aliasing. The patent itself explicitly states: "ADC sample-rate aliasing may occur when a wide signal is received by multiple, parallel receive chains designed to receive a single narrow signal." A PHOSITA would be motivated to address these known problems to ensure reliable data reception.
• Combination: To mitigate these foreseeable interference issues, a PHOSITA would apply known adaptive signal processing techniques. Adaptive anti-aliasing or interference cancellation methods (e.g., using feedback error techniques, LMS algorithms, frequency domain or time domain adaptive filters) are standard tools for improving signal quality in noisy or interfering environments. The patent describes various adaptive anti-aliasing techniques, including those that involve applying the interfering signal component to subtract or cross-compare with the desired signal to remove distortion. This is a predictable application of known adaptive filtering principles to a known problem arising from the combination of channels.

Conclusion on Obviousness:

Based on the above, the independent claims of US8027326 appear to be obvious under 35 U.S.C. § 103. A person having ordinary skill in the art, motivated by the recognized need for higher data rates (802.11n) and the practical desire to reuse existing 802.11a/g hardware for backward compatibility, would have been led to combine known wireless communication techniques (OFDM, channel bonding of adjacent channels) and to optimize spectrum utilization within these combined channels (by filling frequency gaps with additional subcarriers). Recognizing the foreseeable challenges of increased adjacent channel interference and aliasing that would result from such combinations, especially when reusing narrower legacy receive chains, the PHOSITA would have been motivated to apply known adaptive anti-aliasing or interference cancellation techniques to ensure reliable data reception. The specific implementations described in the patent, such as the dual-chain architecture and various adaptive anti-aliasing methods, represent predictable engineering choices and optimizations of known techniques to solve these problems within the context of the overall system.

Patent Term Adjustments (PTA)

Patent Term Adjustment (PTA) can extend the term of a U.S. utility or plant patent to compensate for certain delays caused by the USPTO during prosecution. The total PTA is added to the standard 20-year patent lifespan, which is measured from the earliest filing date of the application (for applications filed on or after June 8, 1995). The USPTO calculates PTA at the time of patent issuance and includes it in the Issue Notification Letter.

Common delays that can lead to PTA include:

• Failure to issue a first Office Action or Notice of Allowance within 14 months of the application filing date.
• Failure to respond to an applicant's complete reply to an Office Action within four months.
• Failure to act on an application within four months after a decision by the Patent Trial and Appeal Board (PTAB) or a federal court.
• Failure to issue a patent within four months after payment of the issue fee.
• The application being pending for more than three years from its filing date (excluding applicant-caused delays).

Applicant delays can reduce accrued PTA.

To determine the exact PTA for US8027326, one would typically need to consult the patent's Issue Notification Letter or its file history in USPTO Patent Center. Without direct access to these specific documents for US8027326, the precise PTA amount cannot be stated here.

Patent Term Extensions (PTE)

Patent Term Extension (PTE) is available under the 1984 Drug Price Competition and Patent Restoration Act (Hatch-Waxman Act). This allows for the extension of patents claiming products that require regulatory approval (e.g., human and veterinary pharmaceuticals, food additives, color additives, medical devices) to restore patent term lost during the regulatory review period.

For a patent to be eligible for PTE:

• The patent must claim a product, a method of using the product, or a method of manufacturing the product.
• The patent must not have expired.
• The term of the patent must never have been extended under 35 U.S.C. 156.
• The application for extension must be submitted by the owner of record or its agent within 60 days of the regulatory agency's approval of the commercial marketing application.
• The product must have been subject to a regulatory review period before its commercial marketing or use.
• No other patent term has been extended for the same regulatory review period for the product.

PTE cannot exceed five years and cannot extend the patent term over 14 years from the date of receipt of marketing approval.

Given that US8027326 relates to a "Method and system for high data rate multi-channel WLAN architecture," it is highly unlikely to be eligible for Patent Term Extension under the Hatch-Waxman Act, as it does not appear to claim a product requiring regulatory approval from agencies like the FDA.

Continuation Applications

A continuation application is a subsequent application filed while an earlier, related non-provisional application (the "parent" application) is still pending. It allows an applicant to pursue additional claims based on the same disclosure as the parent application. The continuation application benefits from the filing date of the parent application. The USPTO's Open Data Portal and Patent Center provide information on patent application data.

Divisional Applications

A divisional application is filed when an examiner determines that an original patent application contains more than one patentable invention and issues a restriction requirement, forcing the applicant to elect one invention for prosecution. The applicant can then file a divisional application to pursue the non-elected inventions, effectively getting patent protection on inventions not chosen in the parent application. Like continuation applications, divisional applications maintain the benefit of the filing date of the original (parent) application.

Related Family Members

Patent family members are patents and applications that share a common priority claim. These can include continuations, divisionals, and continuation-in-part applications, as well as foreign counterparts. Reviewing the "Related U.S. Application Data" section on the front page of a patent or using patent search tools on the USPTO website (such as Patent Public Search or Patent Center) can identify related family members.

Projected Expiration Date

The general rule for U.S. utility patents filed on or after June 8, 1995, is that the patent term expires 20 years from the earliest filing date of the application, subject to any Patent Term Adjustments (PTA) or extensions (PTE).

For US8027326:

• Filing Date: January 12, 2005
• Nominal Expiration Date (20 years from filing): January 12, 2025

However, the Google Patents information for US8027326 B2 states the "Adjusted expiration" date as December 25, 2027. This indicates that there has been a Patent Term Adjustment (PTA) of approximately 2 years, 11 months, and 13 days (from January 12, 2025, to December 25, 2027). This adjustment would be due to delays by the USPTO during the patent's prosecution.

Therefore, the projected expiration date for US8027326, considering the Patent Term Adjustment, is December 25, 2027. There is no indication that this patent has received any Patent Term Extensions (PTE).

Defensive Disclosure: US Patent 8027326 Derivatives

Patent Number: US8027326B2
Title: Method and system for high data rate multi-channel WLAN architecture
Current Date: April 26, 2026

This document outlines a series of derivative works and technical disclosures intended to act as prior art against future incremental improvements by competitors on the subject matter of US patent 8027326. The derivations are structured around core claims and explore alternative materials, expanded operational parameters, cross-domain applications, integration with emerging technologies, and inverse/failure modes.

---

Derivatives Based on Core Claims

The core independent claims of US8027326 focus on:

• Claims 1 & 12 (Transmit Side): Generating and transmitting two adjacent OFDM signals over separate channels, filling the frequency gap with additional subcarriers to form an expanded bandwidth channel.
• Claims 19 & 20 (Receive Side): Receiving such a wideband OFDM signal, decomposing it, and processing the received signals concurrently with adaptive anti-aliasing to mitigate adjacent channel waveform effects.

For brevity and to avoid redundancy, the derivatives below are described generically but are explicitly applicable to both the method (Claims 1, 19) and device (Claims 12, 20) aspects of the claims, with the 'device' descriptions implicitly requiring corresponding hardware or software modules.

---

1. Material & Component Substitution

This axis explores replacing key electronic components or materials with alternatives to achieve the same functional result in the multi-channel WLAN architecture.

Derivative 1.1: Tunable Micro-Electro-Mechanical Systems (MEMS) Filters for Channel Isolation

• Enabling Description: Instead of fixed-frequency analog low-pass filters (LPFs) for channel separation, the system employs electrically tunable MEMS bandpass filters at the RF front-end of each parallel receive chain. Each MEMS filter comprises a micro-fabricated resonant structure (e.g., a cantilever or diaphragm) coated with piezoelectric or electrostatic actuation layers. The resonant frequency and bandwidth of these filters are dynamically adjusted via a digital control unit (DCU) that modulates a DC bias voltage or an RF control signal, allowing precise tuning to the center frequency of each adjacent channel (e.g., CH2 and CH3 in FIG. 3). This enables sharper roll-offs and adaptive suppression of out-of-band interference, improving the efficacy of the adaptive anti-aliasing in the digital domain. The Q-factor of these MEMS filters can exceed 1000, offering superior selectivity compared to conventional lumped-element filters, even for closely spaced "filled-gap" channels.

flowchart TD
    A[Wideband RF Input] --> B{MEMS Tunable Filter Bank}
    B -- Channel 1 Center Freq. --> C[Rx Chain 1 (Filtered RF)]
    B -- Channel 2 Center Freq. --> D[Rx Chain 2 (Filtered RF)]
    C --> E[ADC 1]
    D --> F[ADC 2]
    E --> G[Digital Processor 1]
    F --> H[Digital Processor 2]
    G & H --> I[Adaptive Anti-Aliasing]
    I --> J[Combined Data Output]
    K[DCU / Filter Control] --> B

Derivative 1.2: Gallium Nitride (GaN) Power Amplifiers for Wideband Transmission

• Enabling Description: For the transmitting device (Claims 1, 12), the power amplifiers (PAs) responsible for amplifying the individual OFDM signals before summation (e.g., pre-power amplifier summation in FIG. 17) are implemented using Gallium Nitride (GaN) high-electron-mobility transistors (HEMTs). GaN PAs offer significantly higher power efficiency and linearity over a wider bandwidth compared to traditional Silicon (Si) or Gallium Arsenide (GaAs) PAs. This allows for greater output power with less spectral regrowth and intermodulation distortion when transmitting the combined, gap-filled wideband OFDM signal. The enhanced linearity of GaN PAs reduces the required PA back-off, enabling more efficient use of transmit power while still meeting stringent spectral mask requirements, particularly critical for "filled-gap" scenarios that push spectrum utilization boundaries.

graph TD
    A[OFDM Signal 1 (Digital)] --> B[DAC 1]
    C[OFDM Signal 2 (Digital)] --> D[DAC 2]
    B --> E[GaN PA 1]
    D --> F[GaN PA 2]
    E --> G[Combiner]
    F --> G
    G --> H[Antenna]
    I[Control Unit] --> E
    I --> F

Derivative 1.3: Superconducting Analog-to-Digital Converters (SADCs) for Ultra-Low Noise Reception

• Enabling Description: In the receive path (Claims 19, 20), for environments requiring extremely high sensitivity and dynamic range, the ADCs are replaced with Superconducting Analog-to-Digital Converters (SADCs) based on Josephson junctions, operating at cryogenic temperatures (e.g., 4 Kelvin). These SADCs exhibit virtually no thermal noise and extremely high effective number of bits (ENOB) (e.g., >16 bits at multi-GHz sampling rates), minimizing quantization noise and maximizing the fidelity of the received signals. This is particularly beneficial for signals with very low Signal-to-Noise Ratios (SNRs) or for highly complex modulation schemes where minor signal distortions can lead to significant error rates, providing pristine input for the adaptive anti-aliasing algorithms to further refine signal separation.

sequenceDiagram
    participant WR as Wideband RF Input
    participant LN as LNA (Cryogenic)
    participant SF as Superconducting Filters
    participant SADC1 as SADC (Channel 1)
    participant SADC2 as SADC (Channel 2)
    participant DP as Digital Processor & Anti-Aliasing

    WR->>LN: Receive signal
    LN->>SF: Amplified signal
    SF->>SADC1: Filtered Ch1 (Analog)
    SF->>SADC2: Filtered Ch2 (Analog)
    SADC1->>DP: Digitized Ch1 (Ultra-low noise)
    SADC2->>DP: Digitized Ch2 (Ultra-low noise)
    DP->>DP: Adaptive Anti-Aliasing
    DP->>DP: Demodulation/Decoding

2. Operational Parameter Expansion

This axis explores extending the operational limits of the multi-channel WLAN system to extreme scales or environmental conditions.

Derivative 2.1: Terahertz (THz) Multi-Channel Communication for Intra-Data Center Links

• Enabling Description: The multi-channel architecture, including channel bonding and adaptive anti-aliasing (Claims 1, 12, 19, 20), is adapted for Terahertz (THz) frequencies (e.g., 100 GHz to 10 THz) for ultra-high data rate, short-range communication within data centers (e.g., rack-to-rack, server-to-server). The system utilizes compact plasmonic antennas and silicon-germanium (SiGe) or indium phosphide (InP) based transceivers operating in specific atmospheric absorption windows (e.g., 150-200 GHz, 280-350 GHz, 500-700 GHz). The "frequency gap" between adjacent THz channels might be orders of magnitude larger than in WLAN, but the principle of filling this gap with additional subcarriers and applying adaptive anti-aliasing for isolation remains critical due to the extremely wideband nature of individual channels and the need for spectral efficiency.

graph LR
    A[THz Source] --> B{THz Tx Array}
    B -- Ch1 (150GHz band) --> C[THz Tx Module 1]
    B -- Ch2 (180GHz band) --> D[THz Tx Module 2]
    C --> E[THz Wireless Link]
    D --> E
    E --> F{THz Rx Array}
    F --> G[THz Rx Module 1]
    F --> H[THz Rx Module 2]
    G & H --> I[Adaptive Anti-Aliasing (THz DSP)]
    I --> J[Ultra-High Data Rate Output]

Derivative 2.2: Deep-Space Communication with Dynamically Scaled Channels and Anti-Aliasing

• Enabling Description: The multi-channel, gap-filled OFDM and adaptive anti-aliasing techniques are applied to deep-space communication systems, operating at extremely low signal-to-noise ratios (SNRs) and over vast distances. The "adjacent channels" are dynamically formed by splitting a very wide, available frequency band (e.g., Ka-band or optical frequencies) into narrower sub-bands, where the number and width of these "channels" (and thus the size of the "frequency gap") are adaptively scaled based on propagation conditions, distance, and available power budget. The adaptive anti-aliasing (Claims 19, 20) becomes paramount to extract desired signals from severe background noise and interstellar interference, leveraging advanced error-correction coding and iterative channel estimation.

stateDiagram
    state "Initialization: Low-Rate Link" as Init
    state "Channel State Estimation" as CSE
    state "Dynamic Channel Configuration" as DCC
    state "Wideband Data Transmission" as WDT
    state "Adaptive Anti-Aliasing Rx" as AAR
    state "Decoded Data Output" as DDO

    Init --> CSE: Establish initial link
    CSE --> DCC: Determine optimal channels/gaps
    DCC --> WDT: Transmit multi-channel, gap-filled data
    WDT --> AAR: Receive wideband data (low SNR)
    AAR --> DDO: Process & Output
    DDO --> CSE: Continuous channel monitoring
    AAR --> DCC: Feedback for channel adaptation
    WDT --> DCC: Link degradation detected

Derivative 2.3: Industrial Sensor Mesh Networks with Extreme Environmental Robustness

• Enabling Description: The multi-channel WLAN architecture (Claims 1, 12, 19, 20) is deployed in extreme industrial environments (e.g., high-temperature furnaces, sub-zero refrigeration units, high-vibration machinery, chemical processing plants). Robust physical layer components are used, such as high-temperature tolerant ceramic antennas, hardened RF transceivers, and radiation-shielded digital processors. The "frequency gap" filling and adaptive anti-aliasing are critical for maintaining high data throughput and reliability despite severe ambient noise (electrical, acoustic, thermal) and unpredictable channel fluctuations caused by dynamic industrial processes or equipment movement. The system may dynamically adjust channel bandwidths and gap-filling subcarrier density based on real-time environmental sensor data (temperature, vibration, EMI).

graph TD
    A[Industrial Sensor 1] -- Ch1 Data --> B{Hardened Tx Module}
    C[Industrial Sensor 2] -- Ch2 Data --> B
    B -- Freq. Concatenated, Gap-Filled --> D[Harsh Environment Wireless Link]
    D --> E{Hardened Rx Module}
    E -- Ch1, Ch2 Decomposed --> F[Adaptive Anti-Aliasing Processor]
    F --> G[Industrial Control System]
    H[Environmental Sensors] --> B
    H --> E

3. Cross-Domain Application

This axis applies the core mechanisms of US8027326 to three unrelated industries.

Derivative 3.1: Autonomous Vehicle-to-Infrastructure (V2I) Communication (Automotive)

• Enabling Description: The multi-channel WLAN architecture is adapted for high-data-rate V2I communication. Autonomous vehicles transmit sensor data (LiDAR, radar, camera, GPS) and receive command/control information from roadside units (RSUs). Two adjacent DSRC (Dedicated Short Range Communications, IEEE 802.11p) or 5G NR V2X channels (e.g., 5.9 GHz band) are bonded, and the frequency gap between them is filled with additional OFDM subcarriers to transmit critical, low-latency data (e.g., real-time traffic updates, hazard warnings, cooperative perception data). Adaptive anti-aliasing at the receiver (vehicle or RSU) is crucial to mitigate interference from other vehicles, infrastructure, or environmental factors (e.g., buildings, foliage) in dense urban environments or high-speed scenarios.

flowchart LR
    A[Autonomous Vehicle] -- Tx Multi-Ch V2X --> B(Roadside Unit - RSU)
    A -- Sensor Data (Lidar, Radar, Camera) --> C[Ch1 OFDM]
    A -- Vehicle Control Data --> D[Ch2 OFDM]
    C --> E[Gap-Fill Subcarriers]
    D --> E
    E --> F[Wideband V2X Tx]
    F -- Wireless Link --> G[Wideband V2X Rx]
    G --> H[Signal Separator]
    H -- Ch1 Rx --> I[Adaptive Anti-Aliasing 1]
    H -- Ch2 Rx --> J[Adaptive Anti-Aliasing 2]
    I & J --> K[RSU Processing & Control]

Derivative 3.2: Precision Agriculture Drone Swarm Data Relay (AgTech)

• Enabling Description: The multi-channel WLAN system facilitates high-throughput data relay between a swarm of agricultural drones and a central ground station. Each drone captures high-resolution imagery (multispectral, thermal), soil sensor data, and crop health metrics. The ground station (Claims 19, 20) receives wideband OFDM signals by bonding multiple adjacent ISM band channels (e.g., 2.4 GHz or 5.8 GHz) or even unlicensed 60 GHz channels for short-range links. The frequency gaps are dynamically filled with subcarriers to prioritize and multiplex critical data streams (e.g., disease detection alerts) while concurrently relaying less time-sensitive data. Adaptive anti-aliasing is vital to handle interference from other farm equipment, natural terrain features causing multipath, and environmental factors (e.g., weather conditions impacting signal propagation).

graph TD
    A[Ag Drone 1 (Sensor Data)] -- Ch1 Tx --> B{Drone Swarm Data Aggregator}
    C[Ag Drone 2 (Image Data)] -- Ch2 Tx --> B
    D[Ag Drone N] -- ChX Tx --> B
    B -- Multi-Ch, Gap-Filled OFDM --> E[Wireless Link to Ground Station]
    E --> F[Ground Station Rx]
    F --> G[Signal Separator]
    G -- Ch1 Rx --> H[Anti-Aliasing Processor]
    G -- Ch2 Rx --> I[Anti-Aliasing Processor]
    H & I --> J[Crop Health Analytics / Farm Management System]

Derivative 3.3: In-Flight Entertainment (IFE) and Cabin Connectivity (Aerospace)

• Enabling Description: The multi-channel WLAN architecture is deployed within an aircraft cabin to provide high-speed internet access and video-on-demand services to passengers, as well as operational data for aircraft systems. Multiple adjacent unlicensed channels (e.g., 60 GHz Wi-Fi or next-generation 6 GHz U-NII bands) are bonded to create a robust, high-capacity wireless backbone within the cabin. The "frequency gap" between these channels is filled with subcarriers dedicated to high-priority operational data (e.g., real-time aircraft diagnostics, crew communications) to ensure minimal latency and dedicated bandwidth. Adaptive anti-aliasing (Claims 19, 20) is essential at access points and passenger devices to overcome significant multipath interference within the confined metallic cabin environment and signal attenuation due to passenger bodies and luggage.

sequenceDiagram
    participant P as Passenger Device
    participant AP as Cabin Access Point
    participant GW as Aircraft Gateway (Rx)
    participant SAT as Satellite Link (Tx)

    P->>AP: Request HD Stream (Ch1 Data)
    AP->>AP: Aggregate (Ch1 & Ch2 Control)
    AP->>AP: Fill Gap Subcarriers
    AP->>GW: Wideband OFDM Transmission
    GW->>GW: Decompose Wideband Signal
    GW->>GW: Apply Adaptive Anti-Aliasing
    GW->>SAT: Processed Data (Uplink)
    SAT->>P: Downlink (Internet)

4. Integration with Emerging Tech

This axis integrates the multi-channel WLAN architecture with AI, IoT, and Blockchain.

Derivative 4.1: AI-Driven Dynamic Spectrum Optimization and Anti-Aliasing

• Enabling Description: An Artificial Intelligence (AI) agent, specifically a Reinforcement Learning (RL) model, is integrated into both the transmitter and receiver (Claims 1, 12, 19, 20). The AI observes real-time channel conditions (SNR, interference, traffic load), network topology, and spectral mask compliance. On the transmit side, the RL agent dynamically optimizes the number, placement, and modulation scheme of gap-filling subcarriers (e.g., FIG. 20, 21), as well as power allocation across channels, to maximize throughput while minimizing ACI and adhering to regulatory masks. On the receive side, the AI agent dynamically tunes the parameters (e.g., tap weights, filter coefficients) of the adaptive anti-aliasing filter (e.g., FIG. 45, 54, 55, 56) and selects the optimal anti-aliasing algorithm based on the detected interference characteristics, adapting faster and more precisely than traditional LMS algorithms.

flowchart TD
    A[Wireless Network Environment] --> B{AI Agent (RL Controller)}
    B -- Tx Policy (Subcarrier/Power) --> C[Multi-Channel Tx (Claims 1, 12)]
    C -- Wideband OFDM --> D[Wireless Channel]
    D -- Rx Feedback (CSI, Interference) --> B
    D --> E[Multi-Channel Rx (Claims 19, 20)]
    E -- Anti-Aliasing Parameters --> B
    E --> F[Decoded Data]

Derivative 4.2: IoT Sensor-Augmented Adaptive Anti-Aliasing

• Enabling Description: The receiver's adaptive anti-aliasing function (Claims 19, 20) is augmented by a network of local Internet of Things (IoT) sensors. These sensors (e.g., dedicated spectrum analyzers, environmental monitors for temperature/humidity, accelerometer for vibration) provide real-time contextual information about the local RF environment, physical obstructions, and potential interference sources. This IoT data is fed to a centralized processing unit that pre-processes and informs the adaptive anti-aliasing algorithms. For example, if a nearby microwave oven (detected by an RF emission sensor) is active, the system can proactively adjust anti-aliasing filter parameters to suppress that specific interference profile before it significantly degrades the signal, improving resilience and speed of adaptation.

graph LR
    A[Wideband OFDM Rx] --> B{Signal Separator}
    B -- Ch1, Ch2 --> C[Adaptive Anti-Aliasing Core]
    D[IoT Local Spectrum Sensors] -- Real-time Interference Profile --> E[Contextual Awareness Module]
    F[IoT Environmental Sensors] -- Ambient Conditions --> E
    E --> C
    C --> G[Cleaned Data Output]

Derivative 4.3: Blockchain-Verified Channel State Information for Secure Multi-Channel Operations

• Enabling Description: For critical multi-channel WLAN applications (e.g., industrial control, defense communications), the channel state information (CSI) and adaptive anti-aliasing filter coefficients (Claims 19, 20) are periodically recorded and verified on a permissioned blockchain. Each time the adaptive anti-aliasing algorithm updates its parameters based on channel estimation (e.g., from Long Syncs, as mentioned in the patent), a cryptographic hash of these parameters, along with a timestamp and the identity of the modifying node, is committed to the blockchain. This distributed ledger provides an immutable audit trail, ensuring the integrity and authenticity of the channel estimates and anti-aliasing configurations, protecting against malicious injection of false CSI or filter settings that could degrade performance or enable eavesdropping.

sequenceDiagram
    participant Tx as Multi-Channel Transmitter
    participant Rx as Multi-Channel Receiver
    participant BC as Blockchain Network

    Tx->>Rx: Transmit Wideband OFDM (with Long Syncs)
    Rx->>Rx: Estimate Channel State (CSI)
    Rx->>Rx: Compute Anti-Aliasing Filter Coefficients
    Rx->>Rx: Generate Hash(CSI, Coefficients)
    Rx->>BC: Commit Hash to Blockchain
    BC->>BC: Validate & Record Transaction
    Rx->>Rx: Apply Anti-Aliasing & Decode Data
    alt Malicious Activity Detected
        BC->>Rx: Alert: CSI/Coeff. Mismatch
        Rx->>Rx: Revert to Last Verified State
    end

5. The "Inverse" or Failure Mode

This axis describes versions of the invention designed to fail safely or operate in limited-functionality/low-power modes.

Derivative 5.1: Low-Power, Single-Channel Fallback with Deactivated Gap-Filling

• Enabling Description: The wireless device (Claims 12, 20) incorporates a low-power mode where it deactivates the second radio chain and ceases transmission/reception of gap-filling subcarriers. When battery power falls below a threshold, or signal quality on one channel drops below a configurable error rate, the system automatically transitions from wideband dual-channel operation to a robust single-channel legacy mode (e.g., 802.11a/g). In this mode, only the primary channel's OFDM signal is processed, and the adaptive anti-aliasing circuit may be partially or entirely bypassed or reconfigured for a simpler, lower-power filtering scheme, as adjacent channel interference is no longer a concern. This conserves energy and ensures a basic, reliable communication link when full performance is not sustainable or required.

stateDiagram
    state "High-Performance Wideband Mode" as HPWM
    state "Low-Power Single-Channel Mode" as LPSCM

    HPWM --> LPSCM: Battery < Threshold / Channel Degradation
    LPSCM --> HPWM: Battery > Threshold / Channel Recovery

    HPWM: Dual-Channel Tx/Rx
    HPWM: Gap-Filling Active
    HPWM: Full Adaptive Anti-Aliasing

    LPSCM: Single-Channel Tx/Rx
    LPSCM: Gap-Filling Deactivated
    LPSCM: Basic Filtering / Reduced Anti-Aliasing

Derivative 5.2: Diagnostic Aliasing Characterization Mode

• Enabling Description: The wireless device (Claims 12, 20) includes a specialized diagnostic mode where the adaptive anti-aliasing function (Claims 19, 20) is intentionally disabled or selectively degraded. This allows the system to capture and analyze the raw, unmitigated aliasing effects due to adjacent channel waveforms (e.g., FIG. 36, 37, 38). By transmitting known test patterns across the two channels (Claim 1, 12) with and without gap-filling, the receiver can precisely characterize the spectral leakage and inter-subcarrier interference before anti-aliasing is applied. This mode is invaluable for system calibration, debugging, and for developing more sophisticated adaptive anti-aliasing algorithms by providing ground-truth data on interference profiles without active compensation.

flowchart TD
    A[Wideband OFDM Rx] --> B{Signal Separator}
    B -- Ch1, Ch2 Raw --> C{Aliasing Characterization Module}
    C -- Disable/Degrade --> D[Adaptive Anti-Aliasing]
    C --> E[Raw Aliasing Data Capture]
    E --> F[Diagnostic Analysis & Report]
    D --> G[Decoded Data (Optional)]

Derivative 5.3: Adaptive Fault Tolerance through Selective Subcarrier Disablement

• Enabling Description: In the event of detected hardware failure (e.g., one radio chain partially failing, or an ADC exhibiting excessive noise) or persistent, unmitigable interference on specific subcarriers, the transmitting device (Claims 1, 12) can dynamically disable or 'null' problematic subcarriers, particularly those used for gap-filling. The system communicates these disabled subcarrier indices to the receiver (Claims 19, 20) via a robust control channel. The receiver's adaptive anti-aliasing and decoding logic then adapts to ignore or treat these nulled subcarriers as empty, preventing them from corrupting valid data. This ensures graceful degradation of the link rather than catastrophic failure, maintaining a reduced but functional data rate. This also applies to the adaptive anti-aliasing, where certain filter taps or weights associated with compromised subcarriers can be de-emphasized or zeroed out.

classDiagram
    class MultiChannelTransmitter {
        +OFDMSignalGenerator[]
        +SubcarrierAllocator
        +FaultDetector
        +ControlChannel
        +Transmit(OFDMSignal[])
    }
    class MultiChannelReceiver {
        +SignalSeparator
        +AdaptiveAntiAliaser
        +Decoder
        +ControlChannel
        +Receive(WidebandOFDM)
    }
    class FaultDetector {
        +DetectHardwareFailure()
        +IdentifyProblematicSubcarriers()
    }
    class SubcarrierAllocator {
        +Allocate(data, gap_fill_strategy)
        +DisableSubcarriers(indices)
    }
    class AdaptiveAntiAliaser {
        +Apply(received_signals)
        +AdaptToDisabledSubcarriers(indices)
    }
    MultiChannelTransmitter "1" -- "1" FaultDetector : <<uses>>
    MultiChannelTransmitter "1" -- "1" SubcarrierAllocator : <<uses>>
    MultiChannelTransmitter "1" -- "1" ControlChannel : <<uses>>
    MultiChannelReceiver "1" -- "1" SignalSeparator : <<uses>>
    MultiChannelReceiver "1" -- "1" AdaptiveAntiAliaser : <<uses>>
    MultiChannelReceiver "1" -- "1" ControlChannel : <<uses>>

---

Combination Prior Art Scenarios with Open-Source Standards

Here are three scenarios combining the principles of US8027326 with existing open-source standards to establish prior art for future incremental improvements.

1. US8027326 + Openwifi (Open-Source 802.11 Full Stack Implementation)

• Scenario: An implementation of the multi-channel, gap-filled OFDM transmission and adaptive anti-aliasing reception described in US8027326 using the Openwifi framework. Openwifi is an open-source software-defined radio (SDR) project providing a full-stack 802.11 implementation on platforms like Ettus USRPs.
• Combination: A developer leverages Openwifi's existing 802.11a/g PHY and MAC layers. They modify the OFDM signal generation module (e.g., the IFFT block in the transmitter, FIG. 16) to concatenate two 20 MHz 802.11a-like channels and insert additional subcarriers into the frequency gap using custom DSP functions within the SDR. On the receive side (e.g., FIG. 33), two parallel Openwifi receiver instances are configured to process the adjacent channels. The adaptive anti-aliasing is implemented as a custom module in the digital signal processing (DSP) pipeline (e.g., before the FFT, or a frequency-domain equalizer based on FIG. 54 or 55), exchanging cancellation coefficients between the two parallel receive paths to mitigate aliasing. The Openwifi MAC layer is extended to signal the use of bonded, gap-filled channels and to exchange anti-aliasing training sequences.
• Result: A fully functional, open-source demonstration of high data rate multi-channel WLAN with gap-filling and adaptive anti-aliasing, available for public scrutiny and implementation.

2. US8027326 + GNU Radio (Software Defined Radio Toolkit)

• Scenario: Utilizing GNU Radio, a free & open-source software development toolkit that provides signal processing blocks to implement software radios, to implement and simulate the multi-channel, gap-filled OFDM system with adaptive anti-aliasing.
• Combination: A GNU Radio flowgraph is constructed. On the transmit path, two independent OFDM signal generators (based on existing 802.11-like modules in GNU Radio) are used, with their outputs up-converted and spectrally combined, and a custom 'gap-filling' block inserting additional subcarriers into the intermediate frequency range. This combined signal is then transmitted via an SDR hardware (e.g., HackRF, BladeRF). On the receive path, a wideband receiver samples the RF spectrum, and the digitized signal is fed into two parallel GNU Radio signal processing chains, each performing channel decomposition (e.g., down-conversion, filtering with a customizable FIR filter). An adaptive filter block (e.g., using GNU Radio's built-in adaptive algorithms or a custom Python block implementing LMS or RLS) is connected between the two chains to perform real-time anti-aliasing, subtracting interference components based on estimated cross-channel leakage.
• Result: A reproducible, open-source, software-defined implementation and simulation environment for the core inventive concepts, demonstrating their feasibility and operability using off-the-shelf SDR hardware.

3. US8027326 + O-RAN Alliance Specifications (Open Radio Access Network)

• Scenario: Integration of the multi-channel, gap-filled OFDM approach with adaptive anti-aliasing within an Open Radio Access Network (O-RAN) architecture, specifically within the O-RU (O-RAN Radio Unit) and O-DU (O-RAN Distributed Unit).
• Combination: The O-RU, acting as the physical layer front-end (similar to the radio chains in Claims 12, 20), implements the parallel transmit and receive functionality for two adjacent channels. The digital baseband processing (OFDM signal generation, subcarrier mapping, DAC/ADC interfacing) for both the gap-filling subcarriers (Tx) and the adaptive anti-aliasing (Rx) is offloaded to the O-DU. The O-DU (acting as the processor in Claims 12, 20) orchestrates the channel bonding and anti-aliasing algorithms, dynamically adjusting parameters based on network-wide traffic and interference conditions reported via O-RAN's open interfaces (e.g., E2 interface to an intelligent controller, near-RT RIC). The O-RU implements the necessary filtering (e.g., 6th order LPFs as in FIG. 11) and provides the raw I/Q samples to the O-DU for centralized, adaptive anti-aliasing processing.
• Result: An open, disaggregated radio access network architecture that incorporates the high data rate multi-channel techniques, leveraging open interfaces and centralized intelligence to manage spectrum, interference, and resource allocation.