US 9628310

Here's a concise summary of US Patent 9628310:

Patent Number: US9628310B2
Title: Long training field sequence construction
Current Assignee: Atlas Global Technologies LLC
Inventors: Daewon Lee, Sungho Moon, Yujin Noh, Minho Cheong
Filing Date: March 23, 2016
Issue Date: April 18, 2017

Abstract:
The patent discloses techniques for constructing long training field (LTF) sequences for preambles of high-efficiency (HE)-based transmissions, often referred to as HE LTF sequences. These sequences are evaluated using peak-to-average power ratio (PAPR), with lower PAPR values being more desirable. Implementations include constructing HE LTF sequences for various channel bandwidths (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, and 80+80 MHz). Phase rotation can be applied to blocks of tones within an HE LTF sequence, potentially including reserved tones, and hierarchical phase rotation may be used. The patent also describes optimizing usable center tones to lower PAPR values. In some implementations, an HE LTF sequence can be subsampled, transmitting about half of its elements. For orthogonal frequency-division multiple access (OFDMA) communication, a station may transmit an HE LTF sequence only for its allocated tones, while an access point transmits it for allocated data/pilot tones and reserved tones. This approach aims to achieve lower PAPR and/or higher transmission efficiency in wireless communications utilizing HE LTF sequences.

Plain-Language Overview of Independent Claims:

• Independent Claim 1 (Method): This claim describes a method performed by a wireless communication device for creating a Long Training Field (LTF) sequence within a High Efficiency (HE) preamble for transmission. The method involves defining an HE LTF sequence for a specific channel bandwidth, where this sequence includes multiple tones (subcarriers) with corresponding tone indices. A key step is applying phase rotation to a subset of these tones based on their tone indices. The phase rotation values are determined by checking if a tone's index falls within certain ranges (e.g., less than -64, between -64 and -1, between 0 and 63, or greater than 63). Different phase rotation values (like 1, -1, j, or -j) are applied depending on these ranges. This processed HE LTF sequence is then transmitted.
• Independent Claim 11 (Apparatus): This claim describes a wireless communication apparatus designed to construct and transmit an LTF sequence for an HE preamble. The apparatus includes a baseband processor configured to perform the same steps as outlined in Claim 1: define the HE LTF sequence, apply phase rotation to subsets of tones based on their indices and predefined phase rotation values (1, -1, j, or -j) corresponding to specific tone index ranges, and then transmit this sequence.
• Independent Claim 19 (Computer-Readable Medium): This claim covers a non-transitory computer-readable medium (like memory) that stores instructions. When these instructions are executed by one or more processors in a wireless communication device, they cause the device to perform the method described in Claim 1, i.e., constructing and transmitting the phase-rotated HE LTF sequence.

CAFC 2026 Dockets:
As of April 26, 2026, no specific cases related to patent US9628310 were found in the provided snippets of the U.S. Court of Appeals for the Federal Circuit's June 2026 scheduled cases.