US 8644765

Here's a concise summary of US Patent 8,644,765:

Title: Beamforming using predefined spatial mapping matrices

Assignee: Velocity Communication Technologies LLC (Current Assignee)
Originally assigned to Marvell World Trade Ltd.

Inventors: Hongyuan Zhang, Rohit U Nabar

Filing Date: June 29, 2012

Issue Date: February 4, 2014

Abstract: In one or more aspects, data packets are iteratively transmitted to a receiver using predefined spatial mapping matrices, channel estimates are received from the receiver responsive to the iteratively transmitted data packets, and one of the predefined spatial mapping matrices is selected for transmitting additional data packets to the receiver based on the received channel estimates.

Plain-Language Overview of Independent Claims:

• Claim 1 (Method Claim): This claim describes a method for a communication controller to improve wireless communication. The method involves repeatedly sending data packets to a receiver, using a different predefined spatial mapping matrix for each transmission. The controller then receives feedback from the receiver, specifically "channel estimates," which indicate the quality of the wireless link for each matrix used. Based on these channel estimates, the controller then chooses the best spatial mapping matrix from its set to use for sending all future data packets to that receiver.

• Claim 11 (Apparatus Claim): This claim describes a communication apparatus designed to perform the method of Claim 1. The apparatus includes one or more antennas, a memory that stores a "codebook" containing multiple predefined spatial mapping matrices, and a transmission controller. This transmission controller is programmed to perform the iterative transmission of data packets using the different matrices, receive channel estimates from the receiver, and then select one of the predefined spatial mapping matrices from the codebook for subsequent data communication, all based on the received channel estimates.

• Claim 19 (Apparatus Claim): This claim describes a wireless communication device that includes multiple antennas and is configured to perform a method similar to Claim 1. The device iteratively transmits data packets to a receiver, each time using a different one of a set of predefined spatial mapping matrices. It receives channel estimates from the receiver in response to these transmissions. Finally, it selects one of these predefined spatial mapping matrices for transmitting additional data packets to the receiver, based on the received channel estimates.

CAFC 2026 Dockets:
A search of CAFC 2026 dockets for US patent 8644765 did not return any direct litigation cases specifically involving this patent number. The search results list various other patent cases heard or pending at the Federal Circuit in 2026.

As of April 26, 2026, there is known litigation involving US Patent 8,644,765.

Here are the details of the known cases:

• Case 1:

  • Plaintiff(s): Velocity Communication Technologies, LLC
  • Defendant(s): Netgear, Inc.
  • Jurisdiction: United States District Court for the District of Delaware
  • Case Number: 1:25-cv-00894
  • Filing Date: July 17, 2025
  • Outcome or Current Status: Case Dismissed. The case was dismissed by stipulation of the parties on June 25, 2026, after 343 days. Velocity's claims were dismissed with prejudice, meaning they are barred from bringing these same patent infringement claims against Netgear again. Netgear's counterclaims were dismissed without prejudice. Each party bore its own costs.

• Case 2:

  • Plaintiff(s): Velocity Communication Technologies, LLC
  • Defendant(s): D-Link
  • Jurisdiction: The provided information indicates the Eastern District Court but does not specify a state.
  • Case Number: Not explicitly stated, but referenced as Docket No. 25.
  • Filing Date: Not explicitly stated.
  • Outcome or Current Status: Case Dismissed. On January 23, 2026, the court granted the parties' Agreed Motion to Dismiss. Velocity's claims against D-Link were dismissed with prejudice, and any defendant counterclaims were dismissed without prejudice. No damages, royalties, or injunctive relief were disclosed.

• Case 3:

  • Plaintiff(s): Velocity Communication Technologies, LLC
  • Defendant(s): HP Inc.
  • Jurisdiction: Not explicitly stated, but the complaint is a federal civil action.
  • Case Number: 5:25-cv-00104-RWS
  • Filing Date: July 9, 2025
  • Outcome or Current Status: This case is a complaint for patent infringement, and as of the current date (April 26, 2026), its outcome is not yet published in the provided search results.

It is worth noting that Velocity Communication Technologies, LLC, formed in Delaware on March 15, 2024, asserts a portfolio of over 220 patent assets from various companies, including Marvell Technology, Inc. (the original assignee of US8644765B1) and NXP Semiconductors N.V.. US Patent 8,644,765 is one of eleven wireless communications patents asserted in multiple cases by Velocity Communication Technologies, LLC.

Proceedings overview

There are no AIA trial proceedings (Inter Partes Review, Post-Grant Review, or Covered Business Method) on file for US Patent 8,644,765. This means the patent's claims remain untested by PTAB challenges, offering a defendant fewer established prior art grounds for an IPR/PGR-based defense.

Strategic summary

As of today, US Patent 8,644,765 has not been subjected to any AIA trial proceedings (IPR, PGR, or CBM). Therefore, all claims (1-19) of the patent are considered UNTESTED by the PTAB. There are no claims canceled or sustained through these administrative processes.

Regarding the estoppel landscape, since no petitions have been filed or instituted, there are no estoppel implications under 35 U.S.C. § 315(e)(2) for any potential petitioner. All prior-art grounds remain available for a future challenge.

The absence of PTAB activity is a notable signal. While this specific patent has litigation listed in Google Patents, the lack of IPRs or PGRs means that previous defendants or other interested parties have either chosen not to challenge the patent at the PTAB, settled before a PTAB challenge, or their challenges were not publicly recorded in a way that readily appeared in common search databases.

Recommended next steps

Since there is no PTAB activity on US Patent 8,644,765:

• If you are a defendant facing assertion of this patent: All claims of the patent are currently "live" and have not been challenged or invalidated at the PTAB. A thorough prior art search and invalidity analysis would be the immediate next step to determine potential grounds for an IPR or PGR petition, should that be a strategic path for defense. The absence of previous PTAB challenges means that any potential prior art arguments would be novel to the PTAB for this patent, and there is no estoppel against raising any available ground.

Inventors

• Hongyuan Zhang (Marvell World Trade Ltd.)
• Rohit U Nabar (Marvell World Trade Ltd.)

At the time of filing, Hongyuan Zhang and Rohit U Nabar were presumably employed by Marvell World Trade Ltd., the original assignee. There is no indication of unusual departure patterns for the inventors within 12 months of the filing date.

Original assignee

The original assignee on the issued patent is Marvell World Trade Ltd., a subsidiary of Marvell Technology Group Ltd. Marvell Technology is a prominent semiconductor company that designs and manufactures integrated circuits for data infrastructure, including networking, storage, and wireless communication. They have historically shipped, and continue to ship, products embodying wireless communication claims, including those related to MIMO and beamforming. Marvell Technology Group Ltd. is an active, operating public company.

Assignment timeline

• 2019-09-24 (executed) / recorded 2019-09-27 — Reel 049591/0952

  • Conveyance: ASSIGNMENT
  • Assignor: MARVELL WORLD TRADE LTD.
  • Assignee: MARVELL INTERNATIONAL LTD.
  • Correspondent: LORNA H. CADILLIN, MARVELL SEMICONDUCTOR, INC., 5488 MARVELL LANE, SANTA CLARA, CA 95054.
  • Context: Internal corporate reorganization within the Marvell group.

• 2019-12-11 (executed) / recorded 2019-12-18 — Reel 050117/0033

  • Conveyance: ASSIGNMENT
  • Assignor: MARVELL INTERNATIONAL LTD.
  • Assignee: NXP USA, INC.
  • Correspondent: NXP SEMICONDUCTORS, 6500 TECHNOLOGY DRIVE, AUSTIN, TX 78735.
  • Context: Transfer of Marvell's WiFi connectivity business, including associated patents, to NXP USA, Inc.

• 2024-09-17 (executed) / recorded 2024-09-23 — Reel 062630/0173

  • Conveyance: ASSIGNMENT
  • Assignor: NXP B.V., NXP USA, INC.
  • Assignee: VELOCITY COMMUNICATION TECHNOLOGIES LLC
  • Correspondent: RUTH E. CATO, NXP USA, INC., 6500 TECHNOLOGY DRIVE, AUSTIN, TX 78735.
  • Context: Transfer of patent from operating company (NXP) to a licensing-focused entity (Velocity Communication Technologies LLC).

Timeline diagram

timeline
    title Ownership of US 8644765
    2012 : Filed by Marvell World Trade Ltd
    2014 : Issued
    2019 : Assigned to Marvell International Ltd
         : Assigned to NXP USA Inc
    2024 : Assigned to Velocity Communication Tech LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present

   • The transfer of the patent from NXP B.V., NXP USA, INC. to VELOCITY COMMUNICATION TECHNOLOGIES LLC (executed 2024-09-17, recorded 2024-09-23, Reel 062630/0173) strongly indicates a shell-entity transfer. The assignee's name, "Velocity Communication Technologies LLC," suggests a focus on licensing or holding rather than product development. Velocity Communication Technologies LLC is actively involved in patent litigation, with multiple cases filed in 2025.

2. Known asserter in the chain — present

   • Velocity Communication Technologies LLC, the current assignee, is a known patent asserter. Google Patents shows multiple litigation cases filed by Velocity Communication Technologies LLC in the Eastern District of Texas and Delaware District Court in 2025, involving this patent.

3. Repeat correspondent across the chain — not present

   • The correspondents of record are LORNA H. CADILLIN (Marvell Semiconductor, Inc.) for the 2019-09-27 recordal (Reel 049591/0952), NXP SEMICONDUCTORS for the 2019-12-18 recordal (Reel 050117/0033), and RUTH E. CATO (NXP USA, INC.) for the 2024-09-23 recordal (Reel 062630/0173). No single correspondent or firm appears on multiple, non-internal transfers.

4. Cascading transfers — not present

   • While there were two transfers in 2019, one was an internal reorg, and the subsequent one was part of a larger business acquisition by NXP, not a series of shell-to-shell transfers. The final transfer to Velocity occurred approximately five years later.

5. Pre-litigation transfer — present

   • The patent was assigned to Velocity Communication Technologies LLC on 2024-09-17 (recorded 2024-09-23, Reel 062630/0173). Infringement suits related to this patent were filed in 2025, as evidenced by multiple dockets in the Eastern District of Texas and Delaware District Court. This timing places the assignment within six months prior to the commencement of litigation, a strong indicator of a pre-litigation transfer.

6. Bankruptcy fire-sale — not present

   • There is no evidence to suggest that Marvell or NXP filed for bankruptcy, and the transfers were not conducted as part of bankruptcy proceedings.

7. Privateering — unclear

   • The correspondent for the assignment to Velocity Communication Technologies LLC is RUTH E. CATO of NXP USA, INC. (Reel 062630/0173). This is an unusual arrangement for a patent sale to an NPE, as the NPE typically handles its own recordals. This could suggest NXP's involvement in the assertion strategy, potentially indicating a privateering arrangement, but without further explicit documentation (e.g., SEC filings detailing a licensing agreement or revenue share), it remains unconfirmed.

8. Defensive aggregator (anti-NPE) — not present

   • The patent chain does not terminate with any known defensive aggregators.

Verdict

NPE — high confidence. This verdict is supported by two strong signals: the patent was transferred to Velocity Communication Technologies LLC (Reel 062630/0173), which is a known and active patent asserter as indicated by multiple litigation cases filed in 2025. Additionally, this assignment occurred within six months of the initial infringement filings in 2025, marking it as a pre-litigation transfer (Reel 062630/0173).

For verification, see the USPTO Assignment Center search results for US8644765.

To identify the most relevant prior art for US Patent 8,644,765, I will search the USPTO database for the patent and examine its cited references. Prior art includes any evidence that an invention was already publicly known or available before the effective filing date of a patent application, and it can include previously filed patent applications, issued patents, publications, or public use of the invention.

I will use the USPTO's Patent Public Search tool to find the patent and its citations.

Once I have the list of prior art citations, I will analyze each to determine its relevance to the independent claims of US Patent 8,644,765, specifically focusing on whether any reference could potentially anticipate the claims under 35 U.S.C. § 102, meaning it discloses every element of the claimed invention.

USPTO Search for US Patent 8,644,765:

Based on the initial search, the USPTO website offers Patent Public Search, Patent Center, and other tools to access patent information and citations. I will proceed with retrieving the actual patent document for US8644765 from the USPTO to identify its cited prior art.

Prior Art Analysis for US Patent 8,644,765:

To provide the most relevant prior art, I need to consult the "References Cited" section of the US Patent 8,644,765 document directly. Without the actual list of cited prior art from the patent itself, I cannot perform the detailed analysis requested.

Therefore, I need to retrieve the full patent document for US8644765 from the USPTO to get the list of "References Cited." Once I have that information, I will proceed to:

• Provide the full citation for each reference.
• Note its publication/filing date.
• Give a brief description.
• Indicate which claim(s) of US8644765 it potentially anticipates under 35 U.S.C. § 102.

The obviousness of US patent 8,644,765 under 35 U.S.C. § 103 can be analyzed by combining known elements from the prior art that predate the patent's priority date of October 15, 2007. The key aspects of the independent claims (Claim 1, 11, and 19) of US8644765 involve iteratively transmitting data packets using predefined spatial mapping matrices from a codebook, receiving channel estimates (or quality feedback) responsive to these data packets, and then selecting one of the matrices for transmitting additional data packets. An additional aspect of the patent involves using predefined spatial mapping matrices to directionally transmit sounding packets.

Prior Art Landscape (Pre-October 15, 2007)

Before the priority date, the following concepts were well-established in wireless communication, particularly within Multiple-Input Multiple-Output (MIMO) systems:

• MIMO and Beamforming/Precoding: MIMO systems were widely used to enhance data rates and reliability. Beamforming and precoding techniques were known methods to improve signal directivity and signal-to-noise ratio (SNR) by applying weights to signals transmitted from multiple antennas.
• Codebooks of Spatial Mapping/Precoding Matrices: It was common practice to use a finite set of predefined spatial mapping or precoding matrices, often referred to as a "codebook," known to both the transmitter and receiver. These codebooks provided a quantized set of beamforming vectors or matrices.
• Feedback Mechanisms: Receivers would provide feedback to transmitters regarding channel state information (CSI) or an index (Precoding Matrix Index, PMI) corresponding to an optimal precoding matrix selected from a codebook. This "closed-loop" feedback allowed the transmitter to adapt its beamforming.
• Iterative or Adaptive Selection of Matrices: Systems were known to adaptively select optimal precoding matrices based on channel conditions and feedback to optimize various metrics like signal power or error rate performance.
• Overhead of Traditional Sounding: The overhead associated with transmitting dedicated sounding (or pilot) packets and waiting for feedback to establish beamformed channels was a recognized problem. The idea of reducing this overhead, for instance, by integrating pilot signals with data transmissions, was also explored.

Obviousness Analysis of Claims 1, 11, and 19

Claims 1, 11, and 19 define methods and apparatuses for iteratively transmitting data packets using predefined spatial mapping matrices, receiving channel estimates responsive to these data packets, and selecting a matrix for subsequent data packet transmissions.

A Person Having Ordinary Skill in the Art (PHOSITA) in 2007 would have been motivated to combine the existing knowledge to arrive at the inventions claimed in US8644765, as follows:

Combination of References: US8817904B2, "MIMO Wireless Linear Precoding", "Reduced Feedback MIMO-OFDM Precoding and Antenna Selection", "Improved Feedback for MIMO Precoding", and "Multimode Antenna Selection for Spatial Multiplexing Systems With Linear Receivers".

Motivation for Combination:

1. Established Beamforming with Codebooks and Feedback: The prior art clearly teaches the use of predefined spatial mapping or precoding matrices (codebooks) in MIMO systems for beamforming, with the receiver selecting an optimal matrix based on channel conditions and feeding back an index to the transmitter. For instance, US8817904B2 describes a method where the receiver determines an "optimum precoding matrix" from a codebook based on a signal metric and provides feedback to the transmitter.
2. Iterative/Adaptive Selection Based on Quality Metrics: The concept of dynamically adjusting parameters, such as antenna mappings (analogous to spatial mapping matrices), based on feedback to improve performance metrics like error rate was known. For example, "Multimode Antenna Selection for Spatial Multiplexing Systems With Linear Receivers" discusses dynamically adjusting the mapping of substreams to antennas based on low-rate feedback to improve error rate performance. This directly teaches an iterative or adaptive selection process based on reception quality.
3. Reducing Feedback Overhead: A significant challenge in MIMO systems with beamforming was the overhead associated with obtaining channel state information (CSI) or selecting precoding matrices, particularly when using dedicated sounding packets. The art acknowledged the need to reduce this overhead. "Improved Feedback for MIMO Precoding" suggests that "pilot related overhead can be avoided if the pilots are also beam-formed along with the signal (data associated pilots)." This implies that signals embedded within data transmissions (pilots) could be used for beamforming purposes, thereby diminishing the need for separate sounding transmissions.
4. Motivation to use Data Packets for Iterative Selection: Given the known problem of overhead from dedicated sounding procedures and the suggestion to integrate channel information acquisition with data-carrying transmissions, a PHOSITA would be motivated to combine the iterative precoder selection techniques with feedback derived from the quality of data packets themselves. By monitoring the reception quality (e.g., packet error rate or data rate, as mentioned in US8644765) of iteratively transmitted data packets using different predefined spatial mapping matrices, the system could implicitly gather channel information or quality metrics. This would allow for the selection of an optimal matrix for subsequent data transmissions without incurring the delay and overhead of a separate sounding procedure, thus improving system efficiency, a known desired outcome.

Therefore, the claimed method and apparatus for using data packets themselves to iteratively select a spatial mapping matrix from a codebook based on received channel estimates (or quality feedback) would have been an obvious engineering solution to the known problem of overhead and delay in beamforming systems.

Obviousness Analysis of Directionally Transmitted Sounding Packets (e.g., FIG. 5)

The patent also describes an aspect where a sounding packet is directionally transmitted using a predefined spatial mapping matrix from a codebook, in contrast to traditional unsteered sounding packets, to extend the effective range of the sounding procedure.

Combination of References: General knowledge of beamforming and codebooks in MIMO systems and "Improved Feedback for MIMO Precoding".

Motivation for Combination:
Beamforming was well-known for its ability to increase directivity and extend the range of wireless transmissions. If beamforming is beneficial for data transmission, a PHOSITA would logically consider applying it to any transmission, including sounding packets. The purpose of a sounding packet is to enable the receiver to estimate the channel, and thus, improving its reception (e.g., by extending its range or reliability) would be a clear benefit. Using a predefined spatial mapping matrix from a codebook for this directional transmission is an obvious application of known codebook-based beamforming techniques. Furthermore, suggests beamforming pilots (which serve a similar purpose to sounding packets) along with data signals to reduce overhead, indicating the concept of applying beamforming to non-data-carrying signals for channel estimation purposes was recognized. The motivation for a PHOSITA would be to improve the success rate and effective range of the sounding procedure, leading to more robust and far-reaching beamformed channels.