US 9,444,577 Calibration correction for implicit beamformer using an explicit beamforming technique in a wireless MIMO communication system
5 defendants · 5 suits · updated September 14, 2026
Also cited as U.S. Patent No. 9,444,577 · US9444577B1 · US 9,444,577 B1 · 9444577 · the '577 patent
Velocity Communication Technologies, LLC has filed 5 patent-infringement suits on US 9,444,577, "Calibration correction for implicit beamformer using an explicit beamforming technique in a wireless MIMO communication system" since July 30, 2026, 3 of them in the E.D. Tex., against 5 distinct defendants including Arcadyan Technology Corporation, Calix, Inc. and Sercomm Corporation. The patent was granted September 13, 2016 on a priority date of April 5, 2010. Its abstract opens: "A bi-directionally calibrated beamforming technique for use in a MIMO wireless communication system includes a transmitter communicating a calibration initiation signal to a receiver requesting the receiver send a non-sounding packet containing an estimated…" The examiner cited 5 references during prosecution.
- Assignee
- Velocity Communication Technologies LLC
- Priority date
- April 5, 2010
- Granted
- September 13, 2016
- Expires
- April 5, 2030
- Status
- Active
- Claims
- 25 (2 independent)
- Inventors
- Hongyuan Zhang, Rohit U. Nabar, Sudhir Srinivasa
- Full text
- Google Patents
The suits
5 cases · E.D. Tex. (3) · D. Del. (2)
| Filed | Defendant | Plaintiff | Court | Docket |
|---|---|---|---|---|
| 2026-07-30 | Arcadyan Technology Corporation | Velocity Communication Technologies, LLC | E.D. Tex. | 5:26-cv-00102 |
| 2026-07-30 | Calix, Inc. | Velocity Communication Technologies, LLC | D. Del. | 1:26-cv-00937 |
| 2026-07-30 | Sercomm Corporation | Velocity Communication Technologies, LLC | E.D. Tex. | 5:26-cv-00101 |
| 2026-07-30 | TCL Electronics Holdings Limited | Velocity Communication Technologies, LLC | E.D. Tex. | 5:26-cv-00103 |
| 2026-07-30 | Vistance Networks, Inc. | Velocity Communication Technologies, LLC | D. Del. | 1:26-cv-00944 |
Docket links open the public record on CourtListener. Filing dates are the complaint's.
Independent claims
What is actually asserted, verbatim.
1. A method of beamforming within a communication system having (i) a first transceiver device having a first plurality of antennas and (ii) a second transceiver device having a second plurality of antennas, the method comprising: transmitting, from the first transceiver device to the second transceiver device, via a forward channel a first calibration signal requesting a non-sounding packet from the second transceiver device, where the non-sounding packet from the second transceiver device is to include a description of the forward channel; receiving, at the first transceiver device, via a reverse channel the non-sounding packet from the second transceiver device; receiving, at the first transceiver device from the second transceiver device, via the reverse channel a second calibration signal requesting a non-sounding packet from the first transceiver device, where the non-sounding packet from the first transceiver device is to include a description of the reverse channel; determining, at the first transceiver device, (i) a partial dimensional description of the reverse channel based on receipt of the non-sounding packet from the second transceiver device or (ii) a full dimensional description of the reverse channel based on receipt of the second calibration signal requesting the non-sounding packet from the first transceiver device; and determining, at the first transceiver device, a first device correction matrix from the received non-sounding packet from the second transceiver device and (i) the partial dimensional description of the reverse channel or (ii) full dimensional description of the reverse channel, wherein the first transceiver is to use the correction matrix to process signals to be transmitted via the forward channel, where the first device correction matrix is for use in transmitting data via the forward channel.
19. An apparatus, comprising: a first transceiver device having one or more integrated circuit devices configured to transmit a first calibration signal to a second transceiver device via a forward channel, the first calibration signal requesting a non-sounding packet from the second transceiver device, where the non-sounding packet from the second transceiver device is to include a description of the forward channel, receive the non-sounding packet from the second transceiver device via a reverse channel, receive a second calibration signal from the second transceiver device via the reverse channel, the second calibration signal requesting a non-sounding packet from the first transceiver device, where the non-sounding packet from the first transceiver device is to include a description of the reverse channel, determine (i) a partial dimensional description of the reverse channel based on receipt of the non-sounding packet from the second transceiver device or (ii) a full dimensional description of the reverse channel based on receipt of the second calibration signal requesting the non-sounding packet from the first transceiver device, determine a first device correction matrix from the received non-sounding packet from the second transceiver device and (i) the partial dimensional description of the reverse channel or (ii) full dimensional description of the reverse channel, and use the first device correction matrix to process signals transmitted via the forward channel.
Art before the examiner
25 references of record, 5 cited by the examiner.
Everything listed here was before the Office and is what a challenge must go beyond. Art the examiner never saw is where an invalidity search starts.
Examiner-cited
- US20080089396A1 — Calibration Correction for Implicit Beamforming in a Wireless MIMO Communication System (Hongyuan Zhang)
- US20090203376A1 — Suitable trigger mechanism to control new cell identification in ue when in drx mode (Qualcomm, Incorporated)
- US20100172425A1 — Method and apparatus for closed loop beamforming for mimo ofdm wireless communication systems (Ralink Technology Corporation)
- US20110194475A1 — Preamble and header bit allocation for power savings within multiple user, multiple access, and/or MIMO wireless communications (Broadcom Corporation)
- US8971178B1 — Calibration correction for implicit beamformer using an explicit beamforming technique in a wireless MIMO communication system (Marvell International Ltd.)
Applicant-cited and other (20)
- US6584161B2 — Transmit diversity method and system
- US20030224750A1 — Method and system for multiple channel wireless transmitter and receiver phase and amplitude calibration
- US20050064908A1 — Apparatus, and associated method, for assigning data to transmit antennas of a multiple transmit antenna transmitter
- US20060063492A1 — Measurement support for a smart antenna in a wireless communication system
- US20060104382A1 — Method and apparatus for transmitting/receiving signals in multiple input multiple output wireless communication system employing beam forming scheme
- US20060176977A1 — Method and apparatus for use of space time trellis codes based on channel phase feedback
- US7206354B2 — Calibration of downlink and uplink channel responses in a wireless MIMO communication system
- US20070127586A1 — Multiple stream co-phasing for multiple-input-multiple-output (mimo) systems
- US20070195811A1 — Wireless communication system, associated methods and data structures
- US20070268181A1 — Derivation and feedback of transmit steering matrix
- US20080095268A1 — Method and system for choice of a steering matrix (q) for sounding in antenna selection
- US7486740B2 — Calibration of transmit and receive chains in a MIMO communication system
- US7570210B1 — Steering matrix feedback for beamforming
- US7599332B2 — Modified preamble structure for IEEE 802.11a extensions to allow for coexistence and interoperability between 802.11a devices and higher data rate, MIMO or otherwise extended devices
- US20100074237A1 — Method for transmitting and identifying transmit power value in multi-user mimo
- US20100091675A1 — Wireless communication system, wireless communication device and wireless communication method, and computer program
- US7742390B2 — Method and apparatus for improved long preamble formats in a multiple antenna communication system
- US20120039196A1 — Sub-band feedback for beamforming on downlink multiple user mimo configurations
- US8270909B2 — Sounding and steering protocols for wireless communications
- US8619907B2 — Method and apparatus for preamble training in a multiple antenna communication system
Classification
- H04L1/0026primary — Transmission of channel quality indication
- H04B7/0413 — MIMO systems
- H04B7/0617 — Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
- H04B7/0619 — Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
- H04B7/0667 — Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of delayed versions of same signal
- H04B7/068 — Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission using space frequency diversity
- H04L1/16 — Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
- H04L25/0204 — Channel estimation of multiple channels
- H04L25/0206
- H04L25/03 — Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
- H04L25/03949 — Spatial equalizers equalizer selection or adaptation based on feedback
Family
- US9444577B1 — B1 (2016)
Abstract
A bi-directionally calibrated beamforming technique for use in a MIMO wireless communication system includes a transmitter communicating a calibration initiation signal to a receiver requesting the receiver send a non-sounding packet containing an estimated description of the forward channel. The receiver also sends a sounding packet to the transmitter. The transmitter determining a partial or full estimated description of a reverse channel based on the received non-sounding packet and/or the receiving sounding packet. The transmitter further determines one or more transmitter correction matrices from receiving estimated description of the forward channel and the partial or full estimated description of the reverse channel. The transmitter sending the partial or full estimated description of the reverse channel to the receiver, which determines one or more receiver correction matrices.
Also asserted by Velocity Communication Technologies, LLC
- US 10,200,096 — Beamforming using predefined spatial mapping matrices (5 defendants)
- US 8,213,870 — Beamforming using predefined spatial mapping matrices (5 defendants)
- US 8,238,832 — Antenna optimum beam forming for multiple protocol coexistence on a wireless device (5 defendants)
- US 8,260,213 — Method and apparatus to adjust a tunable reactive element (5 defendants)
- US 8,265,573 — Wireless subscriber communication unit and method of power control with back-off therefore (5 defendants)
- US 8,270,343 — Broadcasting of textual and multimedia information (5 defendants)
- US 8,644,765 — Beamforming using predefined spatial mapping matrices (5 defendants)
- US 8,675,570 — Scalable OFDM and OFDMA bandwidth allocation in communication systems (5 defendants)
- US 9,083,401 — Beamforming using predefined spatial mapping matrices (5 defendants)
- US 9,596,648 — Unified beacon format (5 defendants)
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This page is assembled from public records — federal court dockets and the patent's own file — and is updated as the case list changes. It states what the record shows and is not an opinion on the validity or infringement of any claim. Patent data via Google Patents; docket data via CourtListener.