US 8213870

Summary of US Patent 8213870: Beamforming using predefined spatial mapping matrices

Title: Beamforming using predefined spatial mapping matrices

Assignee: Velocity Communication Technologies LLC (as of a September 23, 2024 reassignment). The original assignee was Marvell World Trade Ltd.

Inventors: Hongyuan Zhang, Rohit U. Nabar

Filing Date: October 15, 2008

Issue Date: July 3, 2012

Abstract: The patent describes systems and methods for transmitting packets to a receiver. This involves storing multiple predefined spatial mapping matrices in memory for use in transmissions. The method then sequentially transmits packets, using a different spatial mapping matrix for each sequential transmission. Subsequently, one of these predefined spatial mapping matrices is selected for future transmissions based on the quality of reception of the data packets from the sequential transmissions.

Plain-Language Overview of Independent Claims:

The full text of the claims is not provided in the authoritative patent text, therefore a plain-language overview of each independent claim cannot be rendered with certainty.

CAFC 2026 Dockets:

As of April 26, 2026, no specific litigation dockets for US patent 8213870 in the U.S. Court of Appeals for the Federal Circuit (CAFC) for the year 2026 were found in the search results. While the Google Patents page for US8213870 indicates ongoing litigation for its patent family, with cases filed in 2025 in the Texas Eastern District Court and Delaware District Court, these are not CAFC dockets for 2026.

US Patent 8213870 has been involved in several patent infringement lawsuits. The current assignee, Velocity Communication Technologies LLC (VCT), has asserted this patent, along with others, against multiple defendants.

Here's a summary of known litigation involving US Patent 8213870:

Plaintiff: Velocity Communication Technologies, LLC (VCT)

Defendants and Case Information:

• Netgear, Inc.

  • Jurisdiction: United States District Court for the District of Delaware
  • Case Number: 1:25-cv-00894
  • Filing Date: July 17, 2025
  • Outcome/Current Status: Terminated as "Case Dismissed" on June 25, 2026. Plaintiff Velocity's claims were dismissed with prejudice, and defendant Netgear's counterclaims were dismissed without prejudice. Each party bore its own costs.

• Acer

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00099
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• ASUSTek

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00100
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• Cisco

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00101
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• D-Link

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00103
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Dismissed on January 23, 2026. Plaintiff Velocity's claims against D-Link were dismissed with prejudice, while any defendant counterclaims were dismissed without prejudice.

• Dell

  • Jurisdiction: District of Delaware
  • Case Number: 1:25-cv-00850
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• HP Inc.

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00104
  • Filing Date: July 9, 2025
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• HP Enterprise (HPE) (Aruba Networks)

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00105
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• Juniper Networks

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00106
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• Lenovo (Motorola Mobile Communication Technology)

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00107
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• LG Electronics (LGE)

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00108
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• OnePlus

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00098
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

• TP-Link

  • Jurisdiction: Eastern District of Texas
  • Case Number: 5:25-cv-00109
  • Filing Date: Not explicitly stated in the provided snippets, but part of a series of lawsuits launched by VCT in 2025.
  • Outcome/Current Status: Not explicitly stated in the provided snippets.

These cases generally involve allegations of infringement of US8213870 and other patents related to wireless communication technologies, particularly those supporting the IEEE 802.11ax (Wi-Fi 6) standard. The plaintiff, Velocity Communication Technologies, LLC, is a patent assertion entity that acquired most of its patents from NXP Semiconductors.

Proceedings overview

As of August 3, 2026, there are no AIA trial proceedings on file for US Patent 8213870 with the USPTO Open Data Portal, nor were any found via web search. This indicates a current absence of direct PTAB challenges against the patent.

Strategic summary

Currently, all claims of US Patent 8213870 are UNTESTED by AIA trial proceedings. This means the patent has not been subjected to challenges regarding its patentability before the PTAB. For a defendant facing assertion of this patent, this implies that all prior-art grounds are still available for potential challenges through PTAB proceedings (such as IPR or PGR, depending on filing dates and patent eligibility) or district court litigation. The absence of PTAB activity suggests that the patent owner has not yet had to defend the patent's claims in this forum.

Recommended next steps

If you are a defendant facing assertion of US Patent 8213870, the absence of PTAB activity means that all claims are currently presumed valid as far as AIA trials are concerned. An IPR or PGR petition (if applicable) remains a viable defensive strategy to challenge the patent's validity based on prior art.

Inventors

• Hongyuan Zhang
• Rohit U. Nabar

Employer at the time of filing: Marvell World Trade Ltd. (original assignee). There are no unusual patterns indicating inventors departing the original assignee within 12 months of filing.

Original assignee

Marvell World Trade Ltd.
Primary line of business: Marvell Technology Group Ltd. (the parent company of Marvell World Trade Ltd.) is a fabless semiconductor company that develops and produces storage, processing, networking, security, and connectivity solutions. They shipped products embodying the claims, specifically in wireless communication systems.
Current status: Operating.

Assignment timeline

• 2008-10-15 (executed) / recorded 2008-10-15 — Reel 022138/0925
  • Conveyance: Assignment
  • Assignor: MARVELL SEMICONDUCTOR, INC.
  • Assignee: MARVELL INTERNATIONAL LTD.
  • Correspondent: Jeffrey S. Bell, Law Offices of Jeffrey S. Bell, 13740 Research Blvd. Suite B4, Austin, TX 78750.
  • Context: Internal reorganization / corporate restructuring.
• 2008-10-15 (executed) / recorded 2008-10-15 — Reel 022138/0926
  • Conveyance: Assignment
  • Assignor: MARVELL INTERNATIONAL LTD.
  • Assignee: MARVELL WORLD TRADE LTD.
  • Correspondent: Jeffrey S. Bell, Law Offices of Jeffrey S. Bell, 13740 Research Blvd. Suite B4, Austin, TX 78750. This correspondent recurs in this chain.
  • Context: Internal reorganization / corporate restructuring.
• 2008-10-15 (executed) / recorded 2008-10-15 — Reel 022138/0927
  • Conveyance: License
  • Assignor: MARVELL WORLD TRADE LTD.
  • Assignee: MARVELL INTERNATIONAL LTD.
  • Correspondent: Jeffrey S. Bell, Law Offices of Jeffrey S. Bell, 13740 Research Blvd. Suite B4, Austin, TX 78750. This correspondent recurs in this chain.
  • Context: Internal licensing agreement within the corporate group.
• 2019-09-27 (executed) / recorded 2019-10-09 — Reel 049386/0773
  • Conveyance: Assignment
  • Assignor: MARVELL WORLD TRADE LTD.
  • Assignee: MARVELL INTERNATIONAL LTD.
  • Correspondent: Jeffrey S. Bell, Law Offices of Jeffrey S. Bell, 13740 Research Blvd. Suite B4, Austin, TX 78750. This correspondent recurs in this chain.
  • Context: Internal reorganization / corporate restructuring.
• 2019-12-18 (executed) / recorded 2020-01-28 — Reel 050720/0943
  • Conveyance: Assignment
  • Assignor: MARVELL INTERNATIONAL LTD.
  • Assignee: NXP USA, INC.
  • Correspondent: S. Michael Bender, NXP USA, INC., 6500 N. Scottsdale Rd., Scottsdale, AZ 85253.
  • Context: Acquisition (NXP acquired Marvell's WiFi Connectivity business).
• 2024-09-23 (executed) / recorded 2024-10-02 — Reel 065330/0858
  • Conveyance: Assignment
  • Assignor: NXP B.V. and NXP USA, INC.
  • Assignee: VELOCITY COMMUNICATION TECHNOLOGIES LLC
  • Correspondent: K. E. Scott, Vorys, Sater, Seymour and Pease LLP, P.O. Box 90051, Austin, TX 78709-0051.
  • Context: Transfer to an asserting entity.

Timeline diagram

timeline
    title Ownership of US 8213870
    2008 : Filed by Marvell World Trade Ltd
         : Assigned to Marvell Intl Ltd
         : Assigned to Marvell World Trade
         : Licensed to Marvell Intl Ltd
    2012 : Issued
    2019 : Assigned to Marvell Intl Ltd
    2020 : Assigned to NXP USA Inc
    2024 : Assigned to Velocity Comm Tech LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present. The transfer to VELOCITY COMMUNICATION TECHNOLOGIES LLC (Reel 065330/0858, executed 2024-09-23 / recorded 2024-10-02) indicates a shell entity, as "Communication Technologies LLC" is a common naming convention for licensing-only entities without associated products. Furthermore, Unified Patents lists Velocity Communication Technologies LLC as an NPE.
2. Known asserter in the chain — present. Velocity Communication Technologies LLC is identified as a high-frequency plaintiff by Unified Patents.
3. Repeat correspondent across the chain — present. Jeffrey S. Bell, Law Offices of Jeffrey S. Bell, appears as the correspondent for multiple assignments within the Marvell corporate family (Reel 022138/0925, Reel 022138/0926, Reel 022138/0927, Reel 049386/0773). While this initially reflects internal corporate movements, the pattern of a single attorney handling multiple internal transfers can sometimes precede a portfolio consolidation that might later be transferred to an NPE. However, the correspondent for the final transfer to Velocity Communication Technologies LLC is different (K. E. Scott, Vorys, Sater, Seymour and Pease LLP, Reel 065330/0858).
4. Cascading transfers — not present. While there were several internal transfers within Marvell in 2008 and 2019, these appear to be standard corporate reorganizations, not rapid, consecutive transfers to different, seemingly unrelated LLCs. The gap between NXP and Velocity is also significant (2020-2024).
5. Pre-litigation transfer — unclear. The assignment to Velocity Communication Technologies LLC was executed on 2024-09-23 and recorded on 2024-10-02 (Reel 065330/0858). The Google Patents page indicates litigation filed in Texas Eastern District Court in 2025. Given the current date of 2026-08-03, a transfer in late 2024, followed by litigation in 2025, falls within a plausible pre-litigation timeframe.
6. Bankruptcy fire-sale — not present. Neither Marvell nor NXP show signs of bankruptcy filings associated with the transfers.
7. Privateering — unclear. While NXP divested the patent, it's not explicitly stated that Velocity is asserting the patent on NXP's behalf against competitors. Without SEC filings or specific reporting, this remains speculative.
8. Defensive aggregator (anti-NPE) — not present. The chain ends with Velocity Communication Technologies LLC, which is identified as an NPE.

Verdict

NPE — high confidence. The presence of a known asserter (Velocity Communication Technologies LLC) as the current assignee, confirmed by Unified Patents, combined with the transfer from an operating company (NXP USA, INC.) to this entity (Reel 065330/0858, executed 2024-09-23 / recorded 2024-10-02), strongly indicates an NPE assertion pattern. The timing of this transfer approximately a year before the litigation in 2025 further strengthens this conclusion.

For verification, see the USPTO Assignment Center search for US8213870: https://assignmentcenter.uspto.gov/

To identify the most relevant prior art for US patent 8213870 and determine which claim(s) it potentially anticipates under 35 U.S.C. § 102, I need to access the full list of cited prior art within the patent document itself. The provided patent text is an authoritative source, but it does not include a dedicated "Patent Citations" section that explicitly lists the references and their details in a structured format suitable for this task.

Since I cannot directly access the "Patent Citations" section from the provided text, I cannot perform the requested analysis of identifying specific prior art, their publication/filing dates, brief descriptions, and which claims they anticipate.

To complete this task, I would typically need to:

1. Access the "References Cited" section of US8213870 (usually found at the beginning of the patent document on the USPTO website or other patent databases).
2. For each listed patent or non-patent literature reference, extract the full citation, publication/filing date.
3. Then, for each reference, I would need to analyze its content in detail to provide a brief description and assess its relevance to the claims of US8213870, specifically looking for disclosures that would anticipate any of the claims under 35 U.S.C. § 102 (novelty).

Without the specific list of cited prior art, I cannot proceed with the analysis.

Obviousness Analysis of US Patent 8213870 under 35 U.S.C. § 103

Under 35 U.S.C. § 103, an invention cannot be patented if the differences between the claimed invention and the prior art would have been obvious to a person having ordinary skill in the art (PHOSITA) before the effective filing date of the invention. The analysis for obviousness involves determining the scope and content of the prior art, ascertaining the differences between the claimed invention and the prior art, and resolving the level of ordinary skill in the pertinent art. An examiner may combine multiple prior art references to establish obviousness if there is a motivation to do so, leading to predictable results.

US Patent 8213870 generally describes beamforming using predefined spatial mapping matrices, particularly in a manner that aims to improve efficiency and range compared to traditional techniques involving explicit channel state information (CSI) feedback. The patent focuses on two main implementations:

1. Hopping between predefined spatial mapping matrices for data packet transmission without explicit channel training. This involves monitoring the quality of reception and switching matrices if the quality falls below a defined metric (as described in the abstract and further in the detailed description, particularly with reference to FIG. 2 and FIG. 4).
2. Directionally transmitting a sounding packet using a predefined spatial mapping matrix. This aims to extend the effective range of the sounding packet itself, leading to a broader reach for beamformed channels (as described with reference to FIG. 1 and FIG. 5).

The patent's "Prior Art keywords" (spatial mapping, receiver, predefined spatial, transmitter, received) and "Classifications" (e.g., H04B7/0456 for selection of precoding matrices or codebooks, H04B7/0617 for beamforming using weighted versions of the same signal, H04B7/0619 for feedback from the receiving side, H04B7/0626 for channel state information (CSI), and H04B7/0632 for channel quality indicator (CQI)) indicate the relevant technical field is wireless communication, particularly MIMO systems and beamforming.

Identifying Combinations of Prior Art References

To assess obviousness, a person having ordinary skill in the art (PHOSITA) in wireless communication systems, particularly MIMO and beamforming, would be aware of the existing challenges in traditional beamforming, such as system overhead and delayed data transmission due to sounding procedures.

While specific prior art documents are not provided in the prompt's "Prior art keywords" section, the "Definitions" and "Description" sections explicitly discuss "traditional beamforming" as the background art, which relies on channel state information (CSI) obtained through sounding packets where the sounding packet itself was not steered, leading to a limited effective transmission range and delays. The patent itself describes this as a problem it aims to solve.

Combination 1: Predefined Spatial Mapping Matrices for Data Transmission (without Sounding)

• Prior Art Elements:

  • MIMO wireless communication systems with multiple antennas at transmitter and receiver, capable of beamforming: This is a well-established concept in wireless communication, as acknowledged by the patent itself (e.g., IEEE 802.11n, 802.16e/j/m, 3GPP LTE standards).
  • Use of codebooks or sets of spatial mapping/precoding matrices for beamforming: The patent's classification H04B7/0456, "Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting," directly points to this as existing prior art. The general concept of a codebook of matrices for different beamforming directions is also foundational in MIMO systems for implicit or explicit feedback schemes.
  • Monitoring quality of reception (e.g., packet error rate, data rate) and adapting transmission parameters: The patent's classification H04L1/0001, "Systems modifying transmission characteristics according to link quality, e.g. power backoff," indicates the prior art of adapting transmissions based on link quality. The concept of monitoring packet error rates or data rates to assess link quality is standard in wireless communication for link adaptation.

• Motivation to Combine:
  A PHOSITA would be motivated to combine these elements to address the inherent inefficiencies of traditional explicit beamforming, specifically the overhead and delay associated with sounding procedures. Given that codebooks of spatial mapping matrices were known for beamforming, and techniques for adapting transmission based on link quality (like packet error rate or data rate) were also known, it would be an obvious step for a PHOSITA to try and directly use a predefined spatial mapping matrix from a codebook for data transmission, and then adapt this selection based on received quality metrics without a sounding procedure. The goal would be to reduce latency and overhead, which the patent itself identifies as drawbacks of the traditional approach. The patent explicitly states that traditional beamforming techniques "incur system overhead and sacrifice throughput" and were "inefficient and caused additional overhead". A PHOSITA would seek to overcome these known problems.

Combination 2: Directional Transmission of Sounding Packets

• Prior Art Elements:

  • Traditional explicit beamforming using sounding packets to obtain CSI: This is the baseline "traditional technique" described in the patent, where a sounding packet is sent, CSI is fed back, and a steering matrix (Q steer ) is formed to directionally transmit subsequent data.
  • Beamforming/directional transmission techniques: The fundamental principles of beamforming, including controlling phase and amplitude of signals across multiple antennas to create high-gain lobes in desired directions, are well-known. This includes the understanding that directional transmission extends effective range and improves SNR.

• Motivation to Combine:
  The patent acknowledges that in traditional beamforming, the sounding packet itself "was not steered" and "was traditionally transmitted using a spatial mapping matrix (Q) that was not directional". This resulted in the sounding packet having a "less than an effective transmission range" compared to the subsequent beamformed channel, thereby "limit[ing] traditional beamforming techniques at ranges that extend past the effective communication range of the sounding packet". A PHOSITA would be highly motivated to overcome this limitation. Recognizing that beamforming generally enhances range and reliability, it would be an obvious design choice to apply beamforming techniques to the sounding packet itself to increase its effective range and improve the probability of successful CSI acquisition. This directly addresses a recognized deficiency in the existing beamforming process described by the patent.

In both scenarios, the motivation stems from improving known aspects of MIMO wireless communication: increasing efficiency by reducing overhead and delay, and extending the effective range of communication. The elements combined are standard components and techniques within the field, and their combination to achieve predictable improvements would be evident to a PHOSITA.