# US 10,122,510 B2 · Method, apparatus, and computer readable medium for signaling high efficiency packet formats using a legacy portion of the preamble in wireless local-area networks > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,510 B2 - Document ID: US10122510B2 - Status: Granted - Kind: B2 - Application number: 15/603,791 - Filed: 2017-05-24 - Published: 2017-09-14 - Granted: 2018-11-06 - Earliest claimed: 2015-01-21 - Assignees: Intel IP Corporation - Applicants: Intel IP Corporation - Inventors: Shahrnaz Azizi; Robert J. Stacey; Thomas J. Kenney; Eldad Perahia - Web page: https://patentgrep.com/patent/US10122510B2 ## CPC - H04L 27/2603: {Signal structure ensuring backward compatibility with legacy system} - H04B 1/40: Circuits - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 27/22: Demodulator circuits; Receiver circuits - H04L 27/2613: {Structure of the reference signals} - H04L 69/323: in the physical layer [OSI layer 1] - H04W 84/12: WLAN [Wireless Local Area Networks] - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Methods, apparatuses, and computer readable media for signaling high-efficiency packet formats using a legacy portion of the preamble in wireless local-area networks are disclosed. A high-efficiency (HE) wireless local area network (HEW) device including circuitry is disclosed. The circuitry may be configured to generate a HE packet comprising a legacy signal field (L-SIG) followed by one or more HE signal fields, and configure the L-SIG to signal to a second HEW device either a first packet format of the HE packet or a second packet format of the HE packet, where a length of the L-SIG modulo 3 is used to signal the first packet format or the second packet format. The circuitry may be configured to generate a duplicated L-SIG field with a polarity difference to indicate a third packet configuration of the HE packet or a fourth packet configuration of the HE packet. ## Claims ### Claim 1 An apparatus of high-efficiency (HE) station (STA), the apparatus comprising: memory; and, processing circuitry coupled to the memory, the processing circuitry configured to: decode a preamble comprising a first portion, the first portion comprising a legacy signal field (L-SIG) and a repeated (R) L-SIG (RL-SIG), wherein the RL-SIG indicates that the preamble is part of a high-efficiency (HE) Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU)(HE-PPDU), and wherein the L-SIG comprises a length field; and decode a second portion of the preamble in accordance with a first HE PPDU format if a value of the length field modulo three equals one, and process the second portion in accordance with a second HE PPDU format if the value of the length field modulo three equals two. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the preamble further comprises a legacy short-training field (L-STF) and a legacy long-training field (L-LTF). ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the first HE PPDU format further comprises a HE-SIG-A field, the HE-SIG-A field comprising a format field that indicates whether the first HE PPDU format is a third HE PPDU format or a fourth HE PPDU format. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the third HE PPDU format and the fourth HE PPDU format both further comprise a HE short-training field (STF) immediately following the HE-SIG-A. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein the third HE PPDU format is a single user (SU) HE PPDU format. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the second portion further comprises a HE-SIG-A field that indicates whether the second HE PPDU format is either a fifth HE PPDU format or a sixth HE PPDU format. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein the HE-SIG-A field indicates that the fifth HE PPDU format is a multi-user (MU) format with a HE-SIG-B field immediately following the HE-SIG-A field. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the processing circuitry is further configured to: decode the L-SIG and the RL-SIG in accordance with binary phase-shift keying (BPSK) modulation. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the L-SIG and the RL-SIG are each one symbol. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the value of the length field modulo three equal to zero indicates the preamble is part of a legacy PPDU. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the HE STA is configured to operate in accordance with Institute of Electrical and Electronic Engineers (IEEE) 802.11ax, and the HE STA is an HE AP or an HE STA. ### Claim 12 (depends on 1) The apparatus of claim 1, further comprising transceiver circuitry coupled to the processing circuitry. ### Claim 13 (depends on 12) The apparatus of claim 12, further comprising one or more antennas coupled to the transceiver circuitry. ### Claim 14 A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors, the instructions to configure the one or more processors to cause an apparatus of a high-efficiency (HE) station (STA) to: decode a preamble comprising a first portion, the first portion comprising a legacy signal field (L-SIG) and a repeated (R) L-SIG (RL-SIG), wherein the RL-SIG indicates that the preamble is part of a high-efficiency (HE) Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU)(HE-PPDU), and wherein the L-SIG comprises a length field; and decode a second portion of the preamble in accordance with a first HE PPDU format if a value of the length field modulo three equals one, and process the second portion in accordance with a second HE PPDU format if the value of the length field modulo three equals two. ### Claim 15 (depends on 14) The non-transitory computer-readable storage medium of claim 14, wherein the preamble further comprises a legacy short-training field (L-STF) and a legacy long-training field (L-LTF). ### Claim 16 (depends on 14) The non-transitory computer-readable storage medium of claim 14, wherein the first HE PPDU format further comprises a HE-SIG-A field, the HE-SIG-A field comprising a format field that indicates whether the first HE PPDU format is a third HE PPDU format or a fourth HE PPDU format. ### Claim 17 (depends on 14) The non-transitory computer-readable storage medium of claim 14, wherein the third HE PPDU format and the fourth HE PPDU format both further comprise a HE short-training field (STF) immediately following the HE-SIG-A. ### Claim 18 A method performed by an apparatus of an high-efficiency (HE) station (STA), the method comprising: decoding a high-efficiency (HE) Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU)(HE-PPDU) preamble comprising a first portion, the first portion comprising a legacy signal field (L-SIG) and a repeated (R) L-SIG (RL-SIG), and wherein the L-SIG comprises a length field; and decoding a second portion of the preamble in accordance with a first HE PPDU format if a value of the length field modulo three equals one, and process the second portion in accordance with a second HE PPDU format if the value of the length field modulo three equals two. ### Claim 19 (depends on 18) The method of claim 18, wherein the preamble further comprises a legacy short-training field (L-STF) and a legacy long-training field (L-LTF). ### Claim 20 An apparatus of high-efficiency (HE) station (STA) com, the apparatus comprising: memory; and, processing circuitry coupled to the memory, the processing circuitry configured to: encode a preamble of a physical layer convergence procedure (PLCP) protocol data unit (PPDU), the preamble comprising a legacy portion comprising a legacy signal field (L-SIG) and a repeated (R) L-SIG (RL-SIG), wherein the RL-SIG indicates that the preamble is part of a high-efficiency (HE) Physical Layer Convergence Protocol (PLCP) Protocol Data Unit (PPDU)(HE-PPDU), and wherein the L-SIG comprises a length field; encode the value of the length field to be one modulo three if the subsequent portion is a first HE PPDU format, or encode the value of the length field to be two modulo three if the subsequent portion is a second HE PPDU format; and configure the HE STA to wirelessly transmit the PPDU to an access point. ### Claim 21 (depends on 20) The apparatus of claim 20, wherein the first HE PPDU format further comprises a HE-SIG-A field comprising a format field that indicates whether the first HE PPDU format is a third HE PPDU format or a fourth HE PPDU format. ### Claim 22 (depends on 21) The apparatus of claim 21, wherein the third HE PPDU format and the fourth HE PPDU format both further comprise a HE short-training field (STF) immediately following the HE-SIG-A. ### Claim 23 (depends on 22) The apparatus of claim 22, wherein the third HE PPDU format and the fourth HE PPDU format both further comprise a HE short-training field (STF) immediately following the HE-SIG-A. ### Claim 24 (depends on 23) The apparatus of claim 23, wherein the third HE PPDU format is a single user (SU) HE PPDU format. ### Claim 25 (depends on 20) The apparatus of claim 20, further comprising transceiver circuitry coupled to the processing circuitry; and, one or more antennas coupled to the transceiver circuitry.