# US 12,184,463 B2 · Long training field sequence construction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,463 B2 - Document ID: US12184463B2 - Status: Granted - Kind: B2 - Application number: 18/306,354 - Filed: 2023-04-25 - Published: 2023-08-17 - Granted: 2024-12-31 - Earliest claimed: 2015-03-25 - Assignees: Atlas Global Technologies LLC - Applicants: Atlas Global Technologies LLC - Inventors: Daewon Lee; Sungho Moon; Yujin Noh; Minho Cheong - Web page: https://patentgrep.com/patent/US12184463B2 ## CPC - H04L 27/2613: {Structure of the reference signals} - H04L 25/00: Baseband systems - H04L 25/0204: {of multiple channels} - H04L 25/0226: {sounding signals per se} - H04L 27/26: Systems using multi-frequency codes (H04L27/32 takes precedence) - H04W 28/065: {using assembly or disassembly of packets} - H04B 7/0452: Multi-user MIMO systems - H04L 1/0643: {block codes} - H04L 27/26132: {using repetition} - H04L 27/2614: {Peak power aspects} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION ## Abstract An apparatus is provided. The apparatus performs operations including selecting a high efficiency long training field (HE LTF) sequence for a frame, selecting an HE LTF transmission mode from one of a 4× HE LTF mode, a 2× HE LTF mode, and a 1× HE LTF mode, transmitting only a set of allocated subcarriers of the HE LTF sequence for the frame, and transmitting a set of additional fields of the frame using the set of allocated subcarriers and a set of unallocated subcarriers. The set of additional fields includes a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a high efficiency signaling A field (HE-SIG-A), and a high efficiency short training field (HE-STF). Transmitting of the HE LTF sequence for the frame uses only one or more of the set of allocated subcarriers, and none of the unallocated subcarriers. ## Claims ### Claim 1 An apparatus for facilitating wireless communication, the apparatus comprising: one or more memories comprising instructions; and one or more processors coupled to the one or more memories, wherein when the one or more processors execute the instructions, the apparatus performs operations comprising: selecting, based on a bandwidth of a frame, a high efficiency long training field (HE-LTF) sequence for the frame; selecting an HE-LTF transmission mode from one of a 4× HE-LTF mode, a 2× HE-LTF mode, and a 1× HE-LTF mode; transmitting, to a set of stations, only a set of allocated subcarriers of the HE-LTF sequence for the frame, wherein each subcarrier in the set of allocated subcarriers is allocated to a station in the set of stations for the frame; and transmitting, to the set of stations, a set of additional fields of the frame using the set of allocated subcarriers and a set of unallocated subcarriers, the set of additional fields including a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a high efficiency signaling A field (HE-SIG-A), and a high efficiency short training field (HE-STF), wherein transmitting of the HE-LTF sequence for the frame uses only one or more of the set of allocated subcarriers, and none of the unallocated subcarriers. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the set of unallocated subcarriers includes data subcarriers. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein when the one or more processors execute the instructions, the apparatus performs the operations comprising: transmitting the frame such that the set of unallocated subcarriers in the HE-LTF sequence have a value of zero. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the frame is part of a downlink orthogonal frequency division multiple access (OFDMA) transmission and the apparatus is an access point, and wherein when the one or more processors execute the instructions, the access point performs the operations comprising: determining allocation of subcarriers to the set of stations. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the access point modulates symbols associated with one or more data/pilot tones allocated to one or more stations for transmission. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the frame is part of an uplink orthogonal frequency division multiple access (OFDMA) transmission and the apparatus is a non-access point station, and wherein the set of stations includes an access point that sets the bandwidth of the frame. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the bandwidth of the frame is one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80+80 MHz. ### Claim 8 A method for facilitating wireless communication, the method comprising: selecting, by a wireless device based on a bandwidth of a frame, a high efficiency long training field (HE-LTF) sequence for the frame; selecting an HE-LTF transmission mode from one of a 4× HE-LTF mode, a 2× HE-LTF mode, and a 1× HE-LTF mode; transmitting, by the wireless device to a set of stations, only a set of allocated subcarriers of the HE-LTF sequence for the frame, wherein each subcarrier in the set of allocated subcarriers is allocated to a station in the set of stations for the frame; and transmitting, by the wireless device to the set of stations, a set of additional fields of the frame using the set of allocated subcarriers and a set of unallocated subcarriers, the set of additional fields including a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a high efficiency signaling A field (HE-SIG-A), and a high efficiency short training field (HE-STF), wherein transmitting of the HE-LTF sequence for the frame uses only one or more of the set of allocated subcarriers, and none of the unallocated subcarriers. ### Claim 9 (depends on 8) The method of claim 8, wherein the set of unallocated subcarriers includes data subcarriers. ### Claim 10 (depends on 8) The method of claim 8, comprising: transmitting the frame such that the set of unallocated subcarriers in the HE-LTF sequence have a value of zero. ### Claim 11 (depends on 8) The method of claim 8, wherein the frame is part of a downlink orthogonal frequency division multiple access (OFDMA) transmission and the wireless device is an access point, and wherein when the one or more processors execute the instructions, the access point performs operations comprising: determining allocation of subcarriers to the set of stations. ### Claim 12 (depends on 8) The method of claim 8, wherein the frame is part of a downlink orthogonal frequency division multiple access (OFDMA) transmission, and wherein the method comprises: determining allocation of subcarriers to the set of stations. ### Claim 13 (depends on 8) The method of claim 8, wherein the frame is part of an uplink orthogonal frequency division multiple access (OFDMA) transmission and the apparatus is a non-access point station, and wherein the set of stations includes an access point that sets the bandwidth of the frame. ### Claim 14 (depends on 8) The method of claim 8, wherein the bandwidth of the frame is one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80+80 MHz. ### Claim 15 A non-transitory machine-readable storage medium that stores instructions, which when executed by one or more processors of a wireless device, cause the wireless device to: select, based on a bandwidth of a frame, a high efficiency long training field (HE-LTF) sequence for the frame; select an HE-LTF transmission mode from one of a 4× HE-LTF mode, a 2× HE-LTF mode, and a 1× HE-LTF mode; transmit, to a set of stations, only a set of allocated subcarriers of the HE-LTF sequence for the frame, wherein each subcarrier in the set of allocated subcarriers is allocated to a station in the set of stations for the frame; and transmit, to the set of stations, a set of additional fields of the frame using the set of allocated subcarriers and a set of unallocated subcarriers, the set of additional fields includes a legacy short training field (L-STF), a legacy long training field (L-LTF), a legacy signaling field (L-SIG), a high efficiency signaling A field (HE-SIG-A), and a high efficiency short training field (HE-STF), wherein the transmission of the HE-LTF sequence for the frame uses only one or more of the set of allocated subcarriers, and none of the unallocated subcarriers. ### Claim 16 (depends on 15) The non-transitory machine-readable storage medium of claim 15, wherein the set of unallocated subcarriers includes data subcarriers. ### Claim 17 (depends on 15) The non-transitory machine-readable storage medium of claim 15, wherein when the one or more processors execute the instructions, the wireless device is caused to perform operations comprising: transmitting the frame such that the set of unallocated subcarriers in the HE-LTF sequence have a value of zero. ### Claim 18 (depends on 15) The non-transitory machine-readable storage medium of claim 15, wherein the frame is part of a downlink orthogonal frequency division multiple access (OFDMA) transmission and the wireless device is an access point, and wherein when the one or more processors execute the instructions, the access point performs operations comprising: determining allocation of subcarriers to the set of stations. ### Claim 19 (depends on 18) The non-transitory machine-readable storage medium of claim 18, wherein the access point modulates symbols associated with one or more data/pilot tones allocated to one or more stations for transmission. ### Claim 20 (depends on 15) The non-transitory machine-readable storage medium of claim 15, wherein the frame is part of an uplink orthogonal frequency division multiple access (OFDMA) transmission and the apparatus is a non-access point station, and wherein the set of stations includes an access point that sets the bandwidth of the frame.