# US 11,122,564 B2 · Doppler mode in a wireless network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,122,564 B2 - Document ID: US11122564B2 - Status: Granted - Kind: B2 - Application number: 16/362,529 - Filed: 2019-03-22 - Published: 2019-09-26 - Granted: 2021-09-14 - Earliest claimed: 2018-03-22 - Assignees: Newracom, Inc. - Applicants: Newracom, Inc. - Inventors: Yujin Noh; Seung Hyeok Ahn; Yongsuk Hwang; Dae Kyun Lee; Jong-ee Oh; Jaeyoung Ryu - Web page: https://patentgrep.com/patent/US11122564B2 ## CPC - H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals} - H04W 72/0446: Resources in time domain, e.g. slots or frames - H04L 69/22: Parsing or analysis of headers - H04W 72/1263: Mapping of traffic onto schedule, e.g. scheduled allocation or multiplexing of flows - H04W 72/51: based on terminal or device properties - H04L 1/188: {Time-out mechanisms} - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04W 84/005: {Moving wireless networks} - 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) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A process for receiving a Physical Layer Protocol Data Unit (PPDU) may include receiving a first portion of the PPDU. The first portion including a Legacy Signal (L-SIG) field and a second signal field that is received after the reception of the L-SIG field. The process further includes decoding, using first information in the L-SIG field, the second signal field, and determining, using second information included in the second signal field, that the PPDU includes midambles. In response to determining that the PPDU includes midambles, the process determines, using a midamble periodicity M, a number of midambles NMA in the PPDU, determines, using the number of midambles, a number of data symbols in a data field of the PPDU, and processes, using the number of midambles and the number of data symbols, the data field of the PPDU. The process may be performed by a wireless device. ## Claims ### Claim 1 A method performed by a wireless device, the method comprising: receiving a first portion of a Physical Layer Protocol Data Unit (PPDU), the first portion including a Legacy Signal (L-SIG) field and a second signal field, the second signal field being received after the reception of the L-SIG field, and the L-SIG field includes a Length field with a value of LENGTH; decoding, using first information in the L-SIG field, the second signal field; determining, using second information included in the second signal field, that the PPDU includes midambles; in response to determining that the PPDU includes midambles: determining, using a midamble periodicity M, a number of midambles NMA in the PPDU, determining, using the number of midambles, a number of data symbols in a data field of the PPDU, and processing, using the number of midambles and the number of data symbols, the data field of the PPDU, wherein determining the number of midambles NMA includes determining the number of midambles NMA according to: N MA = ⌊ X · ( LENGTH + 3 ) 3 - T PA - T SYM · β T MA + M · T SYM ⌋ or according to: N MA = ⌈ X · ( LENGTH + 3 ) 3 - T PA - T SYM ⁡ ( M + β ) T MA + M · T SYM ⌉ wherein TPA is a duration of a preamble, the preamble including the second signal field, TMA is a duration of a midamble, TSYM is a duration of the data symbols of the data field, β is a predetermined integer number greater than or equal to one, and X is a positive integer value. ### Claim 2 (depends on 1) The method of claim 1, wherein the second information includes an indication having a first state when the PPDU does not include midambles and a second state when the PPDU includes midambles. ### Claim 3 (depends on 2) The method of claim 2, wherein the second information further includes an indication of the midamble periodicity M. ### Claim 4 (depends on 2) The method of claim 2, wherein the midamble periodicity M is a predetermined number. ### Claim 5 (depends on 1) The method of claim 1, wherein β is one of 1, 2, or 4. ### Claim 6 (depends on 1) The method of claim 1, wherein receiving the data field comprises: receiving a plurality of consecutive data symbols equal to the midamble periodicity M; receiving a midamble immediately following the plurality of consecutive data symbols; characterizing the channel using the midamble; and receiving one or more remaining consecutive data symbols using the results of characterizing the channel using the midamble. ### Claim 7 (depends on 6) The method of claim 6, wherein a total number of subcarriers used to carry information in a data symbol is greater than a total number of subcarriers used to carry information in a symbol of the L-SIG field, and wherein the midamble permits channel characterization for every subcarrier used to carry information in the data symbol. ### Claim 8 A wireless device comprising: a receiver; and a processor, the processor configured to perform: receiving, using the receiver, a first portion of a Physical Layer Protocol Data Unit (PPDU), the first portion including a Legacy Signal (L-SIG) field and a second signal field, the second signal field being received after the reception of the L-SIG field; decoding, using first information in the L-SIG field, the second signal field; determining, using second information included the second signal field, that the PPDU includes midambles; in response to determining that the PPDU includes midambles: determining, using a midamble periodicity M, a number of midambles NMA in the PPDU, determining, using the number of midambles, a number of data symbols in a data field the PPDU, and processing, using the number of midambles and the number of data symbols, the data field of the PPDU, wherein the second information includes an indication having a first state when the PPDU does not include midambles and a second state when the PPDU includes midambles, wherein the L-SIG field includes a Length field with a value of LENGTH, and wherein determining the number of midambles NMA includes determining the number of midambles NMA according to: N MA = ⌊ X · ( LENGTH + 3 ) 3 - T PA - T SYM · β T MA + M · T SYM ⌋ or according to: N MA = ⌈ X · ( LENGTH + 3 ) 3 - T PA - T SYM ⁡ ( M + β ) T MA + M · T SYM ⌉ wherein TPA is a duration of a preamble, the preamble including the second signal field, TMA is a duration of a midamble, TSYM is a duration of the data symbols of the data field β is a predetermined integer number greater than or equal to one, and X is a positive integer value. ### Claim 9 (depends on 8) The wireless device of claim 8, wherein β is one of 1, 2, or 4. ### Claim 10 A method performed by a wireless device, the method comprising: generating a first portion of a Physical Layer Protocol Data Unit (PPDU), the first portion including a Legacy Signal (L-SIG) field and a second signal field, the second signal field is after the L-SIG field, and the L-SIG field includes a Length field with a value of LENGTH; determining, using a midamble periodicity M and a number of data symbols NSYM, a number of midambles NMA to include in the PPDU according to: NMA=└(NSYM−1)/M┘ generating, using the number of midambles NMA and the number of data symbols NSYM, a second portion of the PPDU, including the data field of the PPDU; determining the value of LENGTH according to: LENGTH ⁢ = ⌈ TXTIME - T PREAMBLE - T SIGNAL X ⌉ × 3 - 3 or according to: LENGTH = TXTIME - T PREAMBLE - T SIGNAL X × 3 - 3 where TXTIME is determined according to: TXTIME = T PREAMBLE + T SIGNAL + T SIG ⁡ ( s ) + X × ⌈ T PREAMBLE ⁢ 2 + N SYM ⁢ T SYM + N MA ⁢ T MA X ⌉ where TPREAMBLE is a summation of a duration of a legacy short training field (L-STF) and a legacy long training field (L-LTF) in the PPDU; TSIGNAL is a duration of the L-SIG field in the PPDU; TSIG(S) is a duration of symbols in a set of non-legacy signal fields in the PPDU, including the second signal field; TPREAMBLE2 is equal to a combined duration of symbols in a non-legacy short training field (STF) and a non-legacy long training field (LTF) in the PPDU; TSYM is a duration of each data symbol in the PPDU; TMA is a duration of each midamble field in the PPDU; and X is a positive integer value; and transmitting the PPDU on a channel to a set of wireless devices. ### Claim 11 (depends on 10) The method of claim 10, wherein the second signal field has information that includes an indication of the midamble periodicity M. ### Claim 12 (depends on 10) The method of claim 10, wherein transmitting the PPDU on the channel comprises: transmitting a plurality of consecutive data symbols on the channel equal to the midamble periodicity M; transmitting a midamble immediately following the plurality of consecutive data symbols on the channel, wherein the midamble is to be used by the set of stations for characterizing the channel; and transmitting one or more remaining consecutive data symbols on the channel. ### Claim 13 (depends on 12) The method of claim 12, wherein a total number of subcarriers used to carry information in a data symbol is greater than a total number of subcarriers used to carry information in a symbol of the L-SIG field, and wherein the midamble permits channel characterization for every subcarrier used to carry information in the data symbol.