Invalidity dossier
US 8971178
Calibration correction for implicit beamformer using an explicit beamforming technique in a wireless MIMO communication system
Current assignee: Velocity Communication Technologies LLC
Added 9/21/2026, 10:41:44 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US 8,971,178 B1
Title: "Calibration correction for implicit beamformer using an explicit beamforming technique in a wireless MIMO communication system"
Patent number / application: US 8,971,178 B1, application US 13/077,485.
Inventors: Rohit U. Nabar, Hongyuan Zhang, Bo Wang.
Assignee history as listed: Originally assigned to Marvell International Ltd. (with an assignment recorded from Marvell Semiconductor, Inc.). Later reassignments to NXP USA, Inc. and, per the listing, a current assignee of Velocity Communication Technologies LLC. Because the source itself cautions that listed assignees "may be inaccurate," these are reported as listed rather than verified.
Key dates: Priority date 2010-04-05; filing date 2011-03-31; publication/grant date 2015-03-03; adjusted expiration listed as 2032-11-30 (status listed as active). A related filing, US 14/190,988, is noted as claiming priority.
Technical field / classifications: Wireless radio transmission using multiple antennas — MIMO systems (H04B7/0413), transmit-side beamforming (H04B7/0617), beamforming with receiver feedback (H04B7/0619), plus channel estimation and spatial equalizers (H04L25/0202, H04L25/022, H04L25/03949). The description situates the invention among 802.11a/g/n and 802.16a/d/e/m OFDM systems.
Purpose and plain-language scope: The patent addresses beamforming in wireless systems having multiple transmit and multiple receive antennas. The title frames the core idea: using an explicit beamforming technique to correct calibration for an implicit beamformer. In implicit beamforming, a transmitter infers the forward (transmit-to-receive) channel from the reverse channel, which requires the transmit and receive chains to be calibrated relative to each other; this patent concerns correcting that calibration. The background describes OFDM transmitters performing encoding, IFFT, digital-to-analog conversion, RF upconversion, and power amplification.
Source: https://patents.google.com/patent/US8971178/en
What the excerpt does not establish: It does not include the claims, detailed description, or figures, so the specific calibration/correction steps, claim scope, and embodiments cannot be stated; nor does it verify assignee accuracy, legal status, or expiration, which the source itself labels as assumptions or non-legal conclusions.
Generated 10/1/2026, 10:01:16 PM
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Litigation summary
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PTAB challenges
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Assignment history
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Prior art
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Obviousness
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Extensions
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Derivative works
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